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Time off work and symptoms after minor head injury
Injury. 12,445-454
Printedin
GreatBritain
445
Time off work and symptoms head injury Philip Wrightson Department
after minor
and Dorothy Gronwall
of Neurosurgery, Auckland Hospital, NewZealand
Summary
A carefully controlled prospective study was made of 66 men aged 17 to 48 with minor head injuries. The mean time off work was 4.7 days, range 0 to 26 days. Time off work was longer: in older patients; after road trafftc accidents compared with sports injuries; in patients who had taken alcohol and in 5 patients who had needed admission to hospital. Post-traumatic amnesia alone did not relate to time off work but was longer in these groups of patients. Sixty per cent of patients had symptoms on return to work and 46 per cent could not do their job as well as usual for a mean time of 14 days. Leisure activities were affected for a similar period and fatigue was common. Ninety days after the accident 20 per cent still had symptoms, mostly defects of memory, concentration and work capacity. Four patients still had symptoms 2 years later. Though describing symptoms, all patients were back at their usual work and none had any claim for compensation outstanding. Major points emerging are the limitations of posttraumatic amnesia as an index of the severity of a minor head injury, and the high incidence of symptoms on return to work and later, in patients who were at work and without compensation claims. The importance is stressed of an effective programme for the management of minor head injuries. INTRODUCTION MINOR head injuries economic importance.
are
of great
social
and
Not only does their care in the acute stages load the hospital services
industry (Cook, 1969; Muller, 1969; Cook, 1972), and when compensation is involved (Muller, 1969; Cook, 1972), and there is doubt about the relation of persisting symptoms to organic causes (Rutherford et al., 1979). It is plain that if minor head injury is to be managed efficiently, these uncertainties must be resolved. Although for this to be done the natural history of the injury must be known, the information available is mostly unsatisfactory. Much of it has been gathered retrospectively, samples have been unrepresentative and many factors have been uncontrolled. The recent studies of Rutherford et al. (1977; 1979) have avoided many ofthese difficulties, but the results have been partly obscured by the diversity of their patients and by the influence of compensation. This prospective study has tried to avoid these uncertainties by looking at minor head injury when recovery occurs under the simplest conditions. The sample is limited to young employed men. Post-traumatic amnesia, conventionally an important measure of the severity of injury, was determined with great care and precautions were taken to avoid suggesting symptoms to patients. Lastly, the nature of the sample, the mildness of the injury and the structure of New Zealand accident compensation law allowed the results to be relatively unaffected by considerations of compensation.
(Field, 1976) but persisting symptoms lead to disability and litigation (Rutherford et al., 1979). There is still difference of opinion on policies of acute care (Jennett et al., 1977), and provision for later management is rare. There are large differences in the period of disability
PATIENTS AND METHODS Sixty-six New Zealand men in regular
reported aRer comparable
ment aged 17-48,
injuries
in sport and
employwere studied. They had been
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brought to the Accident and Emergency Department of Auckland or Green Lane Hospital from 1600 to 2400 hours with a diagnosis of minor head injury. They were seen within 2 hours of the accident by one of us and included in the study if they were fit to return home after observation and if they had no other injury which would affect their return to work. Routine observations included serial tests of orientation, retrograde and post-traumatic amnesia (PTA), and also of recent memory. From the history and from the smell of alcohol in the breath or vomitus an estimate was made of whether the patient had taken alcohol before the accident; for medicolegal and ethical reasons blood was not taken for ethanol estimation. Details of the accident and of the patient’s age, employment and wages were noted. Patients were allotted to five groups for follow-up. The groups were balanced for age, occupation and the distribution of PTA duration. All were interviewed 90 days alter injury, and in addition those in groups I, II and III were seen at 7, 14 and 30 days respectively. Patients in group V were brought back to hospital again within 48 hours, given psychometric tests and counselled about the effects of concussion. The tests were repeated each week until the results had returned to normal. A sixth group was formed from patients who had been examined in the same way but who needed admission to hospital. They were followed up in the same way as group V patients. The patients were seen at the 90th day after the accident, as well as before then, by an occupational therapist who was experienced in the treatment of head injuries, and used the same questionnaire each time; this covered the following: 1. Memory for events before and alter the accident, to give estimates of retrograde and post-traumatic amnesia. For the present purpose, the end of PTA was taken to be the return of continuous memory. 2. The date of return to work, who had authorized this, and details of accident compensation. 3. How patients felt when they returned to work, whether they could do the job as well as usual, and ifnot, why. 4. What they usually did after work, and whether there had been any change in leisure activities or in the time at which they had gone to bed. 5. Symptoms. An open-ended question about any trouble since the accident was followed by
specific questions about 12 common symptoms -headache, photophobia, diplopia, tinnitus, dizziness, to noise, sensitivity deafness, tiredness, irritability, memory, concentration and difficulties at work. The interviews were all carried out in the patient’s home and were made as friendly and informal as possible, showing proper concern but not encouraging patients to dwell on symptoms. Family and friends were often present, and their comments were also recorded. This approach was well accepted, and only one patient refused to be seen a second time. The patients who were found to have persisting symptoms at 90 days were sought 2 years after the accideti. Only two-thirds were traced. They were interviewed again, using the same questionnaire, together with a sample of patients who had been free from symptoms, matched for age, occupation and cause of injury. These interviews were carried out by one of us (D.G.). RESULTS Time off work
In 66 patients the mean interval between the accident and return to work (time off work, TOW) was 4.7 days. If Sundays and holidays were excluded, the mean number of working days lost was 3.3 days. Fifty-four patients (81.8 per cent) returned to work between 0 and 7 days, 7 (10.6 per cent) between 8 and 14 days, and 5 (7.6 per cent) between 15 and 30 days after the injury was incurred. Accident
compensation
Only 3 of the 66 patients were injured at work. Two lost no working days, and 1 lost 2 working days. (Note: under New Zealand law, those unable to work because of an accident at work are paid by their employer for the first week of their disability. After 1 week, those unable to work because of an accident, however sustained, are paid compensation related to their earnings, irrespective of fault.) Of the 7 patients off work between 8 and 14 days who were eligible for compensation, only 2 applied for it; the 5 who were off work between 15 and 30 days all received compensation. Factors related to time off work Post-traumatic amnesia
The record of each patient contained key times and events following the accident, observed by others up to arrival at hospital and subsequently by one of us. However, even with these records, it was found that PTA of short duration could be
447
Wrightson and Gronwall: Minor Head Injury Table /. Distribution of PTA durations
Groups I-V VI
o-1 37 1
l-3
3-6
16 0
6 1
PTA (hours) 6-9
9-18
1 1
18-36
1 0
0 2
Total 61 5
Tab/e //. Relation of PTA to activity, all groups PTA Activity Road traffic Sport Other
Excluding alcohol < 60 min > 60 min
Full sample > 60 min < 60 min 4 25 9
14 12 2
2 25 5
5 12 0
RTA v. sport: full sampleX2 = 10.02, P ~0.01, excluding alcohol P= 0.06. Other v. sport: full sample P= 0.2 1, excluding alcohol P= 0.17. RTA v. other: full sample P= 0.002, excluding alcohol P= 0.03. (Exact probabilities).
Tab/e///. Relation of PTA to alcohol, all groups and group VI excluded PTA Alcohol Alcohol taken No alcohol
All groups < 60 min > 60 min 6 32
11 17
Group VI excluded < 60 min > 60 min 5 32
11 13
All groupsX* = 4.69, P < 0.05. Group VI excluded,X* = 7.84, P~0.01.
only within quite wide limits. This resulted from the uncertainty ofthe exact time of the accident and from the difftculty of relating the patient’s return of memory to known events. The groupings of ‘less than 5 minutes’, ‘between 5 and 30 minutes’, and ‘more than 30 and less than 60 minutes’ were as precise as could be achieved (Gronwall and Wrightson, 1980). The length of PTA between 1 and 6 hours could be estimated within about half an hour, and within an hour or more for durations over this. The distribution of PTA is shown in Table I. It was uniform in each of groups I-V, but the proportion of PTA over 3 hours was greater in
stated
group VI, whose members had been admitted to hospital (P = 0.003). PTA was significantly longer in road traffic accidents (P ~0.01); the difference diminished but remained statistically significant (P=O.O4) when cases affected by alcohol were excluded (Table If). There was a higher proportion of longer PTA in those who had taken alcohol (P~0.05); the effect was more marked when only groups I-V were considered (PC 0.0 1) (Table III). Time off work showed no statistically signiftcant dependance on PTA in groups I-V, with or without alcohol (Tabfe ZV”).Patients in group VI were off work longer (see later).
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Tab/e/V. Relation of time off work to PTA, with and without alcohol, groups I-V only Full sample
Excluding alcohol
Mean PTA (mins)
days off
5<:9 30-60
2.73 3.41 3.00
>60 ~60
5.06 3.07
O-l
8 14
Days off (no. of patients) 2-6 7+ Total
9 17
7’ 6”
Mean days Off
15 16 6
2.36 2.04 3.00
24 37
3.65 2.30
o-1
Days off (no. of patients) 2-6 7+ Total 14 14 4
4 14
6 15
3t 3t
13 32
*x2 = 1.48, n.s.d. tx* = 1.70, n.s.d.
Table V. Relation of time off work to age and alcohol, all groups
Age (years) 17-21 22-29 30-39 40-48’
Full sample Mean TOW Number (days) 32 22 8 4
Alcohol excluded Mean TOW Number (days)
4.3 3.6 4.3 17.3
26 18 4 1
4.2 3.7 3.8 3.0
‘No cases in group VI.
Management
groups I-IV the means of time off work were 4.2, 3.6, 2.9 and 4.5 days, no difference being statistically significant. For group V, mean time was 4.4 days, in the same range. Groups I-IV were therefore uniform in respect to time off work, and the counselling and psychometric testing in group V did not affirmatively affect return to work. For group VI, time off work was 14.4 days. Because of the differences of treatment, PTA and time off work, data from this group have been treated separately, in succeeding paragraphs. In
work for only 3 days. For further analysis, patients of groups I-V were divided into those under 35 and those 35 and over, and into those with PTA of 60 minutes or less, and over 60 minutes. Within the longer PTA group, time off work increased with age; the change diminished but remained statistically significant (P ~0.1) when patients who had taken alcohol were excluded. In the shorter PTA group the relation was similar (P
Activity
Age In the three age groups within the age-range 17-39 years there was no statistically significant difference in the mean time off work, either in the full sample or when alcohol, or group VI patients, or both, were excluded (Tables V and VI). Of the 4 patients over 40, the 3 who had been drinking were off work for notably longer; the fourth, who had not been drinking, was off
when injured
Thirty-eight patients were injured while partaking in sport, 18 in road traffic accidents and 10 in other ways. Mean times off work were respectively 2.3, 7.1 and 4.7 days. When group VI cases were excluded, there was a statistically significant difference between times off work for sport and road traffic accidents (PC 0.0 1) ( Tab/e VII). The significance is lost when those who had taken alcohol are excluded.
449
Wrightson and Gronwall: Minor Head Injury
Tab/e V/. Relation of time off work to age, PTA and alcohol, groups I-V only
PTA (mins)
Full sample Mean TOW Number days
Age
660
<35 >35 <35 235
>60
33 4 20 4
2.9’ 7.8’ 3.2% 14.5+
Alcohol excluded Mean TOW Number days 30 2 12 1
2.8t 2.0t 3.05 11 .O§
*t=2.85,P<0.01.
tr= 0.45, n.s.d. $t=4.19.P
Table VII. Relation groups I-V only
A c tivity Sport Road traffic Other
of time off work to activity at accident
Full sample Mean TOW Number days
and alcohol,
Alcohol excluded Mean TOW Number days
36
2.8’
36
15 10
6.9’ 4.3
5 4
2.8t 4.3t 3.0
*t=2.90,P<0.01. tt= 1.22, n.s.d.
Responsibility
for return to work
Of the 52 patients in groups I-IV, who were in minimal contact with the investigators, 39 (75 per cent) returned to work on their own decision in a mean time of 2.3 days (range O-25 days). Nine consulted their family doctor (mean time off work 9.9 days, range 3-24 days) and 2 a hospital doctor (mean time off work 5.0 days, range O-10 days); 1 patient did not answer the question. Only 2 who saw their family doctors were off work long enough to claim compensation; they were both over 40 and were off work for 23 and 24 days. In group V, 2 made their own decision to return to work, 1 saw his family doctor and the others were advised by us. The mean time off work was 4.4 days, range l-8 days. The 5 patients of group VI were advised by us, returning in a mean time of 14.4 days, range 9-26 days. Occupation
Occupations
andsalary
were
classified
as professional,
white collar, skilled and unskilled; salaries as taking home less than $90 a week, more than $120, or in between. These classifications each divided the sample into approximately equal groups, except for the professional class, which contained only 4 patients. There were no statistically significant differences in times off work.
Alcohol
When first seen, 18 of 66 patients showed clinical evidence of having taken alcohol, graded as ‘marked’ in 14 and ‘mild’ in 4. All had been injured in activities other than sport, and the proportion among these patients was therefore higher (18 of 29, 62 per cent). In those who had taken alcohol, the proportion who were off work for more than a week was notably higher (P~0.05) (Table VIII); if only groups I-V are considered, the difference is more striking (P = 0.008).
Injury: the British Journal of Accident Surgery Vol. 1 ~/NO. 6
450
Table VIII. Relation groups I-V only
of time off work and alcohol,
Time off work (days) O-6 7+ Without alcohol With alcohol
P= a.008
Condition
40 9
Questions
Symptom groups’ (no. of patients) 1 2 3 4 5 6
Total
5
45
7
16
(exact probability).
on return
Table/X. Relation of symptoms to questions asked
to work
At the follow-up interviews patients were asked: ‘How did it feel when you got back to work?‘, ‘Could you do the job as well as usual?, ‘What stopped you?‘, ‘When did you get back to normal?. They were then asked: ‘What do you usually do when you get back from work?, ‘Did you feel like doing this?‘, ‘What stopped you?‘, and ‘How long was it before you were back to usual?‘. The questions were asked in the same way each time, using these colloquial phrases, and intending that the questions should be openended and the answers free. The wording of the answers was recorded. Under these conditions the descriptions of symptoms fell into four well defined groups: 1. A feeling of being different from usual, described as strangeness, unreality, being in a dream; detached, hazy, not 100 per cent, ‘As if I had only just been told what to do’. 2. A recognition of impaired performance, being slow, bad memory, poor concentration, inability to make a decision or solve a problem. 3. Fatigue, tired, irritable, sensitive to noise. 4. Localized symptoms, headache, diplopia, photophobia, impaired balance. Two further groups of answers were noted in connection with leisure activities: 5. A fear of the consequences of further injury, of bringing on symptoms; taking precautions. 6. The effect of other minor injuries. Of 63 patients questioned 90 days after the accident, 38 (60 per cent) had symptoms when they first returned to work. Twenty-nine (46 per cent) said that they were unable to do their work as well as usual. Of these, 20 (32 per cent) were able to work normally 14 days or less after return (mean 7.3 days), 7 in 15-30 days, 1 after 40 days and 1 was still affected at 90 days. The mean time for all 29 was 14 days.
Feelings on return to work Factors affecting work Factors affecting leisure
17t
8
6
7
0
0
2(l)
19+
4
2
1
0
1
1
265
5(3)
5
2
*For identification of symptom groups, see text. tQ = 24.00, P< 0.00 1. ~0=27.44,P
Forty (63 per cent) patients did not continue their normal leisure pattern. Thirty-eight were back to normal in 30 days or less (mean 11.5 days) and, as before, 1 was not normal until after 40 days and 1 was still affected at 90 days. Table IX shows the distribution of the answers in the six symptom groups. One answer was most common in each case; in group 1 symptoms on return to work, in group 2 in reasons for being unable to do as well as usual at work, and in group 3 in relation to leisure activities. In each case the predominance is statistically highly significant (Cochrane Q test, Q = 24.00-23.44, P-c O-00 1). Fatigue was also indicated by the times at which patients went to bed. Thirty-three (52 per cent) said that they had gone to bed early for a time. Twenty-eight were specific, the mean time ofgoing to bed being 100 minutes earlier, range 30-180 minutes, and the mean duration 16 days after the accident, range 3-90 days. There was a statistically highly significant cotnelation between those who were unable to do their job as well as usual and those who went to bed early (contingency coefficient c=o.49, P
Wrightson and Gronwall: Minor Head Injury
451
were off work for a shorter time. The difference is statistically significant Qz = 4.739, P
persisting
at
90
days
and
2
Thirteen patients (20 per cent) still had symptoms 90 days after the accident. Using the classification given in the previous section, the primary symptoms in 10 cases were in group 2, principally defects of memory and concentration and of coping with difftculties at work. In 3 cases the dominant symptoms were of group 3, of fatigue and irritability. As a secondary symptom, headache was mentioned by 2, photophobia by 3, and dizziness by 1. None complained of anxiety and none suffered from insomnia. Though all these patients were back at work, they found their capacity for this and other activities impaired to some degree. The persistence of symptoms showed no correlation with age, PTA or other factors. Five had taken alcohol at the time of the accident; symptoms occurred in 28 per cent of those associattiu with alcohol and in 17 per cent of others; the difference is not statistically significant. At 2 years only 8 of the 13 patients with symptoms at 90 days could be traced. Four still had mild symptoms of the same nature as before, and all complained of impairment of memory. Two of these, aged 39 and 47, thought that the change might be due to age. The other 2, aged 20 and 22, also complained of feeling more tired and irritable than they felt was normal. One of these had had difficulty in coping with his work, but had recently been able to start back at night school. Of the 4 who did not admit to continuing symptoms, one said that he had returned to normal about 6 months after the accident. Two did not recall the difftculties and symptoms that they had admitted freely at 3 months. Both had complained of definite impairment of memory and one had had difficulty at work and had found himself notably slower at reading. The fourth, aged 25, had not complained about either memory or concentration at 90 days, though he said that his colleagues at work called him ‘paperhead’. His wife had said
at this time that his memory was impaired fohowing this and previous bouts of concussion. He had, however, thought it wise to give up football; he also said that his tolerance of alcohol had remained reduced since the previous accident. Of the 11 matched controls, one, an engineering student aged 22, said that he had ‘a horrible memory’, but did not attribute it to the accident. One said that his memory had been poor for a considerable time after the accident but was normal now. He had described his defective memory at the 90 day interview, but had then said that it had lasted for only 2 weeks. The others made no comments. DISCUSSION
The main points for comment are the limitations of PTA as an index of the severity of a minor head injury, the shortness of the time off work after such injuries, and the high incidence of symptoms on return to work and later. The effects of age and alcohol are important. Some recommendations can be made about management. The way in which patients were selected for study was expected to provide cases of a range of severity which could be graded by the length of PTA, to which the time off work and the incidence and duration of symptoms could then be related. The results were unexpected. It proved possible to define PTA of less than an hour only within quite wide limits in spite of careful suggesting that some previous questioning, authors have specified it with unrealistic precision. Then, even when satisfactory estimates had been made, PTA did not correlate with time off work or with the incidence of symptoms. This paradox has in fact been evident in previous work, though there has been little comment on it. Steadman and Graham (1970) reported no noteworthy difference in time off work between groups classified by PTA in the range O-24 hours. Relander et al. (1972) gave time off work for patients with PTA up to 10 minutes as 26.4 days, and from 10 minutes to 24 hours as 23.9 days. Lidvall et al. (1974) showed no statistically significant difference in time off work between patients in their injury groups 2,3 and 4, a grading depending on PTA. Rutherford et al. (1977) who appear to be the first to discuss this point, found that the incidence of symptoms persisting at 6 weeks was independent of PTA, though they did not refer to the length of time off work. Other measures of the severity of the injury
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which could be used are the duration of unconsciousness or of disorientation, but they require skilled observation in the acute stage, when it is rarely available with minor injuries and cannot be determined retrospectively, as PTA can be (Gronwall and Wrightson, 1980). The only factors in this study which did relate to the time off work were the nature of the accident, the patient’s age and whether he had taken alcohol; it may be more practical to rely on these for prognosis than on the patient’s response to injury in the acute stage. The mean time off work for those injured at sport (2.8 days), or indeed for the whole sample (4.7 days), is remarkably short. A comparable series is that reported by Cook (1969). Of 490 minor head injuries at football, only 7.8 per cent were admitted to hospital. When PTA was 60 minutes or less, the mean time off work was 0.7 days; with PTA of l-24 hours it was 3 days, 90 per cent being back to work in a week. The mean time off work for the small group admitted to hospital was 14.4 days; the PTA was significantly longer, from l-24 hours. There are reports of several comparable groups of patients admitted to hospital as a precaution or for special study. Steadman and Graham (1970) for an unselected population (two thirds of whom were under the age of 50), gave a median time off work between 13 and 19 days, and Relander et al. (1972) a mean time of 25 days, all for patients with a PTA of less than 24 hours. Lidvall et al. (I 974) gave a mean time off work of 23 days for male patients aged 17 to 39 who had some postconcussion symptoms, a group comparable to the present one. Cook (1972), for a group under 50 and 76 per cent male, gave a mean time off work of 24 days for those without compensation claims, and of 88 days for those with such claims. Only a rough comparison can be made between these groups and those of patients not admitted; this is because of variations in age, social conditions and criteria for admission, as well as reservations about the value of PTA in classifying injuries of this sort. There is, however, the strong impression that for comparable injuries the admission of patients to hospital leads to a longer time off work. Although the time of return to work may be a useful index of the severity of the injury, and itself of economic importance, it is evident that it does not indicate recovery. If, as in most of the cases reported here, the patient decides for himself to return, it is because he feels well enough at home. If he asks for a medical certificate, it is likely to be given because this is what
he tells the doctor, not because his performance has been observed and the needs of his work assessed. If he has been in hospital, a longer period of recovery will be expected. In one case return to work may be earlier than desirable, in the other later than necessary. Time off work was plainly related to taking alcohol. However, its close association with road traffic accidents makes it impossible to say whether drinking people are involved in more violent accidents, or take longer to recover, or both. Observations on more cases might settle this point. Age is accepted as an important factor in the recovery from minor head injury and it is notable that the effect appeared to begin .to operate as early as the 35th year of age. It was more marked when PTA was longer, and also if alcohol had been taken, suggesting that the effect ofeach factor can be additive. The most striking features were the high incidence of symptoms on return to work, and their nature. About half the patients described unpleasant symptoms. The majority had lost them by 3 weeks, but one fifth of the whole group still had symptoms 13 weeks after the accident, and in some they were still present after 2 years. A similar incidence of symptoms has been reported in previous series (Rutherford et al., 1979; Cook, 1972), but in these the patients had ofien complained of disability or had sought compensation. The importance of the present observations is that none of the patients had made formal complaints about symptoms, and none had outstanding claims for compensation. The symptoms which are common on return to work can therefore persist when there is nothing obvious to gain from them. Had the symptoms been worse, or had the patients not been selected from the most robust section of the community, medical advice might have been sought. If at the same time there had been growing anxiety and perhaps a sense of grievance, all the classical features of the post-concussion syndrome would have been recognised. The description of symptoms on return to work was remarkably uniform, though the way in which the patients were questioned about their key activities may have limited the number of possible answers. However, the tendency to give positive answers either to none of the questions or to most of them, and the association of such symptoms as retiring early to bed and being unable to do the job as well as usual, suggest that most of the effects are due to a eeneral imnairment of function rather than to
Wrightson and Gronwall: Minor Head Injury
separate and individual defects. Such an impairment could be expected to be related to the rate at which information can be processed by the brain, which has been shown to be reduced after minor head injury (Gronwall and Wrightson, 1974). Return ofthe rate to within normal limits is usually complete within 2 1 days, a time which agrees well with the observed duration of symptoms in the majority of cases. Again, symptoms are more common in patients who return to work early, suggesting that they may occur when too much is asked of a reduced capacity. For the persistence of symptoms to 90 days and 2 years there is as yet no such explanation in experimental findings. In this series no psychometric tests were carried out on the patients who had persisting symptoms, but experience with comparable groups suggests that they would at this stage have been within normal limits (Gronwall and Wrightson, 1974). However, there may be a deficit which the available tests do not reveal; there is evidence for this in the greater disturbance of function which follows a second concussion (Gronwall and Wrightson, 1975) and in the changes of response which occur when patients who have recovered from minor head injuries are subjected to mild hypoxia (Ewing et al., 1980). It is, of course, possible that in these patients there was a psychogenic component to their persisting symptoms, but for several reasons it is unlikely. As mentioned above, they were robust young men with nothing to gain, they had made no complaint and their symptoms had been present since the first examination. There was no indication in the symptoms volunteered that they were under stress, and in particular there were no complaints of anxiety or insomnia, though some said they were irritable. Headache was rare, though in other series it has been frequent and associated with anxiety (Rutherford et al., 1979). It is with the possible development in susceptible patients of such a psychogenic component that the management of minor head injury must be principally concerned, for there is no indication as yet that the organic deficit can be reduced by anything other than natural recovery. For such patients explanation and support will be necessary if they are to understand and tolerate the early symptoms without excessive anxiety. If the symptoms fail to clear soon, a formal programme of regular treatment will be necessary. lndividual counselling should be given, and group sessions with patients who have passed
453
through this stage and are recovering are valuable. Physical and mental exercise graded to the patient’s capacity will help him to cope with his condition as he recovers. It is plainly important that the patient and his relatives should have the effects of concussion and the likely course of recovery explained to them as soon as possible. When the patient is sent home after a few hours of observation, he is unlikely to be very receptive, and a definite arrangement should be made for him to be reviewed in 2 or 3 days. This is often unsatisfactory, however, and admission to hospital, even for 24 hours, has many advantages. The subject of early detection of developing intracranial haematoma and other acute complications is outside the scope of this discussion. Admission, however, gives time to examine the patient more completely, particularly for cranial nerve lesions, such as anosmia, damage to the middle and inner ears, and cerebrospinal fluid leaks, all of which can be overlooked in a busy accident department. Medical staff and occupational therapists can be given enough time to discuss the symptoms of concussion and how to cope with them. The demands of the patient’s work can be assessed and he can be advised when to return. The disadvantage of admission to hospital is its cost, and the longer period off work which usually follows. The latter may in fact be helpful, as patients who are off work longer tend to have fewer symptoms on return. A doctor who has experience in head injury management and knows the patient’s work and his capacity, should be able to determine the best time to return. Some patients, particularly young men with slight injuries, may be unwilling to stay in hospital, and provided that none of the factors associated with acute complications are present, it is acceptable for them to be allowed home. Adequate arrangements must, however, be made for them to return in 2 or 3 days for clinical review and counselling. Whether or not the patient has been admitted to hospital, he should be seen again after 2 weeks. Clinical examination, and, if indicated. psychometric testing, should then detect those who are at risk and need help, and direct them to a rehabilitation programme. Unfortunately, though an ideal service can be planned in this way, it may be difficult to establish. In the short term it may appear too expensive, and clinic visits may be unacceptable to patients after what appears to be a trivial injury. It may be argued that the opportunity to complain may be too tempting to the neurotic and the malingerer.
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With experience of such a system, however, the authors believe that it is easier to recognise and deal with such patients early, in the context of rehabilitation, than later, in that of the psychiatric clinic or the law courts. Acknowledgements
Miss Margaret McBride carried out the followup interviews; without her skill and tact the investigation would have been impossible. The Medical Superintendents of Auckland and Green Lane Hospitals and the medical and nursing staff of the Accident and Emergency Departments of these hospitals are thanked for their generous cooperation. The investigation was supported by the Medical Research Council of New Zealand and by the Accident Compensation Commission, REFERENCES
Cook J. B. (1969) The effect of minor head injuries sustained in sport and the post-concussional syndrome. In: Walker A. E., Caveness W. F. and Critchley M. (eds) The Late Effects of Head Injury. Springfield, Charles C. Thomas, pp. 408-4 13. Cook J. B. (1972) The post-concussional syndrome and factors influencing recovery after minor head iniurv admitted to hospital. &and. J. Rehabil. Med. 4;27: Ewing R., McCarthy D., Gronwall D. et al. (1981) Persisting effects of concussion shown by impaired
Requesfsfor
reprints should be addressed to: Dr P. Wrightson,
Auckland, New Zealand.
performance at altitude. J. Clin. Neuropsychol. 2,
147. Field J. H. (1976) A Study of the Epidemiology of Head Injury in England and Wales, withParticular Applicaiion to Rehabilitation. London, HMSO. Gronwall D. and Wriehtson P. (1974) Delaved recovery after minor head injury. L&cet i, 605. ’ Gronwall D. and Wrightson P. (1975) Cumulative effect ofconcussion. Lancet 2,995. Gronwall D. and Wrightson P. (1980) Duration of post-traumatic amnesia alter mild head injury. J. Clin. Neuropsychol. 2,5 I. Jennett B., Murray A., McMillan R. et al. (1977) Head injuries in Scottish hospitals. Lancet 2,696. Lidvall H. F., Linderoth B. and Norlin B. (1974) Causes of the post-concussional syndrome. Acta Neural. Stand. 50, Suppl. 56. Muller G. E. (1969) Early clinical history, EEG controls, and social outcome in 1925 head injury patients. In: Walker A. E., Caveness W. F. and Critchley M. (eds) The Late Effects ofHead Injury. Springfield, Charles C. Thomas, pp. 4 14-422 Relander M., Troupp M. and Bjorkesten G. (1972) Controlled trial of treatment for cerebral concussion. Br. Med. J. 4,777. Rutherford W. H., Merrett J. D. and McDonald J. R. The sequelae of concussion caused by minor head injuries (1977) Lancet 1, 1. Rutherford W. J., Merrett J. D. and McDonald J. R. (1979) Symptoms at one year following concussion from minor head injuries. Injury 10,225. Steadman J. H. and Graham J. G. (1970) Head injuries: an analysis and follow up study. Proc. R. Sot. Med. 63,23.
Department
of Neurosurgery,
Auckland Hospital, Private Bag,
Printedin
GreatBritain
445
Time off work and symptoms head injury Philip Wrightson Department
after minor
and Dorothy Gronwall
of Neurosurgery, Auckland Hospital, NewZealand
Summary
A carefully controlled prospective study was made of 66 men aged 17 to 48 with minor head injuries. The mean time off work was 4.7 days, range 0 to 26 days. Time off work was longer: in older patients; after road trafftc accidents compared with sports injuries; in patients who had taken alcohol and in 5 patients who had needed admission to hospital. Post-traumatic amnesia alone did not relate to time off work but was longer in these groups of patients. Sixty per cent of patients had symptoms on return to work and 46 per cent could not do their job as well as usual for a mean time of 14 days. Leisure activities were affected for a similar period and fatigue was common. Ninety days after the accident 20 per cent still had symptoms, mostly defects of memory, concentration and work capacity. Four patients still had symptoms 2 years later. Though describing symptoms, all patients were back at their usual work and none had any claim for compensation outstanding. Major points emerging are the limitations of posttraumatic amnesia as an index of the severity of a minor head injury, and the high incidence of symptoms on return to work and later, in patients who were at work and without compensation claims. The importance is stressed of an effective programme for the management of minor head injuries. INTRODUCTION MINOR head injuries economic importance.
are
of great
social
and
Not only does their care in the acute stages load the hospital services
industry (Cook, 1969; Muller, 1969; Cook, 1972), and when compensation is involved (Muller, 1969; Cook, 1972), and there is doubt about the relation of persisting symptoms to organic causes (Rutherford et al., 1979). It is plain that if minor head injury is to be managed efficiently, these uncertainties must be resolved. Although for this to be done the natural history of the injury must be known, the information available is mostly unsatisfactory. Much of it has been gathered retrospectively, samples have been unrepresentative and many factors have been uncontrolled. The recent studies of Rutherford et al. (1977; 1979) have avoided many ofthese difficulties, but the results have been partly obscured by the diversity of their patients and by the influence of compensation. This prospective study has tried to avoid these uncertainties by looking at minor head injury when recovery occurs under the simplest conditions. The sample is limited to young employed men. Post-traumatic amnesia, conventionally an important measure of the severity of injury, was determined with great care and precautions were taken to avoid suggesting symptoms to patients. Lastly, the nature of the sample, the mildness of the injury and the structure of New Zealand accident compensation law allowed the results to be relatively unaffected by considerations of compensation.
(Field, 1976) but persisting symptoms lead to disability and litigation (Rutherford et al., 1979). There is still difference of opinion on policies of acute care (Jennett et al., 1977), and provision for later management is rare. There are large differences in the period of disability
PATIENTS AND METHODS Sixty-six New Zealand men in regular
reported aRer comparable
ment aged 17-48,
injuries
in sport and
employwere studied. They had been
446
Injury: the British Journal of Accident Surgery Vol. 1 ~/NO. 6
brought to the Accident and Emergency Department of Auckland or Green Lane Hospital from 1600 to 2400 hours with a diagnosis of minor head injury. They were seen within 2 hours of the accident by one of us and included in the study if they were fit to return home after observation and if they had no other injury which would affect their return to work. Routine observations included serial tests of orientation, retrograde and post-traumatic amnesia (PTA), and also of recent memory. From the history and from the smell of alcohol in the breath or vomitus an estimate was made of whether the patient had taken alcohol before the accident; for medicolegal and ethical reasons blood was not taken for ethanol estimation. Details of the accident and of the patient’s age, employment and wages were noted. Patients were allotted to five groups for follow-up. The groups were balanced for age, occupation and the distribution of PTA duration. All were interviewed 90 days alter injury, and in addition those in groups I, II and III were seen at 7, 14 and 30 days respectively. Patients in group V were brought back to hospital again within 48 hours, given psychometric tests and counselled about the effects of concussion. The tests were repeated each week until the results had returned to normal. A sixth group was formed from patients who had been examined in the same way but who needed admission to hospital. They were followed up in the same way as group V patients. The patients were seen at the 90th day after the accident, as well as before then, by an occupational therapist who was experienced in the treatment of head injuries, and used the same questionnaire each time; this covered the following: 1. Memory for events before and alter the accident, to give estimates of retrograde and post-traumatic amnesia. For the present purpose, the end of PTA was taken to be the return of continuous memory. 2. The date of return to work, who had authorized this, and details of accident compensation. 3. How patients felt when they returned to work, whether they could do the job as well as usual, and ifnot, why. 4. What they usually did after work, and whether there had been any change in leisure activities or in the time at which they had gone to bed. 5. Symptoms. An open-ended question about any trouble since the accident was followed by
specific questions about 12 common symptoms -headache, photophobia, diplopia, tinnitus, dizziness, to noise, sensitivity deafness, tiredness, irritability, memory, concentration and difficulties at work. The interviews were all carried out in the patient’s home and were made as friendly and informal as possible, showing proper concern but not encouraging patients to dwell on symptoms. Family and friends were often present, and their comments were also recorded. This approach was well accepted, and only one patient refused to be seen a second time. The patients who were found to have persisting symptoms at 90 days were sought 2 years after the accideti. Only two-thirds were traced. They were interviewed again, using the same questionnaire, together with a sample of patients who had been free from symptoms, matched for age, occupation and cause of injury. These interviews were carried out by one of us (D.G.). RESULTS Time off work
In 66 patients the mean interval between the accident and return to work (time off work, TOW) was 4.7 days. If Sundays and holidays were excluded, the mean number of working days lost was 3.3 days. Fifty-four patients (81.8 per cent) returned to work between 0 and 7 days, 7 (10.6 per cent) between 8 and 14 days, and 5 (7.6 per cent) between 15 and 30 days after the injury was incurred. Accident
compensation
Only 3 of the 66 patients were injured at work. Two lost no working days, and 1 lost 2 working days. (Note: under New Zealand law, those unable to work because of an accident at work are paid by their employer for the first week of their disability. After 1 week, those unable to work because of an accident, however sustained, are paid compensation related to their earnings, irrespective of fault.) Of the 7 patients off work between 8 and 14 days who were eligible for compensation, only 2 applied for it; the 5 who were off work between 15 and 30 days all received compensation. Factors related to time off work Post-traumatic amnesia
The record of each patient contained key times and events following the accident, observed by others up to arrival at hospital and subsequently by one of us. However, even with these records, it was found that PTA of short duration could be
447
Wrightson and Gronwall: Minor Head Injury Table /. Distribution of PTA durations
Groups I-V VI
o-1 37 1
l-3
3-6
16 0
6 1
PTA (hours) 6-9
9-18
1 1
18-36
1 0
0 2
Total 61 5
Tab/e //. Relation of PTA to activity, all groups PTA Activity Road traffic Sport Other
Excluding alcohol < 60 min > 60 min
Full sample > 60 min < 60 min 4 25 9
14 12 2
2 25 5
5 12 0
RTA v. sport: full sampleX2 = 10.02, P ~0.01, excluding alcohol P= 0.06. Other v. sport: full sample P= 0.2 1, excluding alcohol P= 0.17. RTA v. other: full sample P= 0.002, excluding alcohol P= 0.03. (Exact probabilities).
Tab/e///. Relation of PTA to alcohol, all groups and group VI excluded PTA Alcohol Alcohol taken No alcohol
All groups < 60 min > 60 min 6 32
11 17
Group VI excluded < 60 min > 60 min 5 32
11 13
All groupsX* = 4.69, P < 0.05. Group VI excluded,X* = 7.84, P~0.01.
only within quite wide limits. This resulted from the uncertainty ofthe exact time of the accident and from the difftculty of relating the patient’s return of memory to known events. The groupings of ‘less than 5 minutes’, ‘between 5 and 30 minutes’, and ‘more than 30 and less than 60 minutes’ were as precise as could be achieved (Gronwall and Wrightson, 1980). The length of PTA between 1 and 6 hours could be estimated within about half an hour, and within an hour or more for durations over this. The distribution of PTA is shown in Table I. It was uniform in each of groups I-V, but the proportion of PTA over 3 hours was greater in
stated
group VI, whose members had been admitted to hospital (P = 0.003). PTA was significantly longer in road traffic accidents (P ~0.01); the difference diminished but remained statistically significant (P=O.O4) when cases affected by alcohol were excluded (Table If). There was a higher proportion of longer PTA in those who had taken alcohol (P~0.05); the effect was more marked when only groups I-V were considered (PC 0.0 1) (Table III). Time off work showed no statistically signiftcant dependance on PTA in groups I-V, with or without alcohol (Tabfe ZV”).Patients in group VI were off work longer (see later).
44%
Injury: the British Journal of Accident Surgery Vol. 1 ~/NO. 6
Tab/e/V. Relation of time off work to PTA, with and without alcohol, groups I-V only Full sample
Excluding alcohol
Mean PTA (mins)
days off
5<:9 30-60
2.73 3.41 3.00
>60 ~60
5.06 3.07
O-l
8 14
Days off (no. of patients) 2-6 7+ Total
9 17
7’ 6”
Mean days Off
15 16 6
2.36 2.04 3.00
24 37
3.65 2.30
o-1
Days off (no. of patients) 2-6 7+ Total 14 14 4
4 14
6 15
3t 3t
13 32
*x2 = 1.48, n.s.d. tx* = 1.70, n.s.d.
Table V. Relation of time off work to age and alcohol, all groups
Age (years) 17-21 22-29 30-39 40-48’
Full sample Mean TOW Number (days) 32 22 8 4
Alcohol excluded Mean TOW Number (days)
4.3 3.6 4.3 17.3
26 18 4 1
4.2 3.7 3.8 3.0
‘No cases in group VI.
Management
groups I-IV the means of time off work were 4.2, 3.6, 2.9 and 4.5 days, no difference being statistically significant. For group V, mean time was 4.4 days, in the same range. Groups I-IV were therefore uniform in respect to time off work, and the counselling and psychometric testing in group V did not affirmatively affect return to work. For group VI, time off work was 14.4 days. Because of the differences of treatment, PTA and time off work, data from this group have been treated separately, in succeeding paragraphs. In
work for only 3 days. For further analysis, patients of groups I-V were divided into those under 35 and those 35 and over, and into those with PTA of 60 minutes or less, and over 60 minutes. Within the longer PTA group, time off work increased with age; the change diminished but remained statistically significant (P ~0.1) when patients who had taken alcohol were excluded. In the shorter PTA group the relation was similar (P
Activity
Age In the three age groups within the age-range 17-39 years there was no statistically significant difference in the mean time off work, either in the full sample or when alcohol, or group VI patients, or both, were excluded (Tables V and VI). Of the 4 patients over 40, the 3 who had been drinking were off work for notably longer; the fourth, who had not been drinking, was off
when injured
Thirty-eight patients were injured while partaking in sport, 18 in road traffic accidents and 10 in other ways. Mean times off work were respectively 2.3, 7.1 and 4.7 days. When group VI cases were excluded, there was a statistically significant difference between times off work for sport and road traffic accidents (PC 0.0 1) ( Tab/e VII). The significance is lost when those who had taken alcohol are excluded.
449
Wrightson and Gronwall: Minor Head Injury
Tab/e V/. Relation of time off work to age, PTA and alcohol, groups I-V only
PTA (mins)
Full sample Mean TOW Number days
Age
660
<35 >35 <35 235
>60
33 4 20 4
2.9’ 7.8’ 3.2% 14.5+
Alcohol excluded Mean TOW Number days 30 2 12 1
2.8t 2.0t 3.05 11 .O§
*t=2.85,P<0.01.
tr= 0.45, n.s.d. $t=4.19.P
Table VII. Relation groups I-V only
A c tivity Sport Road traffic Other
of time off work to activity at accident
Full sample Mean TOW Number days
and alcohol,
Alcohol excluded Mean TOW Number days
36
2.8’
36
15 10
6.9’ 4.3
5 4
2.8t 4.3t 3.0
*t=2.90,P<0.01. tt= 1.22, n.s.d.
Responsibility
for return to work
Of the 52 patients in groups I-IV, who were in minimal contact with the investigators, 39 (75 per cent) returned to work on their own decision in a mean time of 2.3 days (range O-25 days). Nine consulted their family doctor (mean time off work 9.9 days, range 3-24 days) and 2 a hospital doctor (mean time off work 5.0 days, range O-10 days); 1 patient did not answer the question. Only 2 who saw their family doctors were off work long enough to claim compensation; they were both over 40 and were off work for 23 and 24 days. In group V, 2 made their own decision to return to work, 1 saw his family doctor and the others were advised by us. The mean time off work was 4.4 days, range l-8 days. The 5 patients of group VI were advised by us, returning in a mean time of 14.4 days, range 9-26 days. Occupation
Occupations
andsalary
were
classified
as professional,
white collar, skilled and unskilled; salaries as taking home less than $90 a week, more than $120, or in between. These classifications each divided the sample into approximately equal groups, except for the professional class, which contained only 4 patients. There were no statistically significant differences in times off work.
Alcohol
When first seen, 18 of 66 patients showed clinical evidence of having taken alcohol, graded as ‘marked’ in 14 and ‘mild’ in 4. All had been injured in activities other than sport, and the proportion among these patients was therefore higher (18 of 29, 62 per cent). In those who had taken alcohol, the proportion who were off work for more than a week was notably higher (P~0.05) (Table VIII); if only groups I-V are considered, the difference is more striking (P = 0.008).
Injury: the British Journal of Accident Surgery Vol. 1 ~/NO. 6
450
Table VIII. Relation groups I-V only
of time off work and alcohol,
Time off work (days) O-6 7+ Without alcohol With alcohol
P= a.008
Condition
40 9
Questions
Symptom groups’ (no. of patients) 1 2 3 4 5 6
Total
5
45
7
16
(exact probability).
on return
Table/X. Relation of symptoms to questions asked
to work
At the follow-up interviews patients were asked: ‘How did it feel when you got back to work?‘, ‘Could you do the job as well as usual?, ‘What stopped you?‘, ‘When did you get back to normal?. They were then asked: ‘What do you usually do when you get back from work?, ‘Did you feel like doing this?‘, ‘What stopped you?‘, and ‘How long was it before you were back to usual?‘. The questions were asked in the same way each time, using these colloquial phrases, and intending that the questions should be openended and the answers free. The wording of the answers was recorded. Under these conditions the descriptions of symptoms fell into four well defined groups: 1. A feeling of being different from usual, described as strangeness, unreality, being in a dream; detached, hazy, not 100 per cent, ‘As if I had only just been told what to do’. 2. A recognition of impaired performance, being slow, bad memory, poor concentration, inability to make a decision or solve a problem. 3. Fatigue, tired, irritable, sensitive to noise. 4. Localized symptoms, headache, diplopia, photophobia, impaired balance. Two further groups of answers were noted in connection with leisure activities: 5. A fear of the consequences of further injury, of bringing on symptoms; taking precautions. 6. The effect of other minor injuries. Of 63 patients questioned 90 days after the accident, 38 (60 per cent) had symptoms when they first returned to work. Twenty-nine (46 per cent) said that they were unable to do their work as well as usual. Of these, 20 (32 per cent) were able to work normally 14 days or less after return (mean 7.3 days), 7 in 15-30 days, 1 after 40 days and 1 was still affected at 90 days. The mean time for all 29 was 14 days.
Feelings on return to work Factors affecting work Factors affecting leisure
17t
8
6
7
0
0
2(l)
19+
4
2
1
0
1
1
265
5(3)
5
2
*For identification of symptom groups, see text. tQ = 24.00, P< 0.00 1. ~0=27.44,P
Forty (63 per cent) patients did not continue their normal leisure pattern. Thirty-eight were back to normal in 30 days or less (mean 11.5 days) and, as before, 1 was not normal until after 40 days and 1 was still affected at 90 days. Table IX shows the distribution of the answers in the six symptom groups. One answer was most common in each case; in group 1 symptoms on return to work, in group 2 in reasons for being unable to do as well as usual at work, and in group 3 in relation to leisure activities. In each case the predominance is statistically highly significant (Cochrane Q test, Q = 24.00-23.44, P-c O-00 1). Fatigue was also indicated by the times at which patients went to bed. Thirty-three (52 per cent) said that they had gone to bed early for a time. Twenty-eight were specific, the mean time ofgoing to bed being 100 minutes earlier, range 30-180 minutes, and the mean duration 16 days after the accident, range 3-90 days. There was a statistically highly significant cotnelation between those who were unable to do their job as well as usual and those who went to bed early (contingency coefficient c=o.49, P
Wrightson and Gronwall: Minor Head Injury
451
were off work for a shorter time. The difference is statistically significant Qz = 4.739, P
persisting
at
90
days
and
2
Thirteen patients (20 per cent) still had symptoms 90 days after the accident. Using the classification given in the previous section, the primary symptoms in 10 cases were in group 2, principally defects of memory and concentration and of coping with difftculties at work. In 3 cases the dominant symptoms were of group 3, of fatigue and irritability. As a secondary symptom, headache was mentioned by 2, photophobia by 3, and dizziness by 1. None complained of anxiety and none suffered from insomnia. Though all these patients were back at work, they found their capacity for this and other activities impaired to some degree. The persistence of symptoms showed no correlation with age, PTA or other factors. Five had taken alcohol at the time of the accident; symptoms occurred in 28 per cent of those associattiu with alcohol and in 17 per cent of others; the difference is not statistically significant. At 2 years only 8 of the 13 patients with symptoms at 90 days could be traced. Four still had mild symptoms of the same nature as before, and all complained of impairment of memory. Two of these, aged 39 and 47, thought that the change might be due to age. The other 2, aged 20 and 22, also complained of feeling more tired and irritable than they felt was normal. One of these had had difficulty in coping with his work, but had recently been able to start back at night school. Of the 4 who did not admit to continuing symptoms, one said that he had returned to normal about 6 months after the accident. Two did not recall the difftculties and symptoms that they had admitted freely at 3 months. Both had complained of definite impairment of memory and one had had difficulty at work and had found himself notably slower at reading. The fourth, aged 25, had not complained about either memory or concentration at 90 days, though he said that his colleagues at work called him ‘paperhead’. His wife had said
at this time that his memory was impaired fohowing this and previous bouts of concussion. He had, however, thought it wise to give up football; he also said that his tolerance of alcohol had remained reduced since the previous accident. Of the 11 matched controls, one, an engineering student aged 22, said that he had ‘a horrible memory’, but did not attribute it to the accident. One said that his memory had been poor for a considerable time after the accident but was normal now. He had described his defective memory at the 90 day interview, but had then said that it had lasted for only 2 weeks. The others made no comments. DISCUSSION
The main points for comment are the limitations of PTA as an index of the severity of a minor head injury, the shortness of the time off work after such injuries, and the high incidence of symptoms on return to work and later. The effects of age and alcohol are important. Some recommendations can be made about management. The way in which patients were selected for study was expected to provide cases of a range of severity which could be graded by the length of PTA, to which the time off work and the incidence and duration of symptoms could then be related. The results were unexpected. It proved possible to define PTA of less than an hour only within quite wide limits in spite of careful suggesting that some previous questioning, authors have specified it with unrealistic precision. Then, even when satisfactory estimates had been made, PTA did not correlate with time off work or with the incidence of symptoms. This paradox has in fact been evident in previous work, though there has been little comment on it. Steadman and Graham (1970) reported no noteworthy difference in time off work between groups classified by PTA in the range O-24 hours. Relander et al. (1972) gave time off work for patients with PTA up to 10 minutes as 26.4 days, and from 10 minutes to 24 hours as 23.9 days. Lidvall et al. (1974) showed no statistically significant difference in time off work between patients in their injury groups 2,3 and 4, a grading depending on PTA. Rutherford et al. (1977) who appear to be the first to discuss this point, found that the incidence of symptoms persisting at 6 weeks was independent of PTA, though they did not refer to the length of time off work. Other measures of the severity of the injury
452
Injury: the British Journal of Accident Surgery Vol. 1 ~/NO. 6
which could be used are the duration of unconsciousness or of disorientation, but they require skilled observation in the acute stage, when it is rarely available with minor injuries and cannot be determined retrospectively, as PTA can be (Gronwall and Wrightson, 1980). The only factors in this study which did relate to the time off work were the nature of the accident, the patient’s age and whether he had taken alcohol; it may be more practical to rely on these for prognosis than on the patient’s response to injury in the acute stage. The mean time off work for those injured at sport (2.8 days), or indeed for the whole sample (4.7 days), is remarkably short. A comparable series is that reported by Cook (1969). Of 490 minor head injuries at football, only 7.8 per cent were admitted to hospital. When PTA was 60 minutes or less, the mean time off work was 0.7 days; with PTA of l-24 hours it was 3 days, 90 per cent being back to work in a week. The mean time off work for the small group admitted to hospital was 14.4 days; the PTA was significantly longer, from l-24 hours. There are reports of several comparable groups of patients admitted to hospital as a precaution or for special study. Steadman and Graham (1970) for an unselected population (two thirds of whom were under the age of 50), gave a median time off work between 13 and 19 days, and Relander et al. (1972) a mean time of 25 days, all for patients with a PTA of less than 24 hours. Lidvall et al. (I 974) gave a mean time off work of 23 days for male patients aged 17 to 39 who had some postconcussion symptoms, a group comparable to the present one. Cook (1972), for a group under 50 and 76 per cent male, gave a mean time off work of 24 days for those without compensation claims, and of 88 days for those with such claims. Only a rough comparison can be made between these groups and those of patients not admitted; this is because of variations in age, social conditions and criteria for admission, as well as reservations about the value of PTA in classifying injuries of this sort. There is, however, the strong impression that for comparable injuries the admission of patients to hospital leads to a longer time off work. Although the time of return to work may be a useful index of the severity of the injury, and itself of economic importance, it is evident that it does not indicate recovery. If, as in most of the cases reported here, the patient decides for himself to return, it is because he feels well enough at home. If he asks for a medical certificate, it is likely to be given because this is what
he tells the doctor, not because his performance has been observed and the needs of his work assessed. If he has been in hospital, a longer period of recovery will be expected. In one case return to work may be earlier than desirable, in the other later than necessary. Time off work was plainly related to taking alcohol. However, its close association with road traffic accidents makes it impossible to say whether drinking people are involved in more violent accidents, or take longer to recover, or both. Observations on more cases might settle this point. Age is accepted as an important factor in the recovery from minor head injury and it is notable that the effect appeared to begin .to operate as early as the 35th year of age. It was more marked when PTA was longer, and also if alcohol had been taken, suggesting that the effect ofeach factor can be additive. The most striking features were the high incidence of symptoms on return to work, and their nature. About half the patients described unpleasant symptoms. The majority had lost them by 3 weeks, but one fifth of the whole group still had symptoms 13 weeks after the accident, and in some they were still present after 2 years. A similar incidence of symptoms has been reported in previous series (Rutherford et al., 1979; Cook, 1972), but in these the patients had ofien complained of disability or had sought compensation. The importance of the present observations is that none of the patients had made formal complaints about symptoms, and none had outstanding claims for compensation. The symptoms which are common on return to work can therefore persist when there is nothing obvious to gain from them. Had the symptoms been worse, or had the patients not been selected from the most robust section of the community, medical advice might have been sought. If at the same time there had been growing anxiety and perhaps a sense of grievance, all the classical features of the post-concussion syndrome would have been recognised. The description of symptoms on return to work was remarkably uniform, though the way in which the patients were questioned about their key activities may have limited the number of possible answers. However, the tendency to give positive answers either to none of the questions or to most of them, and the association of such symptoms as retiring early to bed and being unable to do the job as well as usual, suggest that most of the effects are due to a eeneral imnairment of function rather than to
Wrightson and Gronwall: Minor Head Injury
separate and individual defects. Such an impairment could be expected to be related to the rate at which information can be processed by the brain, which has been shown to be reduced after minor head injury (Gronwall and Wrightson, 1974). Return ofthe rate to within normal limits is usually complete within 2 1 days, a time which agrees well with the observed duration of symptoms in the majority of cases. Again, symptoms are more common in patients who return to work early, suggesting that they may occur when too much is asked of a reduced capacity. For the persistence of symptoms to 90 days and 2 years there is as yet no such explanation in experimental findings. In this series no psychometric tests were carried out on the patients who had persisting symptoms, but experience with comparable groups suggests that they would at this stage have been within normal limits (Gronwall and Wrightson, 1974). However, there may be a deficit which the available tests do not reveal; there is evidence for this in the greater disturbance of function which follows a second concussion (Gronwall and Wrightson, 1975) and in the changes of response which occur when patients who have recovered from minor head injuries are subjected to mild hypoxia (Ewing et al., 1980). It is, of course, possible that in these patients there was a psychogenic component to their persisting symptoms, but for several reasons it is unlikely. As mentioned above, they were robust young men with nothing to gain, they had made no complaint and their symptoms had been present since the first examination. There was no indication in the symptoms volunteered that they were under stress, and in particular there were no complaints of anxiety or insomnia, though some said they were irritable. Headache was rare, though in other series it has been frequent and associated with anxiety (Rutherford et al., 1979). It is with the possible development in susceptible patients of such a psychogenic component that the management of minor head injury must be principally concerned, for there is no indication as yet that the organic deficit can be reduced by anything other than natural recovery. For such patients explanation and support will be necessary if they are to understand and tolerate the early symptoms without excessive anxiety. If the symptoms fail to clear soon, a formal programme of regular treatment will be necessary. lndividual counselling should be given, and group sessions with patients who have passed
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through this stage and are recovering are valuable. Physical and mental exercise graded to the patient’s capacity will help him to cope with his condition as he recovers. It is plainly important that the patient and his relatives should have the effects of concussion and the likely course of recovery explained to them as soon as possible. When the patient is sent home after a few hours of observation, he is unlikely to be very receptive, and a definite arrangement should be made for him to be reviewed in 2 or 3 days. This is often unsatisfactory, however, and admission to hospital, even for 24 hours, has many advantages. The subject of early detection of developing intracranial haematoma and other acute complications is outside the scope of this discussion. Admission, however, gives time to examine the patient more completely, particularly for cranial nerve lesions, such as anosmia, damage to the middle and inner ears, and cerebrospinal fluid leaks, all of which can be overlooked in a busy accident department. Medical staff and occupational therapists can be given enough time to discuss the symptoms of concussion and how to cope with them. The demands of the patient’s work can be assessed and he can be advised when to return. The disadvantage of admission to hospital is its cost, and the longer period off work which usually follows. The latter may in fact be helpful, as patients who are off work longer tend to have fewer symptoms on return. A doctor who has experience in head injury management and knows the patient’s work and his capacity, should be able to determine the best time to return. Some patients, particularly young men with slight injuries, may be unwilling to stay in hospital, and provided that none of the factors associated with acute complications are present, it is acceptable for them to be allowed home. Adequate arrangements must, however, be made for them to return in 2 or 3 days for clinical review and counselling. Whether or not the patient has been admitted to hospital, he should be seen again after 2 weeks. Clinical examination, and, if indicated. psychometric testing, should then detect those who are at risk and need help, and direct them to a rehabilitation programme. Unfortunately, though an ideal service can be planned in this way, it may be difficult to establish. In the short term it may appear too expensive, and clinic visits may be unacceptable to patients after what appears to be a trivial injury. It may be argued that the opportunity to complain may be too tempting to the neurotic and the malingerer.
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With experience of such a system, however, the authors believe that it is easier to recognise and deal with such patients early, in the context of rehabilitation, than later, in that of the psychiatric clinic or the law courts. Acknowledgements
Miss Margaret McBride carried out the followup interviews; without her skill and tact the investigation would have been impossible. The Medical Superintendents of Auckland and Green Lane Hospitals and the medical and nursing staff of the Accident and Emergency Departments of these hospitals are thanked for their generous cooperation. The investigation was supported by the Medical Research Council of New Zealand and by the Accident Compensation Commission, REFERENCES
Cook J. B. (1969) The effect of minor head injuries sustained in sport and the post-concussional syndrome. In: Walker A. E., Caveness W. F. and Critchley M. (eds) The Late Effects of Head Injury. Springfield, Charles C. Thomas, pp. 408-4 13. Cook J. B. (1972) The post-concussional syndrome and factors influencing recovery after minor head iniurv admitted to hospital. &and. J. Rehabil. Med. 4;27: Ewing R., McCarthy D., Gronwall D. et al. (1981) Persisting effects of concussion shown by impaired
Requesfsfor
reprints should be addressed to: Dr P. Wrightson,
Auckland, New Zealand.
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147. Field J. H. (1976) A Study of the Epidemiology of Head Injury in England and Wales, withParticular Applicaiion to Rehabilitation. London, HMSO. Gronwall D. and Wriehtson P. (1974) Delaved recovery after minor head injury. L&cet i, 605. ’ Gronwall D. and Wrightson P. (1975) Cumulative effect ofconcussion. Lancet 2,995. Gronwall D. and Wrightson P. (1980) Duration of post-traumatic amnesia alter mild head injury. J. Clin. Neuropsychol. 2,5 I. Jennett B., Murray A., McMillan R. et al. (1977) Head injuries in Scottish hospitals. Lancet 2,696. Lidvall H. F., Linderoth B. and Norlin B. (1974) Causes of the post-concussional syndrome. Acta Neural. Stand. 50, Suppl. 56. Muller G. E. (1969) Early clinical history, EEG controls, and social outcome in 1925 head injury patients. In: Walker A. E., Caveness W. F. and Critchley M. (eds) The Late Effects ofHead Injury. Springfield, Charles C. Thomas, pp. 4 14-422 Relander M., Troupp M. and Bjorkesten G. (1972) Controlled trial of treatment for cerebral concussion. Br. Med. J. 4,777. Rutherford W. H., Merrett J. D. and McDonald J. R. The sequelae of concussion caused by minor head injuries (1977) Lancet 1, 1. Rutherford W. J., Merrett J. D. and McDonald J. R. (1979) Symptoms at one year following concussion from minor head injuries. Injury 10,225. Steadman J. H. and Graham J. G. (1970) Head injuries: an analysis and follow up study. Proc. R. Sot. Med. 63,23.
Department
of Neurosurgery,
Auckland Hospital, Private Bag,