EARLY TRAUMATIC EPILEPSY

Saturday

EARLY TRAUMATIC EPILEPSY Definition and Identity W. BRYAN FROM THE DIVISION OF

JENNETT

NEUROSURGERY,

INSTITUTE OF NEUROLOGICAL

SCIENCES, GLASGOW, AND DEPARTMENT OF NEUROSURGERY, UNIVERSITY OF GLASGOW

331 patients with non-missile head injuries who had epilepsy in the first 8 weeks after injury were compared with 218 in whom epilepsy was delayed beyond 3 months. Epilepsy began in the 1st week 29 times as frequently as in any of the subsequent 7 weeks: of patients with epilepsy within 8 weeks of injury, 80·5% had their first fit in the 1st week. Localised focal motor epilepsy was common in the 1st week (40%), infrequent in the next 7 weeks (17%), and rare after that (3%). Temporal-lobe epilepsy was never recorded in the 1st week, but was as common during the next 7 weeks as it was after 3 months (20%). 1st-week epilepsy recurred or persisted in only 27% of patients, but from the 2nd week onwards the recurrence-rate was over 70%. A small missile series (73 patients) showed similar trends in regard to all the above factors. Early epilepsy has therefore distinctive characteristics which justify separate classification, but the term should be confined to fits in the 1st week after injury. Although less than a third of patients with early epilepsy have further fits in the future, this risk is significantly greater than for those without early epilepsy, which therefore has prognostic significance.

Summary

Introduction

EPILEPSY

separately by

occurring soon after injury is treated many workers, as though to imply that the

cause or the course of fits at this time may be different from epilepsy developing later. Believing it to be a manifestation of a transitory phase of cerebral dysfunction, some regard early epilepsy as of no significance for the future. Others maintain that it increases the risk of epilepsy developing later, and yet others reject the claim for special consideration of early fits. No consensus emerges about how early is early, and authors variously list separately patients having a fit in the first 1, 2, 3, or 4 weeks (table i); but none defends his choice of timeinterval, which appears to be arbitrary. Whitty (1947) suggested that earlier fits tend to occur " when widespread delayed effects of injury are at a maximum", and suggested that a physiological rather than a strictly temporal definition should be used in delineating this group of cases. In a closely observed series of 1000 consecutive blunt injuries (in Oxford) Lewin and I recorded 46 patients having the first known fit of their lives during the lst week after injury; only 1 had the first

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24

May 1969

fit between the end of the lst and the llth week (Jennett and Lewin 1960). This led us to define early epilepsy as that occurring in the 1st week after injury. Subsequent experience has yielded a small number of patients whose first fit did occur in the few weeks following the lst week, and the question arises whether these are late " early " fits, or early " late " fits; and whether the end of the 1st TABLE I-REPORTED

"

EARLY

"

EPILEPSY

week does in fact form a true watershed. It was decided therefore to study fits in the first 8 weeks after injury in some detail. Patients Studied Two series of blunt injuries were available for analysis: the original Oxford series was expanded with more cases, through the kindness of Mr. Walpole Lewin, to give 189 patients suffering epilepsy within 8 weeks of injury; and a further 150 cases were collected in Glasgow. These two series were treated separately in the early analyses as a check on the validity of the observations. The Oxford series had been studied prospectively and all patients had been observed by a neurosurgeon from the outset; it was possible therefore that more fits had been observed, especially in the early stages, than in the Glasgow series which comprised patients referred to a neurosurgical unit from a large number of general hospitals in a widely scattered region. The close correspondence between the two series was striking (table n) and strongly suggested that the phenomena observed were naturally occurring and not the result of spurious influences; in the remaining analyses these two non-missile series are considered as one. To allow some comparisons with a missile series Prof. W. Ritchie Russell TABLE II-TIME OF FIRST FIT WITHIN

8

WEEKS OF

INJURY

1024 in any one of the next 3 or the next 7 weeks (25 : 1 and 29 : 1 respectively). The rather less striking predominance of the lst week in missile injuries is clearly expressed in the corresponding figures for this series (10 :1 and 13 : 1). Relation

to

Previously Reported Series

The fact that 90% of the 1st month’s cases occur in the lst week accounts for the relatively close consistency among estimates of the frequency of early epilepsy, even when these are based on varying periods of time after injury (table I). The frequency of epilepsy during the lst week after an unselected series of blunt injuries admitted to hospital has been estimated at 5% in previous studies (Jennett 1962); the evidence of table i, together with that which has been presented in previous paragraphs, suggests that this is a fairly accurate estimate. Recurrence

of Epilepsy after Early

Seizures

Less than third of patients suffering a fit in the lst week after a non-missile injury had any further fits in the next 4 years; when the first fit occurred in the next 7 weeks, the risk of recurrence was much greater (707%), and approached that associated with epilepsy which first appears more than 3 months after injury (85-9%) (table iv). For missile injuries the risk of recurrence was also much greater after the lst week, but the difference between the lst and subsequent weeks was less striking. These observations suggest that epilepsy occurring after the lst a

TABLE IV-RECURRENCE OF EPILEPSY

"

kindly allowed me to abstract details of early " fits from his series of gunshot wounds, which had already been extensively studied for late fits (Russell and Whitty 1952); this yielded 73 cases with accurate information about the time of the first fit. All three series are made up only of patients who had their first fit within 8 weeks of injury; in all tables " week 1, 2, et seq." refers to the time of the first post-traumatic fit. Patients who suffered from established epilepsy before their injury were excluded.

Findings Time

of First Fit

In each of these series many more fits occurred in the 1st week than in any of the subsequent 7 weeks (table 11 and figure). Although in the missile series quite a few cases began in the 2nd week the difference between this and the lst week was still very striking. This predominance of the lst week can be expressed in different ways (table ill): as the percentage of patients with epilepsy within 4 or 8 weeks of injury in whom this began in the lst week (89-2% and 80-5% respectively, for non-missile injuries); or as the ratio of patients with a fit in the lst week to the average number of patients beginning epilepsy TABLE III-TIME OF FIRST FIT WITHIN

8

WEEKS OF

week more closely approximates to "late" epilepsy, because of its greater tendency to persist. Type of Fit During Early Weeks Localised focal motor attacks were common in the 1st week after injury, occurring in 41-1% of patients (table v). Epilepsy developing later rarely took this form, which occurred in only 3-2% of 218 patients whose epilepsy began more than 3 months after injury. Among these

delayed cases temporal-lobe epilepsy was quite frequent (22%), whilst this type of fit was never encountered in the

INJURY TABLE

V-TYPE

OF

EPILEPSY

AT

DIFFERENT

(NON-MISSILE)

TIMES

AFTER

INJURY

1025

ISCHÆMIC HEART-DISEASE AND WITHDRAWAL OF ANTICOAGULANT THERAPY

1st week. The type of fit encountered in patients whose epilepsy began between the 2nd and 8th week after injury more closely resembled that of epilepsy which had been delayed for more than 3 months, although focal motor seizures were rather more frequent.

V. R. KAMATH*

M. G. THORNE

FROM TORBAY HOSPITAL,

TORQUAY,

DEVON

Conclusions

Definition of Early Epilepsy

Summary

This evidence supports the view that epilepsy occurring within a week of injury is distinctly different from that occurring in the 2nd and subsequent weeks. Epilepsy is 20-30 times more frequent in the 1 st than in any subsequent week; it is much less likely to persist than is epilepsy first appearing during the next 7 weeks, which is almost as likely to persist as is epilepsy which is delayed for 3 months or more after injury. The type of seizure within the lst week is also distinctive in that focal motor attacks are very much more common whilst temporal-lobe seizures do not occur; epilepsy in the 2nd to 8th week resembles in type that appearing after 3 months. This confirms the view already expressed by Earl Walker (1957): " it is generally considered that patients having attacks within the first few weeks of a head injury usually have focal fits and that the prognosis is better than in those developing seizures later." The present study suggests, however, that such conclusions are justified only for the 1st week, and that the term " early epilepsy " should therefore be reserved for fits in the lst week after injury. TABLE VI-INFLUENCE OF EARLY EPILEPSY ON INCIDENCE OF LATE YEARS’ FOLLOW-UP) EPILEPSY (> 4

All epilepsy occurring more than a week after injury should be classified as " late ". The differences between epilepsy in the first few weeks (after the lst) and that occurring after 3 months are insufficient to justify another category to distinguish them. If a patient has epilepsy in the lst week, and subsequently suffers one or more fits in the next 7 weeks, he should be regarded as having developed both early and late epilepsy. He is likely to continue to suffer from seizures in the future, because he has already developed " late " epilepsy, even though a more favourable prognosis would have been given at the end of the 1st week, before he had had a " late " fit.

Significance of Early Epilepsy

Although many patients with early epilepsy after noninjuries developed no further seizures over the next 4 years, the proportion that did so was significantly greater than in patients who reached the end of the lst week without epilepsy (table vi). This increased risk operated to some extent whatever the other features of the injury, and early epilepsy is therefore of considerable prognostic significance. It may also be associated with intracranial haematoma or depressed fracture, and, if status epilepticus develops, life may be threatened although the primary brain damage has not been severe. These aspects of early epilepsy will be considered in detail missile

in

future communication. This study was partly supported by British Epilepsy Association.

a

References at foot of next

research grant from the

column

a

a

difference in the incidence of thromboembolic complications was found between two matched groups of 39 patients from whom long-term anticoagulants were withdrawn abruptly and gradually respectively. 37 " badrisk " patients in whom anticoagulant therapy was continued fared significantly better than either of the two " good-risk " groups from whom anticoagulants were withdrawn. In general the results suggest that withdrawal before the elapse of two years of treatment does not carry as great a risk as withdrawal after two years of treatment. Introduction THE place of long-term anticoagulant therapy in ischaemic heart-disease and the consequences of its withdrawal remain controversial. Some workers postulate the existence of a rebound state of hypercoagulability (Cosgriff 1953, Poller and Thomson 1965) or of,a period characterised by increased risk of thrombotic or thromboembolic disorders after cessation of therapy (Carter et al. 1958, Marshall 1963). Others dispute the existence of such states (Medical Research Council 1964, Seaman et al. 1964, Van Cleve 1966). Furthermore those who believe in rebound thromboembolism disagree as to whether the risks may be mitigated by gradual as opposed to abrupt withdrawal. Gradual withdrawal, first advocated by Cosgriff (1953), has been widely used since. The method was later supported on clinical grounds by Lieberman and Linder (1965) and on experimental grounds by Poller and Thomson (1965). However, Sharland (1966) and Michaels and Beamish (1967) have suggested that gradual reduction of anticoagulant dosage is without benefit. The doubts as to the value of long-term anticoagulant therapy in myocardial ischsemic disease and the risks attendant on its use prompted us to reassess patients at this hospital who were on such treatment. 115 patients were reviewed. In some treatment was continued, in others it was stopped, either abruptly, or gradually over a period of six weeks. Patients and Methods All but 2 of the patients were under the care of one of us, and were part of a population attending an anticoagulant clinic. They had received treatment for periods varying between nine months and ten years, most of them for over two years. Anticoagulant control had been regulated by Quick’s onestage technique, a prothrombin index of 40-50% being achieved in most of the patients for most of the time. All 115 *

appointment: assistant professor College, Mangalore, India.

Present

PROF.

JENNETT:

of

medicine, Kasturba Medical

REFERENCES

Ascroft, P. B. (1941) Br. med. J. i, 739. Caveness, W. F. (1963) J. Neurosurg. 20, 570. Evans, J. H. (1963) Neurology, Minneap. 13, 207. Hendrick, E. B., Harris, L. (1968) J. Trauma, 8, 547. Jennett, W. B. (1962) Epilepsy after Blunt Head Injuries. London. (1965) Br. med. J. i, 1215. — Lewin, W. S. (1960) J. Neurol. Neurosurg. Psychiat. 23, 295. Phillips, G. (1954) ibid. 17, 1. Russell, W. R., Whitty, C. W. M. (1952) ibid. 15, 93. Walker, A. E. (1957) J. Am. med. Ass. 184, 1636. Whitty, C. W. M. (1947) Brain, 70, 416. —

a

double-blind prospective trial with follow-up of nine months no significant

In