- Email: [email protected]
A new clinical scale of carpal tunnel syndrome: validation of the measurement and clinical-neurophysiological assessment
Clinical Neurophysiology 113 (2002) 71–77 www.elsevier.com/locate/clinph
A new clinical scale of carpal tunnel syndrome: validation of the measurement and clinical-neurophysiological assessment F. Giannini a,*, R. Cioni a, M. Mondelli b, R. Padua c, B. Gregori d, P. D’Amico e, L. Padua f,g a
Dipartimento di Neuroscienze, Sezione di Neurologia, Universita` di Siena, Policlinico ‘Le Scotte’, 53100 Siena, Italy b Servizio EMG, ASL 7, Siena, Italy c Dipartimento Ortopedia, Osp. S. Giacomo, Rome, Italy d A.Fa.R Osp. Fatebenefratelli, Isola Tiberina, Rome, Italy e Istituto di Medicina Fisica e Riabilitazione, Universita` ‘Tor Vergata’, Rome, Italy f Istituto di Neurologia, Universita` Cattolica S.C., Rome, Italy g Istituto Don Carlo Gnocchi, Rome, Italy Accepted 30 October 2001
Abstract Objective: To validate a new clinical scale of carpal tunnel syndrome (CTS). The scale is based on clinical history and physical examination findings and includes two figures. The first is a score determined by clinical history and objective findings. The second evaluates the presence/absence of pain as a dichotomous categorical score. Methods: One hundred and sixty-eight consecutive idiopathic CTS hands were studied in two centers (Rome, Siena). We compare the results of the historical-objective scale (Hi-Ob scale) with the results of other validated measurements of CTS severity: (1) the Italian version of the Boston Carpal Tunnel Questionnaire, (2) the neurophysiological classification adopted by the Italian CTS study group. Furthermore, for the Hi-Ob scale the intra-observer and inter-observer evaluations were assessed. Results: The main Hi-Ob parameter was positively related to the conventional validated measurements. Conversely, the category ‘PAIN’ of the Hi-Ob scale appeared unrelated to the other clinical and electrophysiological parameters. Intra- and inter-observer evaluation showed the reproducibility of the Hi-Ob assessment. Conclusions: Our data show that the Hi-Ob scale is a reliable measurement which may be useful in CTS evaluation either for clinical or for scientific purposes. q 2002 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Carpal tunnel syndrome; Clinical scale; Neurophysiological assessment; Patient-oriented assessment
1. Introduction The quantification of impairment severity is a fundamental phase of the approach of any disease and it can be considered a step of the diagnostic procedure. The neurophysiological aspect of the carpal tunnel syndrome (CTS) has been widely studied (AAEM, 1993a) and some neurophysiological classifications have been developed (Padua et al., 1997; Stevens, 1997). On the other hand the clinical diagnosis of CTS is usually easy and sensitive, and it is recommended as the gold standard in medical practice and electrophysiological studies (AAEM, 1993b). In the majority of cases the diagnosis is made on the basis of history and subjective symptoms. In fact, only in severe cases sensory and/or motor deficits can * Corresponding author. Tel.: 139-577-585300; fax: 139-577-270260. E-mail address: [email protected] (F. Giannini).
be detected through physical examination. Thus, some papers have focused on the clinical aspects mostly to rate the sensitivity and specificity of each historical and physical item (Katz et al., 1990; Stevens et al., 1999; D’Arcy and McGee, 2000), to graduate the diagnostic accuracy of the anatomic location and quality of symptoms reported by patients (Katz and Stirrat, 1990) or to evaluate the responsiveness to treatment (Katz et al., 1994; Bessette et al., 1997; Chang et al., 1998). Nevertheless, a simple and reliable tool assessing together symptoms and signs in order to classify the clinical severity of CTS is still lacking in the literature. We designed a clinical historical-objective (Hi-Ob) scale of CTS. The scale is a modified version of a previously reported scale (Giannini et al., 1991). The scale, which has no proper diagnostic purpose, has been used in a broad Italian multicentric study (Padua et al., 1998a,
1388-2457/02/$ - see front matter q 2002 Elsevier Science Ireland Ltd. All rights reserved. PII: S 1388-245 7(01)00704-0
CLINPH 2000753
72
F. Giannini et al. / Clinical Neurophysiology 113 (2002) 71–77
1999a,b,c,d) and appeared simple to use and useful to assess clinical severity of CTS patients. In order to validate this scale we studied 168 consecutive idiopathic CTS hands in two neurophysiological centers (Siena and Roma, 50 and 118 hands, respectively) through a multiperspective assessment by using validated neurophysiological and patient-oriented measurements of CTS. The results obtained with the Hi-Ob scale were compared to the data obtained with other measurements of CTS severity. Besides the correlation with other validated measurements of CTS, we also performed intra-observer and interobserver tests to evaluate the reproducibility of this scale. 2. Material and methods We adopted the multiperspective and multimeasurement protocol developed by the Italian CTS study group. An extensive and complete description of the study’s design was reported previously (Padua et al., 1998a, 1999d). Research received institutional approval and informed consent was obtained from each patient studied. The protocol is summarized below: 2.1. Definition of cases and data collection at the initial evaluation Diagnosis of CTS was based on the American Academy of Neurology clinical diagnostic criteria (AAN, 1993) summarized here: paresthesia, pain, swelling, weakness or clumsiness of the hand provoked or worsened by sleep, sustained hand or arm position, repetitive action of the hand or wrist that is mitigated by changing posture or by shaking of the hand; sensory deficits in the median innervated region of the hand and motor deficit or hypotrophy of the median innervated thenar muscle; symptoms elicited by Phalen test (1 min passive forced flexion of the wrist), performed on each patient. A detailed clinical history, a careful clinical examination and extended neurophysiologic evaluation (described below) were always performed to exclude the presence of other diseases that could be related to CTS (e.g. diabetes, polyneuropathy, endocrine diseases, etc.). Only idiopathic CTS (with no etiologic factors) were included. Each center had to provide idiopathic CTS hands subsequently referred to the laboratory. 2.2. Patient-oriented data: Boston Carpal Tunnel Questionnaire (BCTQ) A patient-oriented validated measurement was used: the Italian version of the BCTQ (Levine et al., 1993; Padua et al., 1998b). The BCTQ evaluates two domains of CTS, namely ‘symptoms’ (SYMPT), assessed with an 11-item scale and ‘functional status’ (FUNCT) assessed with an eight-item scale (each item has five possible responses). Each score (SYMPT and FUNCT) is calculated as the
mean of the responses of the individual items. Note that, in order to avoid influences of the physician and of neurophysiological data on the patient-oriented results, the BCTQ was always completed in the waiting room (before contact with the physician). 2.3. Physical examination and historical data: historicalobjective scale (Hi-Ob scale) Among data obtained with clinical history and physical examination (in each case performed after the BCTQ questionnaire and before the neurophysiological study) we have selected the following findings to create the Hi-Ob scale: (A) any kind of paresthesia in the hand (numbness, tingling, burning, etc.) with regard to its temporal onset and duration, (B) sensory function in the median nerve distribution of the hand, (C) motor function of median innervated muscles of the hand, (D) trophism of the thenar eminence and (E) pain, reported as dull or aching discomfort, in the hand, forearm or upper arm. Thus, the Hi-Ob scale includes two figures. The first is a score (Hi-Ob) of increasing severity, determined by symptoms and objective findings A–D, namely: Stage 0: no symptoms suggestive of CTS Stage 1: only nocturnal paresthesia Stage 2: diurnal paresthesia Stage 3: sensory deficit Stage 4: hypotrophy and/or motor deficit of median innervated thenar muscles Stage 5: complete atrophy or plegia of median innervated thenar muscles The Hi-Ob scale evaluate the presence or absence of pain (item E) separately, as the second dichotomous categorical score obtained by the patient with a forced-choice answer (yes or no). In other words, an associated mark is defined. Therefore, Hi-Ob score is composed by a number (stage) with or without the pain variable (PAIN); for example, a case with nocturnal and diurnal paresthesia which refers also to pain, is scored ‘2P,’ a case with sensory deficit (and no motor deficit) without pain symptom is scored ‘3.’ PAIN may be considered as a single patient-oriented item. For a correct application of the Hi-Ob scale we summarize some practical recommendations as follows: 0: After a critical analysis of reported symptoms, assign ‘0’ only if no paresthesia were present in the previous 2 weeks 1: Assign ‘1’ regardless of which and how many median innervated fingers have the symptom; assign the same score even in case of paresthesia on awakening if disappearance is rapid 2: See first line above; assign ‘2’ even in the case of transient diurnal symptoms after repetitive movements or prolonged postures 3: By use of wadding a comparative test should be
F. Giannini et al. / Clinical Neurophysiology 113 (2002) 71–77
performed on the palmar aspect of the second and third vs. fifth finger; assign the same score to hypoesthesia and to sensory lack of one or both median supplied fingers; the test may be also performed by use of other commonly used methods for sensory evaluation such as SemmesWeinstein monofilament or two-point discrimination 4: Selective hypotrophy of thenar muscles is assessed comparatively to other hand muscles; weakness is evaluated by resisted thumb abduction at right angle to the palm 5: Muscle atrophy is defined as concavity of the thenar eminence with respect to the palm plane and plegia is defined as inability of thumb abduction ventralward from the palm PAIN: as defined above, should be present in the last previous weeks A clinical scale is influenced by two features: (1) the ability or inability of the observer to repeat in multiple observation (intra-observer error), and (2) the bias of the observer (inter-observer error). The analysis of reliability in the intra-observer and inter-observer evaluation was performed according to Snedecor and Cochrane methods. Four independent observers, blinded to the electrodiagnostic results, assessed 50 consecutive patients to evaluate the inter-observer error. Moreover, each observer assessed the Hi-Ob scale twice with an interval of at least 2 days between the first and the second observation to evaluate the intraobserver error. Note that BCTQ scale and Hi-Ob scale have very different ways of quantifying the clinical picture but some common features may be found: both SYMPT and PAIN assess symptoms. Furthermore, Hi-Ob and FUNCT are in some way analogous. In fact, although Hi-Ob is a historicalobjective measurement, in the more severe scores (3, 4 and 5) it indirectly concerns the hand function. 2.4. Electrodiagnostic evaluation Electrodiagnostic studies were performed according to the protocol (Padua et al., 1998a, 1999d) inspired by American Association of Electrodiagnostic Medicine recommendations (AAEM, 1993b). When standard tests (median sensory nerve conduction velocity in two digit/wrist segments and median distal motor latency from the wrist to thenar eminence) yielded normal results, segmental over a short distance of 7–8 cm (Rossi et al., 1994; Padua et al., 1996) or comparative median/ulnar studies (Cioni et al., 1989; Uncini et al., 1989) were always performed. The severity of electrophysiological CTS impairment was assessed by a previously reported neurophysiological classification (Padua et al., 1997). CTS hands are divided into six groups on the basis of neurophysiological findings: negative, normal findings on all tests (NEG); minimal, abnormal segmental or comparative tests only (MIN); mild, abnormal digit/wrist sensory nerve conduction velocity and normal
73
distal motor latency (MILD); moderate, abnormal digit/ wrist sensory nerve conduction velocity and abnormal distal motor latency (MOD); severe, absence of sensory response and abnormal distal motor latency (SEV) and extreme, absence of motor and sensory responses (EXT). 2.5. Statistical analysis Statistical analysis was performed by using STAT-SOFT (OK-USA) package. Kolmogorov-Smirnov and Lilliefors probabilities tests were used to assess distribution. In the case of normal distribution and interval scale, correlation was assessed by using Pearson product-moment correlation coefficient whereas comparison of groups was performed by using Student’s t test. In the case of non-normal distribution, and in the case of measurement by ordinal scale (Hi-Ob) or nominal scale (neurophysiological classification), non-parametric analysis of correlation were assessed by using Spearman’s r test and comparison of groups was performed by using the MannWhitney U test. In order to evaluate the relationship between two dichotomous variables and to evaluate the difference between two groups in the frequency of one dichotomous variable, standard Pearson chi-square test ð2 £ 2 table) was performed. The Cohen kappa coefficient was calculated to assess the inter-observer and intra-observer variability. 3. Results One hundred and sixty-eight CTS hands were studied. One hundred and twelve patients were studied (56 patients were bilaterally examined): mean age 50.8 years (ranging from 21 to 91), female/male ratio ¼ 5:2, dominant/nondominant hand ratio ¼ 1:5. Positive Phalen sign was present in 70% of hands. Clinical data in the whole population and in the different neurophysiological classes are reported in Table 1. Two hands only, one with Hi-Ob score ¼ 2 and the other with Hi-Ob score ¼ 2P, had normal findings in all electrophysiological tests (NEG). The analysis of correlation showed that age is significantly related with Hi-Ob (P , 0:01, r ¼ 0:21) and with FUNCT (P , 0:05, r ¼ 0:17), while no significant correlation was found between age and SYMPT and PAIN. Hi-Ob was positively related to duration of symptoms with high statistical significance (P , 0:001, r ¼ 0:36). Even SYMPT and FUNCT were significantly related to duration of symptoms (P , 0:001, r ¼ 0:29 and P , 0:001, r ¼ 0:31, respectively). A highly significant positive relationship was observed between Hi-Ob score and neurophysiological classes (P , 0:001, r ¼ 0:42; Fig. 1). A positive significant correlation was also observed between neurophysiological classes and patient-oriented measurements: SYMPT (P , 0:05, r ¼ 0:17)., FUNCT (P , 0:001, r ¼ 0:28), PAIN (P , 0:02, r ¼ 0:18).
74
F. Giannini et al. / Clinical Neurophysiology 113 (2002) 71–77
Table 1 Mean value of clinical data in the different neurophysiological CTS classes a
Hands Age (years) Duration of symptoms (months) SYMPT FUNCT Hi-Ob PAIN a
NEG
MIN
MILD
MOD
SEV
EXT
TOT
2 [1.2] 29.5 (4.9) 9.0 (1.4) 2.4 (0.2) 1.3 (0.1) 2.0 (0.0) 50%
37 [22.0] 46.3 (11.8) 28.8 (31.8) 2.4 (0.9) 1.9 (0.7) 2.1 (0.7) 54%
47 [28.0] 48.2 (12.6) 32.5 (48.2) 2.6 (1.0) 1.8 (0.8) 2.2 (0.7) 53%
48 [28.6] 51.0 (16.1) 44.4 (54.7) 2.6 (0.9) 2.0 (0.9) 2.3 (0.8) 73%
29 [17.3] 58.2 (17.9) 80.5 (74.5) 3.1 (1.1) 2.6 (0.9) 3.2 (0.8) 83%
5 [3.0] 75.3 (10.6) 69.0 (59.1) 2.5 (0.9) 3.6 (1.0) 4.8 (0.5) 40%
168 [100] 50.8 (15.5) 44.0 (55.2) 2.6 (1.0) 2.1 (0.9) 2.4 (0.9) 64%
Abbreviations are as given in the text. Standard deviation in parentheses, percentage in square brackets.
A high linear correlation was observed between Hi-Ob score and FUNCT (P , 0:001, r ¼ 0:41; Fig. 2). Conversely, although a significant relationship was observed between Hi-Ob and SYMPT (P , 0:005, r ¼ 0:23) a particular behavior of the correlation was observed (Fig. 3): patients with Hi-Ob score ¼ 5 had a milder symptom picture than patients with minor clinical impairment (HiOb score ¼ 4 and 3). The second dichotomous categorical score of the scale (PAIN) was used to define two groups of hands (with and without referred pain: Table 2). Statistical analysis on these two groups of hands showed that, as already mentioned, pain is not significantly related to age and duration of symptoms. Conversely, patients with pain presented a significantly higher Hi-Ob, SYMPT and FUNCT scores (P , 0:001). Moreover, pain was related (P , 0:02) to a significantly higher neurophysiological impairment (Table 2). The occurrence of PAIN in each neurophysiological classes (Table 1) was higher in MOD and SEV groups, while pain was less frequent in more advanced cases (EXT). Likewise, the occurrence of PAIN was higher in Hi-Ob stages 2, 3 and 4 (Fig. 4), while stages 2 and 3 included the greatest number of CTS hands (72 and 58, respectively). Paired comparison among the evaluations of the obser-
vers produced a high rate of inter-observer reliability and the kappa intra-observer reproducibility indicated excellent correlation (k . 0:75).
4. Discussion Objective clinical examination does not reveal any abnormality in a great part of CTS hands. In this regard most of authors, who have assessed the diagnostic value of clinical data, focus their studies on symptoms reported by patients and signs obtained by physical examination, separately and in comparison with electrodiagnostic abnormalities. Thus, the sensitivity/specificity and the positive/negative predictive value of most common objective findings, such as sensory loss (two-point discrimination, Semmes-Weinstein monofilament or pinprick tests), thenar muscles weakness/atrophy and provocative tests (Tinel, Phalen and pressure provocation), have been widely stated (Katz et al., 1990; De Krom et al., 1990; D’Arcy and McGee, 2000; Mondelli et al., 2001). Regarding symptoms such as numbness, tingling, nocturnal paresthesias and pain, the most predictive diagnostic tool is thought to be the selfadministered ‘hand diagram’ that clearly defines four
Fig. 1. Relationship between neurophysiological picture and clinical scale.
F. Giannini et al. / Clinical Neurophysiology 113 (2002) 71–77
75
Fig. 2. Relationship between clinical scale and hand function.
patterns of decreasing diagnostic certainty (‘classic, probable, possible or unlikely’), but does not rate the clinical impairment severity (Katz and Stirrat, 1990; Stevens et al., 1999). For this fundamental purpose the instruments more carefully validated and commonly used are diseasespecific self-administered questionnaires, such as BCTQ and others subsequently modified (Levine et al., 1993; Chang et al., 1998; Stevens et al., 1999; You et al., 1999; Bland, 2000). Nevertheless using these severity scores, provided by patient-oriented items only, symptoms and functions are summarized by unique numbers that are not able to characterize the primary clinical feature of each single patient. This aim may be achieved only through a clinical classification or scale which takes into account both the patient and physician points of view. We designed a new clinical scale of CTS severity that includes some items concerning the historical picture, which are commonly considered the key information for clinical
diagnosis, and other parameters such as objective findings and a patient-oriented item such as ‘pain.’ Besides the fact that scale items has been suggested by an extensive clinical experience, by studies mentioned above and by AAN recommendations (AAN, 1993), the designed progression of score from subjective sensory symptoms to most severe motor impairment is in accordance with pathological grounds of the disease and reflect different stages in the development of the median nerve lesion inside the carpal tunnel (Sunderland, 1991). In this respect the earlier degree, due to increase of intrafascicular pressure, is characterized by hyperexcitability and spontaneous discharge of a portion of sensory fibers causing attacks of paresthesia and/or pain, often patchily distributed over median field, but with no clinical sensory loss. In the following stage the endoneural edema allows structural changes in nervous fibers inducing first the sensory deficit and later the weakness (but no paralysis) of thenar muscle or both findings at the same
Fig. 3. Relationship between clinical scale and symptoms.
76
F. Giannini et al. / Clinical Neurophysiology 113 (2002) 71–77
Table 2 Mean value of multimeasurement parameters in CTS patient with and without ‘referred pain’ (PAIN) a
Hands Age (years) Duration of symptoms (months) Hi-Ob SYMPT FUNCT Neurophysiological class a
PAIN 1 (‘pain’)
PAIN 2 (‘no pain’)
107 [64] 50.1 (16) 47.2 (56) 2.6 (0.8) 2.9 (0.9) 2.3 (0.9) 3.6 (1.1)
61 [36] 52.5 (13) 38.8 (54) 2.1 (1.1) 2.1 (0.8) 1.7 (0.8) 3.3 (1.1)
Difference between PAIN 1 and PAIN 2
Not significant Not significant P , 0:001 P , 0:001 P , 0:001 P , 0:02
Abbreviations are as given in the text. Standard deviation in parentheses, percentage in square brackets.
time. In the final degree of severity only few thinner fibers survive inside fibrosed fasciculi: touch sensory is lacking and thenar muscles become paralyzed and wasted. This scale was then validated in comparison to other accepted clinical and electrophysiological measurements. BCTQ scale and the Hi-Ob scale represent different ways of evaluating CTS patients, as they actually evaluate different aspects of the clinical picture. Mainly, the former is a self-administered patient questionnaire and the latter is basically a historical and physical evaluation performed by the neurophysiologist before electrophysiological examination. However, the two scales share some common features: both assess the symptom (by SYMPT and PAIN, respectively). Furthermore, Hi-Ob and FUNCT items are in some way analogous since Hi-Ob, being a symptom-sign measurement, indirectly concerns the hand function in the more severe scores (3, 4 and 5). As already mentioned, the Hi-Ob scale has been designed to evaluate the subjective figure ‘pain’ as a separate category. One reason for this is that only some patients complain of pain as a symptom related to CTS but, when reported, this symptom is often felt as ‘severe discomfort’ with great
influence in the severity of the clinical picture. In fact, pain is often the key symptom for surgical evaluation in clinical practice. Another reason is that, in single patient, pain often appeared to be quite unrelated to the other CTS clinical features. Our data showed that, at variance with other clinical data, pain was not related to age and duration of symptoms, while it was significantly related to SYMPT, FUNCT scores and neurophysiological classification. Moreover, pain was less frequently reported in more advanced cases, as compared to mild-moderate CTS. This study shows that our mixed scale covers all types and degrees of the disease. In fact this measurement allows us to reliably assess the majority of CTS hands which do not present objective motor-sensory impairment in terms of past history. Indeed, this scale also allows the assessment of the more severe CTS hands by objective measurement observed on physical examination. Our data confirm the previously compiled data showing that the Hi-Ob scale is a very reliable measurement of clinical events of CTS with a high congruence with other validated measurements (patient-oriented BCTQ and neurophysiological classification). Moreover, the results of the inter-observer and intra-observer testing also showed that the scale allowed highly reproducible results (low intra-observer and inter-observer error). This observation can be related to the clear terminology and simple methods used in stage definition. Therefore, score assignment of each case is performed easily and concisely which is very important for the daily clinical routine. In conclusion, our study shows that, in addition to other validated measurements, the Hi-Ob scale may be a useful tool in the evaluation of clinical impairment in CTS either for routine examination and for scientific purposes.
References
Fig. 4. Occurrence of PAIN and distribution of hands in clinical stages.
AAEM Quality Assurance Committee. Literature review of the usefulness of nerve conduction studies and electromyography for the evaluation of patients with carpal tunnel syndrome. Muscle Nerve 1993a;16:1392– 1414. AAEM, AAN, AAPMR. Practice parameter for electrodiagnostic studies in carpal tunnel syndrome: summary statement. Muscle Nerve 1993b;16:1390–1391.
F. Giannini et al. / Clinical Neurophysiology 113 (2002) 71–77 AAN, AAEM, AAPMR. Practice parameter for carpal tunnel syndrome (summary statement). Neurology 1993;43:2406–2409. Bessette L, Keller RB, Lew RA, Simmons BP, Fossel AH, Mooney N, Katz JN. Prognostic value of a hand symptom diagram in surgery for carpal tunnel syndrome. J Rheumatol 1997;24:726–734. Bland JDP. The value of the history in the diagnosis of carpal tunnel syndrome. J Hand Surg (Br) 2000;25B:445–450. Chang MH, Chiang HT, Lee SJ, Ger LP, Lo YK. Oral drug of choice in carpal tunnel syndrome. Neurology 1998;51:390–393. Cioni R, Passero S, Paradiso C, Giannini F, Battistini N, Rushworth G. Diagnostic specificity of sensory and motor nerve conduction variables in early detection of carpal tunnel syndrome. J Neurol 1989;236:208– 213. D’Arcy CA, McGee SM. Does this patient have carpal tunnel syndrome? J Am Med Assoc 2000;283:3110–3117. De Krom MC, Knipschild PG, Kester AD, Spaans F. Efficacy of provocative tests for diagnosis of carpal tunnel syndrome. Lancet 1990;335:393–395. Giannini F, Passero S, Cioni R, Paradiso C, Battistini N, Giordano N, Vaccai D, Marcolongo R. Electrophysiologic evaluation of local steroid injection in carpal tunnel syndrome. Arch Phys Med Rehabil 1991;72:738–742. Katz JN, Stirrat CR. A self-administered hand diagram for the diagnosis of carpal tunnel syndrome. J Hand Surg (Am) 1990;15A:360–363. Katz JN, Larson MG, Sabra A, Krarup C, Stirrat CR, Sethi R, Eaton HM, Fossel AH, Liang MH. The carpal tunnel syndrome: diagnostic utility of the history and physical examination findings. Ann Intern Med 1990;112:321–327. Katz JN, Gelbermann RH, Wright EA, Lew RA, Liang MH. Responsiveness of self-reported and objective measures of disease severity in carpal tunnel syndrome. Med Care 1994;32:1127–1133. Levine DW, Simmons BP, Koris MJ, Daltroy LH, Hohl GG, Fossel AH, Katz JN. A self-administered Questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome. J Bone Joint Surg Am 1993;75A:1585–1592. Mondelli M, Passero S, Giannini F. Provocative tests in different stages of carpal tunnel syndrome. Clin Neurol Neurosurg 2001;103:178–183. Padua L, Lo Monaco M, Valente EM, Tonali P. A useful electrophysiologic parameter for diagnosis of carpal tunnel syndrome. Muscle Nerve 1996;19:48–53. Padua L, Lo Monaco M, Gregori B, Valente EM, Padua R, Tonali P. Neurophysiological classification and sensitivity in 500 carpal tunnel syndrome hands. Acta Neurol Scand 1997;96:211–217.
77
Padua L, Padua R, Lo Monaco M, Romanini E, Tonali P, for the Italian CTS Study Group. Italian Multicentric study of carpal tunnel syndrome: study design. Ital J Neurol Sci 1998a;19:285–289. Padua R, Padua L, Romanini E, Aulisa L, Lupparelli S, Sanguinetti C. Versione italiana del questionario Boston Carpal Tunnel: valutazione preliminare. Giornale Ital Ortoped Traumatol 1998b;24:123–129. Padua L, Aprile I, Lo Monaco M, Padua R, Pasqualetti P, Nazzaro M, Tonali P, for the Italian CTS Study Group. Italian multicentre study of Carpal tunnel syndrome: clinical-neurophysiological picture and diagnostic pathway in 461 patients and differences between the populations enrolled in the Northern, Central and Southern centres. Ital J Neurol Sci 1999a;20:309–313. Padua L, Giannini F, Girlanda P, Insola A, Luchetti R, Lo Monaco M, Padua R, Uncini A, Tonali P, for the Italian CTS Study Group. Usefulness of segmental and comparative tests in the electrodiagnosis of carpal tunnel syndrome: the Italian multicenter study. Ital J Neurol Sci 1999b;20:315–320. Padua L, Padua R, Aprile I, Tonali P, for the Italian CTS Study Group. Italian multicentre study of Carpal tunnel syndrome (1123 hands) – differences of clinical-neurophysiological picture between male and female patients. J Hand Surg (Br) 1999c;24B(5):579–582. Padua L, Padua R, Lo Monaco M, Aprile I, Tonali P. Multiperspective assessment of carpal tunnel syndrome: a multicenter study. Neurology 1999d;53:1654–1659. Rossi S, Giannini F, Passero S, Paradiso C, Battistini N, Cioni R. Sensory neural conduction of median nerve from digits and palm stimulation in carpal tunnel syndrome. Electroenceph clin Neurophysiol 1994;93: 330–334. Stevens JC. AAEM minimonograph #26: the electrodiagnosis of carpal tunnel syndrome. Muscle Nerve 1997;20(12):1477–1486. Stevens JC, Smith BE, Weaver AL, Bosch EP, Deen HG, Wilkens JA. Symptoms of 100 patients with electromyographically verified carpal tunnel syndrome. Muscle Nerve 1999;22:1448–1456. Sunderland S. Causes of injury, terminology, compression nerve injury. In: Sunderland S, editor. Nerve injuries and their repair. A critical appraisal, London: Churchill Livingstone, 1991. pp. 129–146. Uncini A, Lange DJ, Solomon M, Soliven B, Meer J, Lovelace RE. Ring finger testing in carpal tunnel syndrome: a comparative study of diagnostic utility. Muscle Nerve 1989;12:735–741. You H, Simmons Z, Freivalds A, Kothari MJ, Naidu SH. Relationships between clinical symptom severity scales and nerve conduction measures in carpal tunnel syndrome. Muscle Nerve 1999;22:497–501.
A new clinical scale of carpal tunnel syndrome: validation of the measurement and clinical-neurophysiological assessment F. Giannini a,*, R. Cioni a, M. Mondelli b, R. Padua c, B. Gregori d, P. D’Amico e, L. Padua f,g a
Dipartimento di Neuroscienze, Sezione di Neurologia, Universita` di Siena, Policlinico ‘Le Scotte’, 53100 Siena, Italy b Servizio EMG, ASL 7, Siena, Italy c Dipartimento Ortopedia, Osp. S. Giacomo, Rome, Italy d A.Fa.R Osp. Fatebenefratelli, Isola Tiberina, Rome, Italy e Istituto di Medicina Fisica e Riabilitazione, Universita` ‘Tor Vergata’, Rome, Italy f Istituto di Neurologia, Universita` Cattolica S.C., Rome, Italy g Istituto Don Carlo Gnocchi, Rome, Italy Accepted 30 October 2001
Abstract Objective: To validate a new clinical scale of carpal tunnel syndrome (CTS). The scale is based on clinical history and physical examination findings and includes two figures. The first is a score determined by clinical history and objective findings. The second evaluates the presence/absence of pain as a dichotomous categorical score. Methods: One hundred and sixty-eight consecutive idiopathic CTS hands were studied in two centers (Rome, Siena). We compare the results of the historical-objective scale (Hi-Ob scale) with the results of other validated measurements of CTS severity: (1) the Italian version of the Boston Carpal Tunnel Questionnaire, (2) the neurophysiological classification adopted by the Italian CTS study group. Furthermore, for the Hi-Ob scale the intra-observer and inter-observer evaluations were assessed. Results: The main Hi-Ob parameter was positively related to the conventional validated measurements. Conversely, the category ‘PAIN’ of the Hi-Ob scale appeared unrelated to the other clinical and electrophysiological parameters. Intra- and inter-observer evaluation showed the reproducibility of the Hi-Ob assessment. Conclusions: Our data show that the Hi-Ob scale is a reliable measurement which may be useful in CTS evaluation either for clinical or for scientific purposes. q 2002 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Carpal tunnel syndrome; Clinical scale; Neurophysiological assessment; Patient-oriented assessment
1. Introduction The quantification of impairment severity is a fundamental phase of the approach of any disease and it can be considered a step of the diagnostic procedure. The neurophysiological aspect of the carpal tunnel syndrome (CTS) has been widely studied (AAEM, 1993a) and some neurophysiological classifications have been developed (Padua et al., 1997; Stevens, 1997). On the other hand the clinical diagnosis of CTS is usually easy and sensitive, and it is recommended as the gold standard in medical practice and electrophysiological studies (AAEM, 1993b). In the majority of cases the diagnosis is made on the basis of history and subjective symptoms. In fact, only in severe cases sensory and/or motor deficits can * Corresponding author. Tel.: 139-577-585300; fax: 139-577-270260. E-mail address: [email protected] (F. Giannini).
be detected through physical examination. Thus, some papers have focused on the clinical aspects mostly to rate the sensitivity and specificity of each historical and physical item (Katz et al., 1990; Stevens et al., 1999; D’Arcy and McGee, 2000), to graduate the diagnostic accuracy of the anatomic location and quality of symptoms reported by patients (Katz and Stirrat, 1990) or to evaluate the responsiveness to treatment (Katz et al., 1994; Bessette et al., 1997; Chang et al., 1998). Nevertheless, a simple and reliable tool assessing together symptoms and signs in order to classify the clinical severity of CTS is still lacking in the literature. We designed a clinical historical-objective (Hi-Ob) scale of CTS. The scale is a modified version of a previously reported scale (Giannini et al., 1991). The scale, which has no proper diagnostic purpose, has been used in a broad Italian multicentric study (Padua et al., 1998a,
1388-2457/02/$ - see front matter q 2002 Elsevier Science Ireland Ltd. All rights reserved. PII: S 1388-245 7(01)00704-0
CLINPH 2000753
72
F. Giannini et al. / Clinical Neurophysiology 113 (2002) 71–77
1999a,b,c,d) and appeared simple to use and useful to assess clinical severity of CTS patients. In order to validate this scale we studied 168 consecutive idiopathic CTS hands in two neurophysiological centers (Siena and Roma, 50 and 118 hands, respectively) through a multiperspective assessment by using validated neurophysiological and patient-oriented measurements of CTS. The results obtained with the Hi-Ob scale were compared to the data obtained with other measurements of CTS severity. Besides the correlation with other validated measurements of CTS, we also performed intra-observer and interobserver tests to evaluate the reproducibility of this scale. 2. Material and methods We adopted the multiperspective and multimeasurement protocol developed by the Italian CTS study group. An extensive and complete description of the study’s design was reported previously (Padua et al., 1998a, 1999d). Research received institutional approval and informed consent was obtained from each patient studied. The protocol is summarized below: 2.1. Definition of cases and data collection at the initial evaluation Diagnosis of CTS was based on the American Academy of Neurology clinical diagnostic criteria (AAN, 1993) summarized here: paresthesia, pain, swelling, weakness or clumsiness of the hand provoked or worsened by sleep, sustained hand or arm position, repetitive action of the hand or wrist that is mitigated by changing posture or by shaking of the hand; sensory deficits in the median innervated region of the hand and motor deficit or hypotrophy of the median innervated thenar muscle; symptoms elicited by Phalen test (1 min passive forced flexion of the wrist), performed on each patient. A detailed clinical history, a careful clinical examination and extended neurophysiologic evaluation (described below) were always performed to exclude the presence of other diseases that could be related to CTS (e.g. diabetes, polyneuropathy, endocrine diseases, etc.). Only idiopathic CTS (with no etiologic factors) were included. Each center had to provide idiopathic CTS hands subsequently referred to the laboratory. 2.2. Patient-oriented data: Boston Carpal Tunnel Questionnaire (BCTQ) A patient-oriented validated measurement was used: the Italian version of the BCTQ (Levine et al., 1993; Padua et al., 1998b). The BCTQ evaluates two domains of CTS, namely ‘symptoms’ (SYMPT), assessed with an 11-item scale and ‘functional status’ (FUNCT) assessed with an eight-item scale (each item has five possible responses). Each score (SYMPT and FUNCT) is calculated as the
mean of the responses of the individual items. Note that, in order to avoid influences of the physician and of neurophysiological data on the patient-oriented results, the BCTQ was always completed in the waiting room (before contact with the physician). 2.3. Physical examination and historical data: historicalobjective scale (Hi-Ob scale) Among data obtained with clinical history and physical examination (in each case performed after the BCTQ questionnaire and before the neurophysiological study) we have selected the following findings to create the Hi-Ob scale: (A) any kind of paresthesia in the hand (numbness, tingling, burning, etc.) with regard to its temporal onset and duration, (B) sensory function in the median nerve distribution of the hand, (C) motor function of median innervated muscles of the hand, (D) trophism of the thenar eminence and (E) pain, reported as dull or aching discomfort, in the hand, forearm or upper arm. Thus, the Hi-Ob scale includes two figures. The first is a score (Hi-Ob) of increasing severity, determined by symptoms and objective findings A–D, namely: Stage 0: no symptoms suggestive of CTS Stage 1: only nocturnal paresthesia Stage 2: diurnal paresthesia Stage 3: sensory deficit Stage 4: hypotrophy and/or motor deficit of median innervated thenar muscles Stage 5: complete atrophy or plegia of median innervated thenar muscles The Hi-Ob scale evaluate the presence or absence of pain (item E) separately, as the second dichotomous categorical score obtained by the patient with a forced-choice answer (yes or no). In other words, an associated mark is defined. Therefore, Hi-Ob score is composed by a number (stage) with or without the pain variable (PAIN); for example, a case with nocturnal and diurnal paresthesia which refers also to pain, is scored ‘2P,’ a case with sensory deficit (and no motor deficit) without pain symptom is scored ‘3.’ PAIN may be considered as a single patient-oriented item. For a correct application of the Hi-Ob scale we summarize some practical recommendations as follows: 0: After a critical analysis of reported symptoms, assign ‘0’ only if no paresthesia were present in the previous 2 weeks 1: Assign ‘1’ regardless of which and how many median innervated fingers have the symptom; assign the same score even in case of paresthesia on awakening if disappearance is rapid 2: See first line above; assign ‘2’ even in the case of transient diurnal symptoms after repetitive movements or prolonged postures 3: By use of wadding a comparative test should be
F. Giannini et al. / Clinical Neurophysiology 113 (2002) 71–77
performed on the palmar aspect of the second and third vs. fifth finger; assign the same score to hypoesthesia and to sensory lack of one or both median supplied fingers; the test may be also performed by use of other commonly used methods for sensory evaluation such as SemmesWeinstein monofilament or two-point discrimination 4: Selective hypotrophy of thenar muscles is assessed comparatively to other hand muscles; weakness is evaluated by resisted thumb abduction at right angle to the palm 5: Muscle atrophy is defined as concavity of the thenar eminence with respect to the palm plane and plegia is defined as inability of thumb abduction ventralward from the palm PAIN: as defined above, should be present in the last previous weeks A clinical scale is influenced by two features: (1) the ability or inability of the observer to repeat in multiple observation (intra-observer error), and (2) the bias of the observer (inter-observer error). The analysis of reliability in the intra-observer and inter-observer evaluation was performed according to Snedecor and Cochrane methods. Four independent observers, blinded to the electrodiagnostic results, assessed 50 consecutive patients to evaluate the inter-observer error. Moreover, each observer assessed the Hi-Ob scale twice with an interval of at least 2 days between the first and the second observation to evaluate the intraobserver error. Note that BCTQ scale and Hi-Ob scale have very different ways of quantifying the clinical picture but some common features may be found: both SYMPT and PAIN assess symptoms. Furthermore, Hi-Ob and FUNCT are in some way analogous. In fact, although Hi-Ob is a historicalobjective measurement, in the more severe scores (3, 4 and 5) it indirectly concerns the hand function. 2.4. Electrodiagnostic evaluation Electrodiagnostic studies were performed according to the protocol (Padua et al., 1998a, 1999d) inspired by American Association of Electrodiagnostic Medicine recommendations (AAEM, 1993b). When standard tests (median sensory nerve conduction velocity in two digit/wrist segments and median distal motor latency from the wrist to thenar eminence) yielded normal results, segmental over a short distance of 7–8 cm (Rossi et al., 1994; Padua et al., 1996) or comparative median/ulnar studies (Cioni et al., 1989; Uncini et al., 1989) were always performed. The severity of electrophysiological CTS impairment was assessed by a previously reported neurophysiological classification (Padua et al., 1997). CTS hands are divided into six groups on the basis of neurophysiological findings: negative, normal findings on all tests (NEG); minimal, abnormal segmental or comparative tests only (MIN); mild, abnormal digit/wrist sensory nerve conduction velocity and normal
73
distal motor latency (MILD); moderate, abnormal digit/ wrist sensory nerve conduction velocity and abnormal distal motor latency (MOD); severe, absence of sensory response and abnormal distal motor latency (SEV) and extreme, absence of motor and sensory responses (EXT). 2.5. Statistical analysis Statistical analysis was performed by using STAT-SOFT (OK-USA) package. Kolmogorov-Smirnov and Lilliefors probabilities tests were used to assess distribution. In the case of normal distribution and interval scale, correlation was assessed by using Pearson product-moment correlation coefficient whereas comparison of groups was performed by using Student’s t test. In the case of non-normal distribution, and in the case of measurement by ordinal scale (Hi-Ob) or nominal scale (neurophysiological classification), non-parametric analysis of correlation were assessed by using Spearman’s r test and comparison of groups was performed by using the MannWhitney U test. In order to evaluate the relationship between two dichotomous variables and to evaluate the difference between two groups in the frequency of one dichotomous variable, standard Pearson chi-square test ð2 £ 2 table) was performed. The Cohen kappa coefficient was calculated to assess the inter-observer and intra-observer variability. 3. Results One hundred and sixty-eight CTS hands were studied. One hundred and twelve patients were studied (56 patients were bilaterally examined): mean age 50.8 years (ranging from 21 to 91), female/male ratio ¼ 5:2, dominant/nondominant hand ratio ¼ 1:5. Positive Phalen sign was present in 70% of hands. Clinical data in the whole population and in the different neurophysiological classes are reported in Table 1. Two hands only, one with Hi-Ob score ¼ 2 and the other with Hi-Ob score ¼ 2P, had normal findings in all electrophysiological tests (NEG). The analysis of correlation showed that age is significantly related with Hi-Ob (P , 0:01, r ¼ 0:21) and with FUNCT (P , 0:05, r ¼ 0:17), while no significant correlation was found between age and SYMPT and PAIN. Hi-Ob was positively related to duration of symptoms with high statistical significance (P , 0:001, r ¼ 0:36). Even SYMPT and FUNCT were significantly related to duration of symptoms (P , 0:001, r ¼ 0:29 and P , 0:001, r ¼ 0:31, respectively). A highly significant positive relationship was observed between Hi-Ob score and neurophysiological classes (P , 0:001, r ¼ 0:42; Fig. 1). A positive significant correlation was also observed between neurophysiological classes and patient-oriented measurements: SYMPT (P , 0:05, r ¼ 0:17)., FUNCT (P , 0:001, r ¼ 0:28), PAIN (P , 0:02, r ¼ 0:18).
74
F. Giannini et al. / Clinical Neurophysiology 113 (2002) 71–77
Table 1 Mean value of clinical data in the different neurophysiological CTS classes a
Hands Age (years) Duration of symptoms (months) SYMPT FUNCT Hi-Ob PAIN a
NEG
MIN
MILD
MOD
SEV
EXT
TOT
2 [1.2] 29.5 (4.9) 9.0 (1.4) 2.4 (0.2) 1.3 (0.1) 2.0 (0.0) 50%
37 [22.0] 46.3 (11.8) 28.8 (31.8) 2.4 (0.9) 1.9 (0.7) 2.1 (0.7) 54%
47 [28.0] 48.2 (12.6) 32.5 (48.2) 2.6 (1.0) 1.8 (0.8) 2.2 (0.7) 53%
48 [28.6] 51.0 (16.1) 44.4 (54.7) 2.6 (0.9) 2.0 (0.9) 2.3 (0.8) 73%
29 [17.3] 58.2 (17.9) 80.5 (74.5) 3.1 (1.1) 2.6 (0.9) 3.2 (0.8) 83%
5 [3.0] 75.3 (10.6) 69.0 (59.1) 2.5 (0.9) 3.6 (1.0) 4.8 (0.5) 40%
168 [100] 50.8 (15.5) 44.0 (55.2) 2.6 (1.0) 2.1 (0.9) 2.4 (0.9) 64%
Abbreviations are as given in the text. Standard deviation in parentheses, percentage in square brackets.
A high linear correlation was observed between Hi-Ob score and FUNCT (P , 0:001, r ¼ 0:41; Fig. 2). Conversely, although a significant relationship was observed between Hi-Ob and SYMPT (P , 0:005, r ¼ 0:23) a particular behavior of the correlation was observed (Fig. 3): patients with Hi-Ob score ¼ 5 had a milder symptom picture than patients with minor clinical impairment (HiOb score ¼ 4 and 3). The second dichotomous categorical score of the scale (PAIN) was used to define two groups of hands (with and without referred pain: Table 2). Statistical analysis on these two groups of hands showed that, as already mentioned, pain is not significantly related to age and duration of symptoms. Conversely, patients with pain presented a significantly higher Hi-Ob, SYMPT and FUNCT scores (P , 0:001). Moreover, pain was related (P , 0:02) to a significantly higher neurophysiological impairment (Table 2). The occurrence of PAIN in each neurophysiological classes (Table 1) was higher in MOD and SEV groups, while pain was less frequent in more advanced cases (EXT). Likewise, the occurrence of PAIN was higher in Hi-Ob stages 2, 3 and 4 (Fig. 4), while stages 2 and 3 included the greatest number of CTS hands (72 and 58, respectively). Paired comparison among the evaluations of the obser-
vers produced a high rate of inter-observer reliability and the kappa intra-observer reproducibility indicated excellent correlation (k . 0:75).
4. Discussion Objective clinical examination does not reveal any abnormality in a great part of CTS hands. In this regard most of authors, who have assessed the diagnostic value of clinical data, focus their studies on symptoms reported by patients and signs obtained by physical examination, separately and in comparison with electrodiagnostic abnormalities. Thus, the sensitivity/specificity and the positive/negative predictive value of most common objective findings, such as sensory loss (two-point discrimination, Semmes-Weinstein monofilament or pinprick tests), thenar muscles weakness/atrophy and provocative tests (Tinel, Phalen and pressure provocation), have been widely stated (Katz et al., 1990; De Krom et al., 1990; D’Arcy and McGee, 2000; Mondelli et al., 2001). Regarding symptoms such as numbness, tingling, nocturnal paresthesias and pain, the most predictive diagnostic tool is thought to be the selfadministered ‘hand diagram’ that clearly defines four
Fig. 1. Relationship between neurophysiological picture and clinical scale.
F. Giannini et al. / Clinical Neurophysiology 113 (2002) 71–77
75
Fig. 2. Relationship between clinical scale and hand function.
patterns of decreasing diagnostic certainty (‘classic, probable, possible or unlikely’), but does not rate the clinical impairment severity (Katz and Stirrat, 1990; Stevens et al., 1999). For this fundamental purpose the instruments more carefully validated and commonly used are diseasespecific self-administered questionnaires, such as BCTQ and others subsequently modified (Levine et al., 1993; Chang et al., 1998; Stevens et al., 1999; You et al., 1999; Bland, 2000). Nevertheless using these severity scores, provided by patient-oriented items only, symptoms and functions are summarized by unique numbers that are not able to characterize the primary clinical feature of each single patient. This aim may be achieved only through a clinical classification or scale which takes into account both the patient and physician points of view. We designed a new clinical scale of CTS severity that includes some items concerning the historical picture, which are commonly considered the key information for clinical
diagnosis, and other parameters such as objective findings and a patient-oriented item such as ‘pain.’ Besides the fact that scale items has been suggested by an extensive clinical experience, by studies mentioned above and by AAN recommendations (AAN, 1993), the designed progression of score from subjective sensory symptoms to most severe motor impairment is in accordance with pathological grounds of the disease and reflect different stages in the development of the median nerve lesion inside the carpal tunnel (Sunderland, 1991). In this respect the earlier degree, due to increase of intrafascicular pressure, is characterized by hyperexcitability and spontaneous discharge of a portion of sensory fibers causing attacks of paresthesia and/or pain, often patchily distributed over median field, but with no clinical sensory loss. In the following stage the endoneural edema allows structural changes in nervous fibers inducing first the sensory deficit and later the weakness (but no paralysis) of thenar muscle or both findings at the same
Fig. 3. Relationship between clinical scale and symptoms.
76
F. Giannini et al. / Clinical Neurophysiology 113 (2002) 71–77
Table 2 Mean value of multimeasurement parameters in CTS patient with and without ‘referred pain’ (PAIN) a
Hands Age (years) Duration of symptoms (months) Hi-Ob SYMPT FUNCT Neurophysiological class a
PAIN 1 (‘pain’)
PAIN 2 (‘no pain’)
107 [64] 50.1 (16) 47.2 (56) 2.6 (0.8) 2.9 (0.9) 2.3 (0.9) 3.6 (1.1)
61 [36] 52.5 (13) 38.8 (54) 2.1 (1.1) 2.1 (0.8) 1.7 (0.8) 3.3 (1.1)
Difference between PAIN 1 and PAIN 2
Not significant Not significant P , 0:001 P , 0:001 P , 0:001 P , 0:02
Abbreviations are as given in the text. Standard deviation in parentheses, percentage in square brackets.
time. In the final degree of severity only few thinner fibers survive inside fibrosed fasciculi: touch sensory is lacking and thenar muscles become paralyzed and wasted. This scale was then validated in comparison to other accepted clinical and electrophysiological measurements. BCTQ scale and the Hi-Ob scale represent different ways of evaluating CTS patients, as they actually evaluate different aspects of the clinical picture. Mainly, the former is a self-administered patient questionnaire and the latter is basically a historical and physical evaluation performed by the neurophysiologist before electrophysiological examination. However, the two scales share some common features: both assess the symptom (by SYMPT and PAIN, respectively). Furthermore, Hi-Ob and FUNCT items are in some way analogous since Hi-Ob, being a symptom-sign measurement, indirectly concerns the hand function in the more severe scores (3, 4 and 5). As already mentioned, the Hi-Ob scale has been designed to evaluate the subjective figure ‘pain’ as a separate category. One reason for this is that only some patients complain of pain as a symptom related to CTS but, when reported, this symptom is often felt as ‘severe discomfort’ with great
influence in the severity of the clinical picture. In fact, pain is often the key symptom for surgical evaluation in clinical practice. Another reason is that, in single patient, pain often appeared to be quite unrelated to the other CTS clinical features. Our data showed that, at variance with other clinical data, pain was not related to age and duration of symptoms, while it was significantly related to SYMPT, FUNCT scores and neurophysiological classification. Moreover, pain was less frequently reported in more advanced cases, as compared to mild-moderate CTS. This study shows that our mixed scale covers all types and degrees of the disease. In fact this measurement allows us to reliably assess the majority of CTS hands which do not present objective motor-sensory impairment in terms of past history. Indeed, this scale also allows the assessment of the more severe CTS hands by objective measurement observed on physical examination. Our data confirm the previously compiled data showing that the Hi-Ob scale is a very reliable measurement of clinical events of CTS with a high congruence with other validated measurements (patient-oriented BCTQ and neurophysiological classification). Moreover, the results of the inter-observer and intra-observer testing also showed that the scale allowed highly reproducible results (low intra-observer and inter-observer error). This observation can be related to the clear terminology and simple methods used in stage definition. Therefore, score assignment of each case is performed easily and concisely which is very important for the daily clinical routine. In conclusion, our study shows that, in addition to other validated measurements, the Hi-Ob scale may be a useful tool in the evaluation of clinical impairment in CTS either for routine examination and for scientific purposes.
References
Fig. 4. Occurrence of PAIN and distribution of hands in clinical stages.
AAEM Quality Assurance Committee. Literature review of the usefulness of nerve conduction studies and electromyography for the evaluation of patients with carpal tunnel syndrome. Muscle Nerve 1993a;16:1392– 1414. AAEM, AAN, AAPMR. Practice parameter for electrodiagnostic studies in carpal tunnel syndrome: summary statement. Muscle Nerve 1993b;16:1390–1391.
F. Giannini et al. / Clinical Neurophysiology 113 (2002) 71–77 AAN, AAEM, AAPMR. Practice parameter for carpal tunnel syndrome (summary statement). Neurology 1993;43:2406–2409. Bessette L, Keller RB, Lew RA, Simmons BP, Fossel AH, Mooney N, Katz JN. Prognostic value of a hand symptom diagram in surgery for carpal tunnel syndrome. J Rheumatol 1997;24:726–734. Bland JDP. The value of the history in the diagnosis of carpal tunnel syndrome. J Hand Surg (Br) 2000;25B:445–450. Chang MH, Chiang HT, Lee SJ, Ger LP, Lo YK. Oral drug of choice in carpal tunnel syndrome. Neurology 1998;51:390–393. Cioni R, Passero S, Paradiso C, Giannini F, Battistini N, Rushworth G. Diagnostic specificity of sensory and motor nerve conduction variables in early detection of carpal tunnel syndrome. J Neurol 1989;236:208– 213. D’Arcy CA, McGee SM. Does this patient have carpal tunnel syndrome? J Am Med Assoc 2000;283:3110–3117. De Krom MC, Knipschild PG, Kester AD, Spaans F. Efficacy of provocative tests for diagnosis of carpal tunnel syndrome. Lancet 1990;335:393–395. Giannini F, Passero S, Cioni R, Paradiso C, Battistini N, Giordano N, Vaccai D, Marcolongo R. Electrophysiologic evaluation of local steroid injection in carpal tunnel syndrome. Arch Phys Med Rehabil 1991;72:738–742. Katz JN, Stirrat CR. A self-administered hand diagram for the diagnosis of carpal tunnel syndrome. J Hand Surg (Am) 1990;15A:360–363. Katz JN, Larson MG, Sabra A, Krarup C, Stirrat CR, Sethi R, Eaton HM, Fossel AH, Liang MH. The carpal tunnel syndrome: diagnostic utility of the history and physical examination findings. Ann Intern Med 1990;112:321–327. Katz JN, Gelbermann RH, Wright EA, Lew RA, Liang MH. Responsiveness of self-reported and objective measures of disease severity in carpal tunnel syndrome. Med Care 1994;32:1127–1133. Levine DW, Simmons BP, Koris MJ, Daltroy LH, Hohl GG, Fossel AH, Katz JN. A self-administered Questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome. J Bone Joint Surg Am 1993;75A:1585–1592. Mondelli M, Passero S, Giannini F. Provocative tests in different stages of carpal tunnel syndrome. Clin Neurol Neurosurg 2001;103:178–183. Padua L, Lo Monaco M, Valente EM, Tonali P. A useful electrophysiologic parameter for diagnosis of carpal tunnel syndrome. Muscle Nerve 1996;19:48–53. Padua L, Lo Monaco M, Gregori B, Valente EM, Padua R, Tonali P. Neurophysiological classification and sensitivity in 500 carpal tunnel syndrome hands. Acta Neurol Scand 1997;96:211–217.
77
Padua L, Padua R, Lo Monaco M, Romanini E, Tonali P, for the Italian CTS Study Group. Italian Multicentric study of carpal tunnel syndrome: study design. Ital J Neurol Sci 1998a;19:285–289. Padua R, Padua L, Romanini E, Aulisa L, Lupparelli S, Sanguinetti C. Versione italiana del questionario Boston Carpal Tunnel: valutazione preliminare. Giornale Ital Ortoped Traumatol 1998b;24:123–129. Padua L, Aprile I, Lo Monaco M, Padua R, Pasqualetti P, Nazzaro M, Tonali P, for the Italian CTS Study Group. Italian multicentre study of Carpal tunnel syndrome: clinical-neurophysiological picture and diagnostic pathway in 461 patients and differences between the populations enrolled in the Northern, Central and Southern centres. Ital J Neurol Sci 1999a;20:309–313. Padua L, Giannini F, Girlanda P, Insola A, Luchetti R, Lo Monaco M, Padua R, Uncini A, Tonali P, for the Italian CTS Study Group. Usefulness of segmental and comparative tests in the electrodiagnosis of carpal tunnel syndrome: the Italian multicenter study. Ital J Neurol Sci 1999b;20:315–320. Padua L, Padua R, Aprile I, Tonali P, for the Italian CTS Study Group. Italian multicentre study of Carpal tunnel syndrome (1123 hands) – differences of clinical-neurophysiological picture between male and female patients. J Hand Surg (Br) 1999c;24B(5):579–582. Padua L, Padua R, Lo Monaco M, Aprile I, Tonali P. Multiperspective assessment of carpal tunnel syndrome: a multicenter study. Neurology 1999d;53:1654–1659. Rossi S, Giannini F, Passero S, Paradiso C, Battistini N, Cioni R. Sensory neural conduction of median nerve from digits and palm stimulation in carpal tunnel syndrome. Electroenceph clin Neurophysiol 1994;93: 330–334. Stevens JC. AAEM minimonograph #26: the electrodiagnosis of carpal tunnel syndrome. Muscle Nerve 1997;20(12):1477–1486. Stevens JC, Smith BE, Weaver AL, Bosch EP, Deen HG, Wilkens JA. Symptoms of 100 patients with electromyographically verified carpal tunnel syndrome. Muscle Nerve 1999;22:1448–1456. Sunderland S. Causes of injury, terminology, compression nerve injury. In: Sunderland S, editor. Nerve injuries and their repair. A critical appraisal, London: Churchill Livingstone, 1991. pp. 129–146. Uncini A, Lange DJ, Solomon M, Soliven B, Meer J, Lovelace RE. Ring finger testing in carpal tunnel syndrome: a comparative study of diagnostic utility. Muscle Nerve 1989;12:735–741. You H, Simmons Z, Freivalds A, Kothari MJ, Naidu SH. Relationships between clinical symptom severity scales and nerve conduction measures in carpal tunnel syndrome. Muscle Nerve 1999;22:497–501.