M.C.T.F.M. De Krom

Consensus criteria for the classification of carpal tunnel syndrome in epidemiologic studies

Criteria for the classification of carpal tunnel syndrome for use in epidemiologic studies were developed by means of a consensus process. Twelve medical researchers with experience in conducting epidemiologic studies of carpal tunnel syndrome participated in the process. The group reached agreement on several conceptual issues. First, there is no perfect gold standard for carpal tunnel syndrome. The combination of electrodiagnostic study findings and symptom characteristics will provide the most accurate information for classification of carpal tunnel syndrome. Second, use of only electrodiagnostic study findings is not recommended. Finally, in the absence of electrodiagnostic studies, specific combinations of symptom characteristics and physical examination findings may be useful in some settings but are likely to result in greater misclassification of disease status.

Carpal tunnel syndrome prevalence in the general population

To study the prevalence of carpal tunnel syndrome (CTS) in the general population and the value of brachialgia paraesthetica nocturna (BPN) in diagnosing CTS, an age and sex stratified random sample of 715 subjects was taken from the population register of Maastricht (The Netherlands) and surrounding villages, between September 1983 and July 1985. The response rate was 70%. Of these, 12 CTS cases had already been diagnosed. Of the remaining subjects, 64 (13 men, 51 women) woke up because of BPN. Among these subjects 1 man and 23 women were found to have CTS. The prevalence rate of undetected CTS was 5.8% [95% confidence interval (CI): 3.5-8.1%] in adult women; 3.4 percent (95% CI: 1.5-5.3%) had already been diagnosed as CTS. The overall prevalence rate for men was 0.6% (95% CI 0.02-3.4%). These figures have to be regarded as minimal estimates. The overall diagnostic value of BPN for CTS was 38%, while for women only this was 45% (95% CI: 31-60%).

Diagnostic value of history and physical examination in patients suspected of lumbosacral nerve root compression

Objective: To evaluate patient characteristics, symptoms, and examination findings in the clinical diagnosis of lumbosacral nerve root compression causing sciatica. Methods: The study involved 274 patients with pain radiating into the leg. All had a standardised clinical assessment and magnetic resonance (MR) imaging. The associations between patient characteristics, clinical findings, and lumbosacral nerve root compression on MR imaging were analysed. Results: Nerve root compression was associated with three patient characteristics, three symptoms, and four physical examination findings (paresis, absence of tendon reflexes, a positive straight leg raising test, and increased finger-floor distance). Multivariate analysis, analysing the independent diagnostic value of the tests, showed that nerve root compression was predicted by two patient characteristics, four symptoms, and two signs (increased finger-floor distance and paresis). The straight leg raise test was not predictive. The area under the curve of the receiver-operating characteristic was 0.80 for the history items. It increased to 0.83 when the physical examination items were added. Conclusions: Various clinical findings were found to be associated with nerve root compression on MR imaging. While this set of findings agrees well with those commonly used in daily practice, the tests tended to have lower sensitivity and specificity than previously reported. Stepwise multivariate analysis showed that most of the diagnostic information revealed by physical examination findings had already been revealed by the history items.

Diagnostic value of history and physical examination in patients suspected of sciatica due to disc herniation: a systematic review.

Abstract We conducted a systematic review of the literature from 1965–1994 to assess the value of history and physical examination in the diagnosis of sciatica due to disc herniation; we also included population characteristics and features of the study design affecting diagnostic value. Studies on the diagnostic value of history and physical examination in the diagnosis of sciatica due to disc herniation are subject to important biases, and information on numerous signs and symptoms is scarce or absent. Our search revealed 37 studies meeting the selection criteria; these were systematically and independently read by three readers to determine diagnostic test properties using a standard scoring list to determine the methodological quality of the diagnostic information. A meta-analysis was performed when study results allowed statistical pooling. Few studies investigated the value of the history. Pain distribution seemed to be the only useful history item. Of the physical examination signs the straight leg raising test was the only sign consistently reported to be sensitive for sciatica due to disc herniation. However, the sensitivity values varied greatly, the pooled sensitivity and specificity values being 0.85 and 0.52, respectively. The crossed straight leg raising test was the only sign shown to be specific; the pooled sensitivity and specificity values were 0.30 and 0.84, respectively. There was considerable disagreement on the specificity of the other neurological signs (paresis, sensory loss, reflex loss). Several types of bias and other methodological drawbacks were encountered in the studies limiting the validity of the study results. As a result of these drawbacks it is probable that test sensitivity was overestimated and test specificity underestimated.

A cross-sectional study of subjective complaints in patients with epilepsy who seem to be well-controlled with anti-epileptic drugs

OBJECTIVES Side-effects of anti-epileptic drugs (AEDs) may be overlooked in patients with epilepsy in everyday clinical practice. The aim of this study was to assess the prevalence and severity of subjective complaints in patients who were considered to be well-controlled and to assess whether these complaints are related to medication, personality traits, or other determinants. METHODS We included patients with epilepsy who were considered to be well-controlled in a cross-sectional study in seven hospitals in the Netherlands. Their medication had not been changed for six months and an apparent reason to change the medication was lacking at the time of enrolment. Subjective complaints were assessed with a 46-item questionnaire. Using multivariable linear regression modeling, we assessed whether patient characteristics, epilepsy characteristics, medication, quality of life (Qolie-10), and personality traits (SCL-90) explained the presence and severity of complaints. RESULTS Of 173 included patients, 67% reported moderate to severe subjective complaints on the questionnaire. Cognitive complaints were reported most frequently. Multivariate modeling showed that 61% of the variance in reported complaints could be explained by included determinants. The prevalence and severity of complaints was associated with AED polytherapy and higher scores on psycho neuroticism. CONCLUSIONS Patients who were considered to be well-controlled proved to report an unexpectedly high number of subjective complaints. Both medication and aspects of personality contributed to the level of complaints. Our study illustrates that subjective side-effects are easily overlooked in everyday clinical practice, possibly because in practice a generally phrased question is used to detect side-effects.

Long-term effects of levetiracetam and topiramate in clinical practice: A head-to-head comparison.

OBJECTIVE Two of the most commonly prescribed new antiepileptic drugs as add-on therapy for patients with chronic refractory epilepsies are topiramate and levetiracetam. In regulatory trials, both drugs were characterized as very promising new antiepileptic drugs. However, results from these highly controlled short-term clinical trials cannot simply be extrapolated to everyday clinical practice, also because head-to-head comparisons are lacking. Therefore, results from long-term open label observational studies that compare two or more new AEDs are crucial to determine the long-term performance of competing new antiepileptic drugs in clinical practice. METHOD We analyzed all patients referred to a tertiary epilepsy centre who had been treated with topiramate from the introduction of the drug in spring 1993 up to a final assessment point mid-2002 and all patients who had been treated with LEV in the same centre from the introduction of the drug in early 2001 up to a final assessment point end-2003 using a medical information system. RESULTS Three hundred and one patients were included for levetiracetam and 429 patients for TPM. Retention rate after 1 year was 65.6% for LEV-treated patients and 51.7% for TPM-treated patients (p=0.0015). Similarly, retention rates for LEV were higher at the 24-month mark: 45.8% of LEV-treated patients and 38.3% of TPM-treated patients were still continuing treatment (p=0.0046). Adverse events led to drug discontinuation in 21.9% of TPM-treated patients compared to 6.0% of LEV-treated patients (p<0.001). The number of patients discontinuing treatment because of lack of efficacy was similar for both groups. Seizure freedom rates varied between 11.6 and 20.0% for TPM and between 11.1 and 14.3% for LEV per 6-months interval. Several important AED specific adverse events leading to drug discontinuation were identified, including neurocognitive side effects from TPM and mood disorders from LEV. CONCLUSION The retention rate for LEV is significantly higher than for TPM. LEV had a more favourable side effect profile than TPM with comparable efficacy. Patients on TPM discontinued treatment mainly because of neurocognitive side effects. In the treatment with LEV, the effects on mood must not be underestimated.

SUDEP in the Netherlands: A retrospective study in a tertiary referral center

OBJECTIVE To evaluate risk factors for sudden and unexpected death in epilepsy (SUDEP) in a high-risk population, i.e. patients treated in a Dutch tertiary referral center for epilepsy. METHODS All patients who died between January 1999 and April 2004 while under treatment of the epilepsy center were identified. Based on clinical data, deaths were classified as definite, probable, possible or non-SUDEP. Potential risk factors were compared in SUDEP cases and non-SUDEP cases. RESULTS SUDEP incidence was 1.24 per 1000 patient years. SUDEP patients died at a younger age than patients from the control group of non-SUDEP deaths with epilepsy and had an earlier onset of epilepsy. However, the frequently mentioned factors in previous studies, i.e. male sex, generalized tonic-clonic seizures, high seizure frequency, specific AEDs, polytherapy with several AEDs, mental retardation, psychiatric illness and psychotropic comedication, were not found to be correlated with SUDEP. CONCLUSIONS Even in this high-risk population of patients with refractory epilepsy, treated in a tertiary referral center, SUDEP is not a frequently occurring phenomenon. Specific risk factors could not be identified within an already high-risk population.

Adjustment of treatment increases quality of life in patients with epilepsy: a randomized controlled pragmatic trial

Background and purpose:  Complaints about side‐effects of antiepileptic drugs (AEDs) may be overlooked in clinical practice. We assessed the value and risks of an active intervention policy for reported complaints in a randomized controlled pragmatic trial.

Psychological characteristics of patients with newly developed psychogenic seizures

Objectives: To assess psychopathological symptoms and history of childhood trauma in patients with newly developed psychogenic seizures. Methods: Using validated scales, 178 patients from the general population diagnosed with newly developed seizures were assessed, at a point in time when the nature of their seizures was yet unknown to either doctors or patients. After standardised neurological examination, 138 patients were diagnosed with non-psychogenic seizures (NPS), while 40 patients were found to have psychogenic seizures (PS). To evaluate possible differences between the genders and the diagnostic groups, univariate analyses of variance were done. Results: PS patients reported significantly more comorbid psychopathological complaints, dissociative experiences, anxiety, and self-reported childhood trauma than NPS patients. In addition, PS patients had lower quality of life ratings than NPS patients. These effects were not modulated by gender. Conclusions: The results of the present study indicate that patients with newly developed PS constitute a group with complex psychopathological features that warrant early detection and treatment.

Status epilepticus during vigabatrin treatment: a report of three cases

Vigabatrin (gamma-vinyl-GABA or GVG) is an irreversible inhibitor of gamma-aminobutyric acid transaminase (GABA-T), which is an enzyme responsible for gamma-aminobutyric acid (GABA) catabolism. Inhibition of GABA catabolism increases brain concentration of GABA, a neural inhibitor. GVG has been found to be a potent new anti-epileptic drug, especially in the treatment of refractory epilepsy, in particular of complex partial seizures. Three patients who developed a severe status epilepitus while on GVG treatment are reported. A possible proconvulsive effect of GVG is hypothesized, which might result from disinhibition in the nigro-collicular pathway due to increased GABA-levels.