Andrew C.F. Hui

A randomized controlled trial of surgery vs steroid injection for carpal tunnel syndrome

Background: Decompressive surgery and steroid injection are widely used forms of treatment for carpal tunnel syndrome (CTS) but there is no consensus on their effectiveness in comparison to each other. The authors evaluated the efficacy of surgery vs steroid injection in relieving symptoms in patients with CTS. Methods: The authors conducted a randomized, single blind, controlled trial. Fifty patients with electrophysiologically confirmed idiopathic CTS were randomized and assigned to open carpal tunnel release (25 patients) or to a single injection of steroid (25 patients). Patients were followed up at 6 and 20 weeks. The primary outcome was symptom relief in terms of the Global Symptom Score (GSS), which rates symptoms on a scale of 0 (no symptoms) to 50 (most severe). Nerve conduction studies and grip strength measurements were used as secondary outcome assessments. Results: At 20 weeks after randomization, patients who underwent surgery had greater symptomatic improvement than those who were injected. The mean improvement in GSS after 20 weeks was 24.2 (SD 11.0) in the surgery group vs 8.7 (SD 13.0) in the injection group (p < 0.001); surgical decompression also resulted in greater improvement in median nerve distal motor latencies and sensory nerve conduction velocity. Mean grip strength in the surgical group was reduced by 1.7 kg (SD 5.1) compared with a gain of 2.4 kg (SD 5.5) in the injection group. Conclusion: Compared with steroid injection, open carpal tunnel release resulted in better symptomatic and neurophysiologic outcome but not grip strength in patients with idiopathic carpal tunnel syndrome over a 20-week period.

Neurotoxicity induced by beta-lactam antibiotics: from bench to bedside

Central nervous system toxicity following administration of beta-lactam antibiotics, of which penicillin is the prototype, is a potential cause of morbidity and mortality. In recent years, important advances have been made in the pathogenesis of antibiotic-related neurotoxicity. This review focuses on the experimental and clinical aspects of neurotoxicity caused by beta-lactam antibiotics. The purpose is to provide an update on the pathogenesis, mechanism, and clinical manifestations of the neurotoxicity, along with an overview of the relationship between antibiotic structure and convulsive action. In particular, some of the prevailing ideas about pathogenesis are highlighted, including theories of the mechanism of pathogencity. A better understanding of antibiotic-related neurotoxicity, as derived from animal models and human clinical experience, would be of value in facilitating more efficient and safer use of antimicrobial compounds.

Association between ABCB1 C3435T polymorphism and drug-resistant epilepsy in Han Chinese.

There is accumulating evidence to suggest that overexpression of efflux drug transporters at the blood-brain barrier, by reducing antiepileptic drug (AED) accumulation in the seizure foci, contributes to drug resistance in epilepsy. P-glycoprotein, encoded by the ABCB1 gene, is the most studied drug transporter. There are conflicting data as to whether the CC genotype of the ABCB1 3435C>T polymorphism is associated with drug resistance in Caucasian patients with epilepsy. We investigated this association in ethnic Chinese. ABCB1 3435C>T was genotyped in 746 Han Chinese patients with epilepsy and 179 controls. Patients with drug-resistant epilepsy were more likely to have the TT genotype compared with those with drug-responsive epilepsy (16.7% vs 7.4%, odds ratio=2.5, 95% confidence interval=1.4-4.6, P=0.0009). Our results contrast with those of studies of Caucasians, and highlight the complexity of the possible role of this polymorphism in AED response in different ethnic populations.

Local vs systemic corticosteroids in the treatment of carpal tunnel syndrome

The authors compared the effectiveness of low-dose, short-term oral prednisolone vs local methylprednisolone injection in a prospective, double-blinded, parallel treatment study of carpal tunnel syndrome (CTS). A single injection of 15 mg methylprednisolone resulted in significant improvement in global symptom scores over a 12-week period. This study demonstrated the superiority of local steroid injection to oral steroid in the treatment of CTS.

Bacterial meningitis in Hong Kong: 10-years’ experience

OBJECTIVE We studied the etiology, clinical features and outcome of patients with bacterial meningitis from an urban Chinese city over a 10-years period. METHODS We reviewed the files of all persons aged 15-years old or above diagnosed with community-acquired bacterial meningitis from a regional hospital. The clinical findings, relevant laboratory and imaging results as well as outcome were recorded in cases with microbiological evidence of meningitis. Neurosurgical and pediatric patients were excluded. RESULTS Sixty-five patients between the ages of 15 and 86 years of age (mean 52 years) were identified of whom 18 (28%) died. The four most common causes were Mycobacteria tuberculosis (46%), Streptococcus pneumoniae (11%), Streptococcus suis (9%) and Klebsiella pneumoniae (8%). Neisseria meningitidis and Haemophilus influenzae were rare pathogens. The annual incidence of community-acquired bacterial meningitis was 1.27/100,000 adults. Delay in treatment was associated with a poorer prognosis (p<0.001, OR=38.84, CI=7.33-205.80). CONCLUSION The causative organisms found in this region of China differ from that reported from Europe and the US; tuberculous meningitis is the most common cause of bacterial meningitis.

Prognosis following Postanoxic Myoclonus Status epilepticus

Prediction of outcome after cardiac arrest has important ethical and socioeconomic implications. In general, delay in recovery of neurological function is associated with a worse prognosis. The presence of myoclonic seizures early after anoxia has been identified as a poor prognostic factor. We report a series of patients who developed postanoxic myoclonus status epilepticus (MSE), which was defined as continuous myoclonic seizure activity lasting 30 min or more. The results from 18 patients were retrieved, 11 men and 7 women, age ranging from 29 to 90 years. Myoclonus developed a mean of 11.7 h after cardiac arrest, persisting for a mean of 60.5 h. Sixteen (89%) died following MSE and the 2 survivors were highly dependent or remained in a persistent vegetative state, supporting the view that prognosis is poor in this condition.

Status epilepticus in Hong Kong Chinese: aetiology, outcome and predictors of death and morbidity

The majority of patients with epilepsy live in developing countries but there is limited information on status epilepticus (SE) from these regions. We evaluated the clinical profile and predictors of poor outcome in a group of Chinese patients with SE. Patients with SE were ascertained from the medical, intensive care and emergency departments of a large urban hospital from 1996 to 2001. Factors for poor outcome, defined as death or morbidity as measured by deterioration in functional status using the Glasgow Outcome Score were analysed in a multivariate logistic regression model. A total of 107 episodes of SE occurring in Chinese patients were studied. The three most common underlying causes were cerebrovascular disease, metabolic derangement and anti-convulsant withdrawal but alcohol-related SE was infrequent. Twenty-six percent had worsened functional ability and the mortality rate was 16%. Predictors of poor outcome were older age (odds ratio (OR)=1.04, 95% CI 1.01-1.07), delay in treatment (OR=3.52, 95%CI 1.01-12.18), SE due to cerebrovascular disease (OR=9.73, 95% CI 1.58-59.96) and CNS infection (OR=30.27, 95% CI 3.14-292.19).

Cerebral microbleeds and white matter changes in patients hospitalized with lacunar infarcts

Abstract.Microbleeds (MBs) detected by gradient-echo T2*-weighted MRI (GRE-T2*),white matter changes and lacunar infarcts may be regarded as manifestations of microangiopathy. The establishment of a quantitative relationship among them would further strengthen this hypothesis. We aimed to investigate the frequency and the number of MBs in patients hospitalized with lacunar infarcts and their quantitative relationship with the severity of white matter changes (WMC) and the number of old lacunar infarcts. We performed a hospital-based survey of patients with acute lacunar infarct. Eighty-two consecutive Chinese patients with acute lacunar infarcts on diffusion-weighted imaging were recruited in 2002. The number of MBs, number of old lacunar infarcts on T2-weighted imaging and the severity of WMC on MRI on admission were recorded. MBs were detected in 22 (27%) patients. The number of MBs ranged from 1 to 42 (mean 6.59, median 3). Advancing age and previous transient ischemic attacks or cerebrovascular accidents (TIA/CVA) were more common in patients with MBs than those without. There were significant correlations among the number of MBs, extent of WMC and number of lacunar infarcts: lacunar infarcts and MBs (r = 0.297, p = 0.007); lacunar infarct and WMC (r = 0.331, p = 0.002); WMC and MBs (r = 0.522, p < 0.0001). In conclusion, linear associations exist among MBs, WMC and lacunar infarcts. Our results suggest that all three may have a shared pathogenesis such as advanced microangiopathy.

The validity and reliability of chinese frontal assessment battery in evaluating executive dysfunction among Chinese patients with small subcortical infarct.

Objectives:Frontal Assessment Battery (FAB) is a valid and reliable screening test for evaluating executive dysfunction among whites with frontal and subcortical degenerative lesions. We studied the properties of a Chinese version of FAB (CFAB) in evaluating executive dysfunction among Chinese stroke patients with small subcortical infarct. Methods:Concurrent validity was evaluated using Wisconsin Card Sorting Tst (WCST) and Mattis Dementia Rating Scale–Initiation/Perseveration Subset (MDRS I/P) among 41 controls and 30 stroke patients with small subcortical infarct. Discriminant validities of CFAB and its subitems were compared with those of Mini-Mental State Examination (MMSE). Internal consistency, test-retest, and interrater reliability of CFAB were evaluated. Results:The CFAB had low to good correlation with various executive measures: MDRS I/P (r = 0.63, p < 0.001), number of category completed (r = 0.45, p < 0.001), and number of perseverative errors (r = −0.37, p < 0.01) of WCST. Among the executive measures, only number of category completed had significant but small contribution (6.5%, p = 0.001) to the variance of CFAB. A short version of CFAB using three items yielded higher overall classification accuracy (86.6%) than that of CFAB full version (80.6%) and MMSE (77.6%). Internal consistency (alpha = 0.77), test-retest reliability (rho = 0.89, p < 0.001), and interrater reliability (rho = 0.85, p < 0.001) of CFAB were good. Conclusion:Although CFAB is reliable, it is only moderately valid in evaluating executive dysfunction among Chinese stroke patients with small subcortical infarct. The clinical use of CFAB in the evaluation of executive dysfunction among this group of patients cannot be recommended at this stage.

Recurrence after a first untreated seizure in the Hong Kong Chinese population.

Summary:  Purpose: There is wide variation in the reported prognosis after a first unprovoked generalized tonic‐clonic convulsion and in the risk factors that are associated with recurrence. Estimates for the risk of recurrence range from 26 to 71%. We investigated the likelihood of a second attack in Hong Kong Chinese patients.