Low incidence of neurological recurrent side-effects following COVID-19 reimmunization

BACKGROUND

Individuals who suffered a neurological adverse event after the Coronavirus disease (COVID-19) vaccine could hesitate and defer reimmunization.

AIM

We examine the risk of recurrence following reimmunization among patients who developed a neurological event after the first dose of the COVID-19 mRNA vaccine.

DESIGN

Observational study.

METHODS

Individuals who developed an adjudicated neurological adverse event (based on Brighton Collaboration criteria) within 6 weeks of the first dose of the COVID-19 vaccine requiring hospitalization were enrolled into a multicenter national registry in Singapore. Neurological recurrence, defined by the development of another neurological event within 6 weeks of the second vaccine dose, was reviewed. Clinical characteristics were compared between patients who chose to proceed or withhold further vaccination, and between those who received timely (3-6 weeks) or delayed (>6 weeks) reimmunization.

RESULTS

From 235 patients (median age, 67 years; 63% men) who developed an adjudicated neurological event after their first dose of mRNA vaccine between 30 December 2020 and 20 April 2021, 181 (77%) chose to undergo reimmunization. Those who decided against reimmunization were older (median age, 74 vs. 66 years) and had greater physical disability following their primary neurological event (46% vs. 20%, P < 0.001). Patients who suffered greater physical disability were three times more likely to delay their reimmunization (odds ratio 3.36, 95% confidence interval: 1.76-6.40). Neurological recurrence was observed in only four individuals (three with seizures and one with myasthenia gravis exacerbation).

CONCLUSIONS

A prior neurological event should not necessarily preclude reimmunization and the decision to proceed with reimmunization should consider the overwhelming benefits conferred by vaccination toward ending this pandemic.

Incidence of Cerebral Venous Thrombosis Following SARS-CoV-2 Infection vs mRNA SARS-CoV-2 Vaccination in Singapore

IMPORTANCE

Reports of cerebral venous thrombosis (CVT) after messenger RNA (mRNA)-based SARS-CoV-2 vaccination has caused safety concerns, but CVT is also known to occur after SARS-CoV-2 infection. Comparing the relative incidence of CVT after infection vs vaccination may provide a better perspective of this complication.

OBJECTIVE

To compare the incidence rates and clinical characteristics of CVT following either SARS-CoV-2 infection or mRNA-based SARS-CoV-2 vaccines.

DESIGN, SETTING, AND PARTICIPANTS

Between January 23, 2020, and August 3, 2021, this observational cohort study was conducted at all public acute hospitals in Singapore, where patients hospitalized with CVT within 6 weeks of SARS-CoV-2 infection or after mRNA-based SARS-CoV-2 vaccination (BNT162b2 [Pfizer-BioNTech] or mRNA-1273 [Moderna]) were identified. Diagnosis of SARS-CoV-2 infection was based on quantitative reverse transcription-polymerase chain reaction or positive serology. National SARS-CoV-2 infection data were obtained from the National Centre for Infectious Disease, Singapore, and vaccination data were obtained from the National Immunisation Registry, Singapore.

EXPOSURES

SARS-CoV-2 infection or mRNA-based SARS-CoV-2 vaccines.

MAIN OUTCOMES AND MEASURES

Clinical characteristics, crude incidence rate (IR), and incidence rate ratio (IRR) of CVT after SARS-CoV-2 infection and after mRNA SARS-CoV-2 vaccination.

RESULTS

Among 62 447 individuals diagnosed with SARS-CoV-2 infections included in this study, 58 989 (94.5%) were male; the median (range) age was 34 (0-102) years; 6 CVT cases were identified (all were male; median [range] age was 33.5 [27-40] years). Among 3 006 662 individuals who received at least 1 dose of mRNA-based SARS-CoV-2 vaccine, 1 626 623 (54.1%) were male; the median (range) age was 50 (12-121) years; 9 CVT cases were identified (7 male individuals [77.8%]; median [range] age: 60 [46-76] years). The crude IR of CVT after SARS-CoV-2 infections was 83.3 per 100 000 person-years (95% CI, 30.6-181.2 per 100 000 person-years) and 2.59 per 100 000 person-years (95% CI, 1.19-4.92 per 100 000 person-years) after mRNA-based SARS-CoV-2 vaccination. Six (66.7%) received BNT162b2 (Pfizer-BioNTech) vaccine and 3 (33.3%) received mRNA-1273 (Moderna) vaccine. The crude IRR of CVT hospitalizations with SARS-CoV-2 infection compared with those who received mRNA SARS-CoV-2 vaccination was 32.1 (95% CI, 9.40-101; P < .001).

CONCLUSIONS AND RELEVANCE

The incidence rate of CVT after SARS-CoV-2 infection was significantly higher compared with after mRNA-based SARS-CoV-2 vaccination. CVT remained rare after mRNA-based SARS-CoV-2 vaccines, reinforcing its safety.

Acute Ischemic Stroke During the Convalescent Phase of Asymptomatic COVID-2019 Infection in Men

IMPORTANCE

Acute ischemic stroke (AIS) is a known neurological complication in patients with respiratory symptoms of COVID-19 infection. However, AIS has not been described as a late sequelae in patients without respiratory symptoms of COVID-19.

OBJECTIVE

To assess AIS experienced by adults 50 years or younger in the convalescent phase of asymptomatic COVID-19 infection.

DESIGN, SETTING, AND PARTICIPANTS

This case series prospectively identified consecutive male patients who received care for AIS from public health hospitals in Singapore between May 21, 2020, and October 14, 2020. All of these patients had laboratory-confirmed asymptomatic COVID-19 infection based on a positive SARS-CoV-2 serological (antibodies) test result. These patients were individuals from South Asian countries (India and Bangladesh) who were working in Singapore and living in dormitories. The total number of COVID-19 cases (54 485) in the worker dormitory population was the population at risk. Patients with ongoing respiratory symptoms or positive SARS-CoV-2 serological test results confirmed through reverse transcriptase-polymerase chain reaction nasopharyngeal swabs were excluded.

MAIN OUTCOMES AND MEASURES

Clinical course, imaging, and laboratory findings were retrieved from the electronic medical records of each participating hospital. The incidence rate of AIS in the case series was compared with that of a historical age-, sex-, and ethnicity-matched national cohort.

RESULTS

A total of 18 male patients, with a median (range) age of 41 (35-50) years and South Asian ethnicity, were included. The median (range) time from a positive serological test result to AIS was 54.5 (0-130) days. The median (range) National Institutes of Health Stroke Scale score was 5 (1-25). Ten patients (56%) presented with a large vessel occlusion, of whom 6 patients underwent intravenous thrombolysis and/or endovascular therapy. Only 3 patients (17%) had a possible cardiac source of embolus. The estimated annual incidence rate of AIS was 82.6 cases per 100 000 people in this study compared with 38.2 cases per 100 000 people in the historical age-, sex-, and ethnicity-matched cohort (rate ratio, 2.16; 95% CI, 1.36-3.48; P < .001).

CONCLUSIONS AND RELEVANCE

This case series suggests that the risk for AIS is higher in adults 50 years or younger during the convalescent period of a COVID-19 infection without respiratory symptoms. Acute ischemic stroke could be part of the next wave of complications of COVID-19, and stroke units should be on alert and use serological testing, especially in younger patients or in the absence of traditional risk factors.

Neurology of COVID-19 in Singapore

PURPOSE

To describe the spectrum of COVID-19 neurology in Singapore.

METHOD

We prospectively studied all microbiologically-confirmed COVID-19 patients in Singapore, who were referred for any neurological complaint within three months of COVID-19 onset. Neurological diagnoses and relationship to COVID-19 was made by consensus guided by contemporaneous literature, refined using recent case definitions.

RESULTS

47,572 patients (median age 34 years, 98% males) were diagnosed with COVID-19 in Singapore between 19 March to 19 July 2020. We identified 90 patients (median age 38, 98.9% males) with neurological disorders; 39 with varying certainty of relationship to COVID-19 categorised as: i) Central nervous system syndromes-4 acute disseminated encephalomyelitis (ADEM) and encephalitis, ii) Cerebrovascular disorders-19 acute ischaemic stroke and transient ischaemic attack (AIS/TIA), 4 cerebral venous thrombosis (CVT), 2 intracerebral haemorrhage, iii) Peripheral nervous system-7 mono/polyneuropathies, and a novel group, iv) Autonomic nervous system-4 limited dysautonomic syndromes. Fifty-one other patients had pre/co-existent neurological conditions unrelated to COVID-19. Encephalitis/ADEM is delayed, occurring in critical COVID-19, while CVT and dysautonomia occurred relatively early, and largely in mild infections. AIS/TIA was variable in onset, occurring in patients with differing COVID-19 severity; remarkably 63.2% were asymptomatic. CVT was more frequent than expected and occurred in mild/asymptomatic patients. There were no neurological complications in all 81 paediatric COVID-19 cases.

CONCLUSION

COVID-19 neurology has a wide spectrum of dysimmune-thrombotic disorders. We encountered relatively few neurological complications, probably because our outbreak involved largely young men with mild/asymptomatic COVID-19. It is also widely perceived that the pandemic did not unduly affect the Singapore healthcare system.

Management of Status Epilepticus

Status epilepticus is due to a range of insults to the central nervous system and results in significant mortality rates, especially in the elderly. We review the current management of this disorder in light of the latest developments from recent trials and guidelines. Important principles in management includes early recognition of status epilepticus, identification of the underlying cause and prompt treatment to terminate seizures and reduce complications. The differentiation diagnosis, role of electroencephalographic monitoring and different treatment regimes are examined.

Gabapentin for the treatment of carpal tunnel syndrome: a randomized controlled trial

OBJECTIVE

Based on its efficacy in treating neuropathic pain, gabapentin may be effective for the treatment of carpal tunnel syndrome (CTS). The purpose of this study was to evaluate the efficacy of gabapentin for symptom relief in CTS.

METHODS

We conducted a randomized, double-blinded, placebo-controlled trial recruiting patients with newly diagnosed idiopathic CTS of more than a period of three months. Diagnosis was based on characteristic symptoms with electrophysiological confirmation. Patients were randomly assigned to an active group receiving gabapentin (starting dose 300 mg once daily to a target of 900 mg daily) or a placebo group. Primary end-point was the global symptom score (GSS), which was measured at baseline, two, and eight weeks.

RESULTS

There was no significant difference in baseline variables between the two treatment groups. Hundred and forty patients were enrolled in the study, of whom 71 were randomly assigned to gabapentin group and 69 assigned to placebo group. Both gabapentin and placebo produced significant improvement in symptoms at two and eight weeks. The GSS at 2 and 8 weeks was 16.4 (SD 9.4) and 13.4 (SD 9.7), respectively, in the active group versus 14.9 (SD 9.0) and 12.5 (SD 8.9) in the control group (P < 0.01). But by eight weeks, the mean reduction in symptom severity of patients on gabapentin [-10.4 (SD 10.8)] was not significant when compared with placebo [-8.7 (SD 8.1), P < 0.39]. Adverse events were not severe and included dizziness, somnolence, and headache.

CONCLUSIONS

Gabapentin did not produce a significant reduction in symptom severity compared with placebo over an eight-week period.

Agreement between initial and final diagnosis of first seizures, epilepsy and non-epileptic events: a prospective study

BACKGROUND

Differentiating between first seizure, epilepsy and a non-epileptic event is a challenging clinical exercise for many physicians as it may lead to different therapeutic implications. This study aims to investigate the agreement between the initial diagnosis at the accident and emergency (A&E) department and the final diagnosis following inpatient neurological evaluation of seizure disorders.

METHOD

A prospective observational study between April 2004 and June 2005 in a regional hospital in Hong Kong recruited 1701 patients from the A&E to neurology/medical wards with initial diagnoses/labels matching any one of 12 predefined keywords which were categorised as either "seizure specific" or "non-specific".

RESULTS

Among the 1170 patients with "non-specific" initial diagnoses/labels, 58 (5%) were finally diagnosed as having had a first seizure or epilepsy. Among 531 patients with "seizure specific" initial diagnoses/labels, 27 (5.1%) were subsequently diagnosed as having had non-epileptic events. The kappa value for agreement between the initial and final diagnosis was 0.88. Of the 154 patients with a final diagnosis of first seizure, 34 (22%) had "non-specific" initial labels. Among these patients, components of the evaluation contributing to revision of diagnosis included retrieval of witness accounts (47%), epileptiform discharges on EEG (47%), short term monitoring in patients suspected of acute symptomatic seizures (28%) and panel discussion of cases (22%).

CONCLUSION

There was generally a high degree of agreement between the initial and final diagnosis, but first seizures were often missed initially. Careful history taking, judicious use of EEG, selective short term monitoring and liaison with specialists are important in reaching an accurate diagnosis.

Single vs. two steroid injections for carpal tunnel syndrome: a randomised clinical trial

We investigated the efficacy of a single vs. double steroid injections in the treatment of carpal tunnel syndrome (CTS) in a randomised double-blind controlled trial. Patients with idiopathic CTS were randomised into (i) one group receiving a baseline methylprednisolone acetate injection plus a saline injection 8 weeks later and (ii) a second group receiving methylprednisolone acetate injection at baseline and at 8 weeks. The primary outcome was the Global Symptom Score (GSS). Forty patients were recruited. By 40 weeks, the mean GSS improved from 25.6 to 14.1 in the single-injection group whereas from 26.7 to 12.6 in the reinjection group, but there was no significant difference in GSS between the two groups (p = 0.26). There were also no significant differences in terms of electrophysiological and functional outcomes. The results suggest that an additional steroid injection confers no added benefit to a single injection in terms of symptom relief.

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.

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.

Clinical and electrophysiological features in Chinese patients with Kennedy’s disease

Kennedy's disease is a X-linked neuromuscular disorder caused by an expanded trinucleotide repeat in the androgen receptor gene. To ascertain the clinical diagnosis of Kennedy's disease in a Chinese population, we used a rapid, accurate PCR-based sizing method for the CAG repeat allelotype. The clinical and electrophysiological features of affected patients are described. The CAG repeats ranged from 43 to 53 and were inversely correlated with the age of onset (r = -0.63; P < 0.005).

Mechanisms of antibiotic neurotoxicity in renal failure

Neurological complications of antibiotics are relatively common in renal failure. Central nervous system neurotoxicity due to penicillin and beta-lactam antibiotics is best documented with fewer accounts of ototoxicity, peripheral nerve toxicity and neuromuscular blockade. In the context of risk stratification, the goal of this review is to explore the mosaic of factors in renal impairment that may contribute to susceptibility to antibiotic neurotoxicity. Improved knowledge of the pathogenesis of these formidable adverse events among the renal failure subjects should help prevent antibiotic neurotoxicity in the future.

Epilepsy in Hong Kong: a literature review

OBJECTIVE

To review data on the causes, clinical features, and management of patients with epilepsy in Hong Kong.

DATA SOURCES

MEDLINE and Chinese Current Medical Contents were used to search the literature. A manual search of the Hong Kong Medical Journal, Hong Kong Practitioner, and Chinese Medical Journal (1982-2002) was also undertaken.

STUDY SELECTION

Key words for the literature search were 'epilepsy' and 'Hong Kong'.

DATA EXTRACTION

All relevant articles in English or in Chinese language were reviewed.

DATA SYNTHESIS

Overall, disease characteristics and the response to both medical and surgical treatments of epilepsy among local Chinese patients with epilepsy was found to be comparable to that reported for patients in western countries. Knowledge of epilepsy among the general population was more limited than expected from the international literature, and attitudes to epilepsy relatively more negative, adding to the psychosocial burden for people with epilepsy.

CONCLUSION

Further research in Hong Kong on aspects of epileptology is indicated with a view to developing more innovative and effective therapy.

Influence of Emergency Room Fee on Acute Stroke Presentation in a Public Hospital in Hong Kong

A new system of emergency room fee-for-service was recently introduced at public hospitals in Hong Kong. A prospective observational study was undertaken to investigate the effects of the emergency room consultation fee system on presentation delay of acute stroke patients and evaluation of timing of patient presentation with acute stroke. We reviewed 2 specified periods (2-month interval each) before and after the consultation fee system at a public hospital. Primary outcome measures were time from onset of stroke symptoms to arrival at hospital, and predictors of such a time delay. A total of 173 subjects were recruited before institution of the consultation fee system, and 189 after inception of the new system. The mean age was 71 years. The median delay between symptom onset and arrival at hospital was 9 h. Acute ischemic stroke accounted for 91% of the stroke diagnoses. The median baseline NIHSS score measured 6. The median delay for patients before the emergency room consultation fee system was 9.7 h, compared with 8.4 h after introduction of the consultation fee (p = 0.66). At presentation, patients admitted during the consultation fee system were significantly more likely to be unconscious and be in a worse functional premorbid state. We found no difference in the frequency of general practitioner contact between the 2 study periods. Overall, univariate analyses showed that patient age, baseline NIHSS score, consciousness level upon arrival at the emergency department and premorbid ambulatory status were significant factors associated with the timing of presentation after acute stroke. A multivariate linear regression model demonstrated two independent factors: patient age younger than 70 years was independently related to presentation delay, whereas severity of stroke as indicated by unconsciousness upon arrival was associated with shorter delay. While we demonstrated no delays in acute stroke presentation accrued from enactment of the emergency room fee, physicians should endeavor to further explore strategies of reducing the late presentation of acute stroke.

Long-term outcome of carpal tunnel syndrome after conservative treatment

The purpose of this study was to investigate the long-term prognosis of patients with carpal tunnel syndrome (CTS). We prospectively followed-up patients with CTS for 80 weeks. Thirty cases had been treated with a single injection of methylprednisolone acetate and another 30 with a 10-day course of prednisolone. At the end of the follow-up period, there were no significant differences in symptoms as measured by global symptom score and in the proportion of patients who progressed to decompressive surgery. Few patients who were not operated on (11.4%) remain asymptomatic.

Cognitive impairment and functional outcome after stroke associated with small vessel disease

OBJECTIVES

Although stroke associated with small vessel disease (SSVD) can induce both motor and cognitive impairment, the latter has received less attention. We aimed to evaluate the frequency of the varying severity levels of cognitive impairment, the determinants of severe cognitive impairment, and the association of cognitive impairment with functional outcome after SSVD.

METHODS

Consecutive patients admitted to hospital because of SSVD were assessed at 3 months after stroke. We performed a semi-structured clinical interview to screen for cognitive symptoms. Severity of cognitive symptoms was graded according to the Clinical Dementia Rating Scale (CDR). Performance on psychometric tests (Mini-Mental State Examination, Alzheimer's Disease Assessment Scale (cognition subscale), Mattis Dementia Rating Scale (initiation/perseverence subscale; MDRS I/P)) of patients of different CDR gradings was compared with that of 42 healthy controls. Basic demographic data, vascular risk factors, stroke severity (National Institute of Health Stroke Scale; NIHSS), pre-stroke cognitive decline (Informant Questionnaire on Cognitive Decline in the Elderly; IQCODE), functional outcome (Barthel index; BI), Instrumental Activities Of Daily Living; IADL), and neuroimaging features (site of recent small infarcts, number of silent small infarcts, white matter changes) were also compared among the groups. Regression analyses were performed to find predictors of severe cognitive impairment and poor functional outcome.

RESULTS

Among the 75 included patients, 39 (52%) complained of cognitive symptoms. The number of patients in each CDR grading was as follows: 39 (52%) had a CDR of 0, 26 (34.7%) had a CDR of 0.5, 10 (13.3%) had a CDR of > or =1. Pre-stroke IQCODE and previous stroke predicted CDR> or =1. The NIHSS was associated with more impaired BI. The NIHSS and MDRS I/P contributed most to impaired IADL.

CONCLUSIONS

Half of the patients with SSVD complained of varying severity of cognitive problems 3 months after stroke. Pre-stroke cognitive decline and previous stroke predict severe cognitive impairment post stroke. Stroke severity and executive dysfunction contribute most to a poor functional outcome.

An unusual cause of carpal tunnel syndrome

Tuberculosis is an uncommon cause of carpal tunnel syndrome. We report a patient with systemic lupus erythematosus who developed hand numbness. Ultrasonic, operative and microbiological findings supported the diagnosis of median nerve compression secondary to a tuberculous abscess. The symptoms resolved with surgical excision and antituberculous chemotherapy.

Retrospective review of neurotoxicity induced by cefepime and ceftazidime

We reviewed 42 cases of cefepime-induced neurotoxicity and 12 cases of ceftazidime-induced neurotoxicity from the literature and our institution. Clinical characteristics and timing of diagnosis were examined. Common findings were confusion with temporospatial disorientation (96% of patients), myoclonus (33%), and seizures (13%). These neurologic disorders frequently are encountered in uremic and elderly patients, who often are in a confused state when they visit their physician. The risk of delayed diagnosis was greater with cefepime than ceftazidime neurotoxicity. The median interval between symptom onset and diagnosis of cefepime versus ceftazidime neurotoxicity was 5 and 3 days, respectively (p=0.005). Delayed diagnosis of cefepime neurotoxicity may be due to lack of awareness of the adverse effect. Data gathered since these two broad-spectrum antibiotics were first marketed underscore the potential for neurologic adverse events secondary to their administration. Thus, clinicians' awareness must be increased so that the time between symptom onset and diagnosis can be reduced.

Role of magnetic resonance imaging for preoperative evaluation of patients with refractory epilepsy

OBJECTIVE

To investigate the magnetic resonance imaging characteristics of patients with refractory epilepsy and the relationship to progression to surgery.

DESIGN

Prospective observational study.

SETTING

University teaching hospital, Hong Kong.

PATIENTS

Patients undergoing preoperative evaluation for epilepsy surgery.

MAIN OUTCOME MEASURE

Cranial magnetic resonance imaging findings, correlation with electroencephalographic results, and percentage of patients who were considered suitable candidates for surgery.

RESULTS

Structural abnormalities associated with refractory epilepsy in 100 consecutive patients were mesial temporal sclerosis (30%), neocortical sclerosis (23%), vascular malformation (7%), neuronal migration disorders (7%), and tumours (5%). Normal brain scans were found for 28% of patients. Fourteen of 30 (46%) patients with medial temporal lobe lesions at magnetic resonance imaging were suitable candidates for surgery compared with 8/42 (19%) patients with extrahippocampal lesions (odds ratio=3.7; 95% confidence interval, 1.3-10.6; P<0.012).

CONCLUSION

Mesial temporal sclerosis was the most common pathology in patients with refractory epilepsy. At the Prince of Wales Hospital, for patients who have undergone a basic magnetic resonance imaging protocol and surface electroencephalography, the result of cranial magnetic resonance imaging is an important determinant for whether patients will undergo surgery.

Lack of clinical utility of the Siriraj Stroke Score

BACKGROUND

The ability to distinguish between infarct and haemorrhage is essential to the management of acute cerebrovascular disease. In hospitals where emergency neuroimaging is not available, the use of stroke scores has been proposed to distinguish ischaemic from haemorrhagic stroke.

AIMS

To determine the accuracy of the Siriraj Stroke Score in distinguishing ischaemic from haemorrhagic stroke in a cohort of Chinese patients.

METHODS

We prospectively assessed and calculated the Siriraj Stroke Score from 253 patients with acute stroke. The sensitivity, specificity, positive and negative predictive values of this score were determined.

RESULTS

For cerebral haemorrhage, the sensitivity and specificity were both 90% or above, but the positive predictive value was not greater than 70%. For cerebral infarct, the sensitivity and specificity were around 80%, while the positive predictive value exceeded 90%. Analysis by plotting receiver operating characteristic curves failed to find other cut-off points that would improve the performance of the Siriraj Stroke Score.

CONCLUSIONS

Considering the inconsistent results from this study and previous studies of the Siriraj Stroke Score, we suggest that scoring systems that only require a small number of variables are unlikely to achieve the level of accuracy needed for clinical decision-making.

Discriminatory sonographic criteria for the diagnosis of carpal tunnel syndrome

OBJECTIVE

Sonographic examination of the median nerve has been suggested as a useful alternative to electrophysiologic study in the diagnosis of carpal tunnel syndrome. To determine its usefulness and the best diagnostic criterion, sonograms of patients with the disease were compared with sonograms of healthy subjects in a case-control study.

METHODS

Patients with carpal tunnel syndrome and asymptomatic controls who were matched for age and sex were enrolled and underwent sonography of the wrists. Eight separate sonographic criteria were analyzed in each wrist. Data from the patient group and the control group were compared to establish optimal diagnostic criteria for carpal tunnel syndrome, using receiver operating characteristic analytic techniques.

RESULTS

Thirty-five patients with carpal tunnel syndrome and 35 asymptomatic controls were examined. Increased cross-sectional area of the median nerve was found to be the most predictive measure of carpal tunnel syndrome, proximal to the tunnel inlet, at the tunnel inlet, and at the tunnel outlet, with significant differences between patients and controls. Using a receiver operating characteristic curve, a cut-off value >0.098 cm(2) at the tunnel inlet provided a diagnostic sensitivity of 89% and a specificity of 83%.

CONCLUSION

Sonographic measurement of the median nerve cross-sectional area is both sensitive and specific for the diagnosis of carpal tunnel syndrome.

Computed tomography evaluation in acute stroke: retrospective study

OBJECTIVE

To determine the accuracy with which 'frontline' hospital doctors interpret computed tomography brain scans.

DESIGN

Retrospective study.

SETTING

University teaching hospital, Hong Kong.

PARTICIPANTS

Medical and emergency room doctors.

MAIN OUTCOME MEASURE

Accuracy in correctly identifying features of acute stroke on 18 computed tomography brain scans.

RESULTS

Computed tomography brain scan images showing easily detectable haemorrhage and infarct were identified in 91% and 90% of scans, respectively; but difficult-to-interpret scans with subtle features of haemorrhage or infarct were only correctly identified in 46% and 45% of readings, respectively. More experienced doctors did not perform better than junior doctors (P=0.69; 95% confidence interval, -1.84 to 2.73) and the mean total score for doctors from the emergency department did not differ significantly from that of doctors from the medical department (P=0.57; 95% confidence interval, -2.98 to 1.67).

CONCLUSION

Early signs of infarct and small bleeds on computed tomography brain scans are not well recognised by doctors, regardless of clinical exposure or seniority. Ineligible patients may be treated with thrombolytic therapy as a result of such computed tomography scan misinterpretation.

Seizure recurrence in temporal lobe epilepsy

We report on a patient with clinical, electroencephalographic and radiological features of temporal lobe epilepsy, whose seizures were initially controlled with antiepileptic treatment. Five years after the onset of seizures, he developed more frequent and prolonged episodes of confusion, which were misinterpreted as secondary to temporal lobe epilepsy. Further investigation revealed the presence of hypoglycaemia and the eventual diagnosis of metastatic insulinoma.