Heparin induced thrombocytopenia.

BACKGROUND: Heparin is a widely used antithrombotic agent for treatment of ischemic cerebrovascular disease. One of its most important side-effects is thrombocytopenia which may lead to potentially life-threatening haemorrhagic and thrombotic complications. METHODS: We performed a prospective study to determine the frequency of heparin induced thrombocytopenia. Heparin induced thrombocytopenia is defined as a platelet count of less than 150 x 10(3)/mm3 or a decrease in platelet count to 30% to 50% from baseline. Daily platelet counts were obtained in 50 adult patients who were treated with the same lot of intravenous bovine heparin. Two patients (4%) developed thrombocytopenia with onset varying from four to seven days after heparin was started. In both cases, platelet counts returned to baseline levels three to five days after cessation of therapy. No ischemic or haemorrhagic complications occurred. CONCLUSION: Heparin induced thrombocytopenia is a common complication of intravenous heparin treatment. Clinicians treating patients with heparin should determine platelet counts at baseline and henceforth at regular intervals beginning from the fifth day of therapy. We recommend commencement of warfarin therapy concurrently with heparin infusion and discontinuation of heparin once warfarin has become effective. All doctors must be vigilant to this reversible common complication.

Concurrent myelitis and Guillain-Barré syndrome after varicella infection.

Myelitis and Guillain-Barré syndrome occurring concurrently after varicella infection is very rare. A 34-year-old man presented with progressive flaccid tetraparesis, facial palsy, respiratory failure, sensory loss and urinary incontinence one week after varicella infection. Clinical, imaging and electrodiagnostic studies supported the diagnosis of myelitis and Guillain-Barré syndrome. He improved with intravenous acyclovir and gammaglobulin.

Tongue deviation in acute ischaemic stroke: a study of supranuclear twelfth cranial nerve palsy in 300 stroke patients.

It is generally believed that the supranuclear innervation of the hypoglossal nucleus is bilateral and symmetrical. The aim of this work is to study the frequency and clinical characteristics of supranuclear tongue palsy in unilateral stroke. 300 patients with acute unilateral ischaemic motor strokes (excluding those in the lower brainstem) and an equal number of normal controls were studied for the presence of tongue deviation in a standardised manner. 29% of stroke patients and 5% of controls had tongue deviation (p < 0. 00001). Deviation was always to the side of the limb weakness. In patients with a history of stroke, it occurred more frequently in those with previous stroke on the contralateral side. Tongue deviation was most common in patients with clinical features of the non-lacunar stroke subtype (56%) or in those with cortical or large subcortical infarctions on brain CT scan (55 and 45%, respectively). All tongue deviations were associated with supranuclear 7th nerve palsy. Dysphagia and dysarthria occurred in 43 and 90% of patients with tongue deviation. Weakness of the arm was significantly associated with presence of tongue deviation. Tongue deviation in unilateral stroke most likely results from asymmetrical supranuclear control of the 12th cranial nerve in many individuals. The finding that it occurs relatively commonly in large (non-lacunar) infarcts and its association with dysphagia may have clinical utility.

Elimination of phenytoin in toxic overdose.

Phenytoin is widely used for the management of seizures. Fortunately overdosage with this drug is rare. We performed a prospective study to investigate the elimination kinetics of phenytoin in toxic overdose. All patients were only on phenytoin and not on other anticonvulsants. Phenytoin toxicity was defined by clinical features and correlated with drug levels. Daily phenytoin levels were obtained until they were less than or equal to 15 mcg/ml. Nine patients with age ranging from 20 to 66-years-old were recruited. Sex ratio was male:female, 5:4. Initial phenytoin levels ranged from 34 to 57.5 mcg/ml. Serum phenytoin levels of three patients remained relatively constant for 2-5 days before declining in a steady fashion. Phenytoin levels of the remaining patients declined in an almost linear manner. Regression analysis of all patients showed that the slope terms were highly significant (with low P-values) and corresponding R(2) values were close to 1. Different patients have different rates of metabolism; in seven of nine patients, levels declined between 4.6 and 5.9 mcg/ml per day. Knowledge of the rate of elimination assists the clinician in deciding on the best time to reinstitute phenytoin therapy.

Aberrant regeneration of the third nerve.

We describe three patients with aberrant regeneration of the third nerve secondary to traumatic brain injury. The full blown features of the syndrome include horizontal gaze-eyelid synkinesis, pseudo-Graefe sign, limitation of elevation and depression of the eye with retraction of the globe on attempted vertical movements, adduction of the involved eye on attempted elevation or depression, pseudo-Argyll Robertson pupil and absent vertical optokinetic response. The 'misdirection' incidence in our study is 15%.

Palatal myoclonus--a case report.

Palatal myoclonus is usually due to a brainstem or cerebellar lesion disrupting the dentato-rubro-olivary pathway. Rarely it may be caused by a cortical lesion. The precipitating factor in 70% of all cases is an infarct. We describe an unusual case of a patient with palatal myoclonus who had an old ipsilateral cerebellar infarct and a new contralateral subcortical (corona radiata) infarct. We postulate that the new infarct caused disinhibition of the old cerebellar infarct, resulting in palatal myoclonus. Magnetic resonance imaging (MRI) of the brain did not show any hypertrophy of the inferior olivary nucleus. Her myoclonus proved refractory to clonazepam, valproate and phenytoin.

Bilateral substantia nigra changes on MRI in a patient with encephalitis lethargica.

A 33-year-old woman admitted for meningoencephalitis had features of encephalitis lethargica develop on her third day of illness. She had ophthalmoplegia, akinetic mutism, and prominent extrapyramidal signs consisting of lip and hand tremors, cogwheel rigidity, and facial bradykinesia.

Paradoxical seizures in phenytoin toxicity.

Phenytoin toxicity is an uncommon problem seen in clinical practice. The predisposing factors for toxicity are hypoalbuminemia, chronic renal failure, hepatic dysfunction and drugs which interfere with phenytoin metabolism. Common manifestations of toxicity, like confusion and ataxia, are well known. A less well known phenomenon is paradoxical seizures. In this condition, seizures develop as the serum phenytoin level rises and decrease in frequency as levels drop. It may or may not be accompanied by other features of toxicity. We present three patients with paradoxical seizures; their serum phenytoin levels were 43.5 mcg/mL, 46.5 mcg/mL and 38.3 mcg/mL. In all cases, seizures were controlled by withdrawal of phenytoin and reduction of drug levels.

The neurological manifestations of Nipah virus encephalitis, a novel paramyxovirus.

A novel Hendra-like paramyxovirus named Nipah virus (NiV) was the cause of an outbreak among workers from one abattoir who had contact with pigs. Two patients had only respiratory symptoms, while 9 patients had encephalitis, 7 of whom are described in this report. Neurological involvement was diverse and multifocal, including aseptic meningitis, diffuse encephalitis, and focal brainstem involvement. Cerebellar signs were relatively common. Magnetic resonance imaging scans of the brain showed scattered lesions. IgM antibodies against Hendra virus (HeV) were present in the serum of all patients. Two patients recovered completely. Five had residual deficits 8 weeks later.

Paroxysmal kinesigenic choreoathetosis in Singapore and its relationship to epilepsy.

OBJECTIVES: To study the clinical characteristics of paroxysmal kinesigenic choreoathetosis (PKC) in our local population and its relationship to epilepsy. METHODS: We reviewed retrospectively 15 patients who were managed by neurologists in our department from 1982 to 1996. The literature was also reviewed to study the association between PKC and epilepsy. RESULTS: In our study, all the cases were idiopathic. The male to female ratio was 14:1 with all major races represented. Sixty percent of our patients suffered dystonic posturing rather than chorea, during the attacks. Twenty-one percent had a family history of a similar disorder which appeared to be of autosomal dominant inheritance. The sporadic form (79%) predominated in Singapore. One had a history of febrile fits while two had a history of epilepsy. We reviewed the available literature and found five other patients with idiopathic PKC also suffering from epilepsy. Of the 83 patients reviewed, 8% had epilepsy. This further strengthens the relationship between the two conditions. All our patients responded well to phenytoin at doses between 100 and 400 mg/day. CONCLUSION: PKC affected all three major races in our population with a high male to female ratio of 14:1. Seventy-nine percent of our cases were sporadic and 60% suffered dystonic posturing during attacks. Of the cases reviewed, 8% of patients with idiopathic PKC also had epilepsy.

Stereotactic microelectrode-guided posteroventral pallidotomy and pallidal deep brain stimulation for Parkinson's disease.

Three patients underwent stereotactic posteroventral pallidotomy, and 1 patient underwent pallidal deep brain stimulation, for medically intractable symptoms of advanced Parkinson's disease, characterized by peak-dose levodopa dyskinesias, wearing-off fluctuations, tremor, rigidity and bradykinesia. Surgery was performed stereotactically under local anaesthesia, with eventual target coordinates derived from a combination of magnetic resonance imaging (MRI), coregistration with an electronic brain atlas, intraoperative microelectrode neuronal recordings and microstimulation before lesioning or placement of a deep brain stimulator was done. Assessment was made at baseline preoperatively and at 3-month intervals postoperatively, with Unified Parkinson's Disease Rating Scale (UPDRS) and Core Assessment Program for Intracerebral Transplantation (CAPIT) scoring. All patients improved in dyskinesia, tremor, rigidity and bradykinesia contralateral to the lesion side, but also on the ipsilateral side to a lesser extent. The improvement was largely seen in the 'off' state: UPDRS by 41%, and CAPIT by 19% on the contralateral side. 'On' freezing was not helped. There were no deaths and no visual complications, but there was one complication of a delayed contralateral upper limb dystonia after pallidotomy. The 1 patient with pallidal deep brain stimulation (DBS) obtained similar improvement as those with pallidotomy. Posteroventral pallidotomy and pallidal stimulation improves all the cardinal features of Parkinson's disease, and effectively ameliorates levodopa dyskinesias.

The profile of hospitalised patients with Parkinson's disease.

The objective of this study was to provide a profile of patients with Parkinson's disease (PD) who required admission to hospital. We reviewed retrospectively all patients with PD who were admitted to our hospital in 1995. In our study, there were 260 admissions involving 173 PD patients. The average age was 74.7 years. Of these patients, 93 were males and 80 were females. There were 150 Chinese, 12 Indians, 9 Malays, and 2 of other races. The average duration of hospitalisation was 11.7 days. The main reasons for admissions were: 1) chest infections (22%), 2) falls (13%), 3) control of PD symptoms (10%), 4) general medical problems (9%) and 5) urinary dysfunction (8%). Nine per cent were classified as Hoehn and Yahr stage 2, 31% as stage 3, 31% as stage 4 and 24% as stage 5. Twenty-one per cent of our patients were first diagnosed with PD during their hospitalisation. Upon discharge, 26% required transfer to either a community hospital or nursing home. The current in-patient load of PD patients is expected to rise with the ageing population. A significant number of people within the community may have undiagnosed PD. These patients suffer multiple medical problems and need a multi-disciplinary team approach to management. Greater resources will be required to support these patients in the community.

Creutzfeldt-Jakob disease presenting with visual blurring, diplopia and visual loss: Heidenhain's variant.

Focal electroencephalographic abnormalities as described in Heidenhain's variant of Creutzfeldt-Jakob disease are uncommon. We report a 73-year-old male presenting with visual symptoms, right hemianopia and rapidly progressive dementia. Myoclonus was synchronous with generalised periodic epileptiform discharges on electroencephalography (EEG). In addition, there were periodic focal sharp waves at the left occipital region. Diffusion-weighted magnetic resonance brain images showed slightly increased signal intensity in the occipital parasagittal area, left more than right. 14-3-3 protein was detected in the cerebrospinal fluid. The patient died within 5 months of presentation.

A case of bilateral ulnar nerve palsy in a patient with traumatic brain injury and heterotopic ossification.

Heterotopic ossification after head injury may occur in the elbow joint. Rarely does this lead to entrapment of the ulnar nerve. We describe the case of a 20-year-old patient who developed heterotopic ossification 6 weeks after a traumatic brain injury. She subsequently developed bilateral ulnar nerve palsy which was confirmed by electrodiagnostic studies and treated by transposition of the ulnar nerve.

Sciatic neuropathies--a retrospective review of electrodiagnostic features in 29 patients.

Sciatic neuropathy is an uncommonly diagnosed focal mononeuropathy. We reviewed the aetiology and electrodiagnostic features of 29 patients studied at the Neurodiagnostic Laboratory, Tan Tock Seng Hospital from January 1989 to April 1995. External nerve compression was the most common cause (38%) followed by trauma (21%). Other rare causes in this series included intragluteal injections, hip surgery and diabetic mononeuropathy while 24% had uncertain aetiology. Electrodiagnostic studies showed preferential involvement of the peroneal division in 51%. Axonal loss was found in 97%. We conclude that sciatic neuropathy often mimics distal peroneal nerve dysfunction and neurophysiological studies are essential for diagnosis. Furthermore, these studies are necessary for assessing prognosis in relation to axonal loss.

Complement deficiency predisposes for meningitis due to nongroupable meningococci and Neisseria-related bacteria.

Nongroupable meningococci or bacteria related to the genus Neisseria rarely cause meningitis. Complement deficiency has been identified as a major predisposing factor for meningococcal disease. To assess whether patients with meningitis due to such strains have a complement deficiency, we studied 12 persons. Six patients had meningitis due to nongroupable strains of meningococci, and six patients had meningitis due to Moraxella species or Acinetobacter species. Inherited complement component C7 or C8 deficiency was found in two persons who had had meningitis due to nongroupable meningococci, and one C8-deficient person had had meningitis caused by Moraxella osloensis. Hypocomplementemia resulting from CSF drain-associated shunt nephritis was found in one person with meningitis due to Moraxella nonliquefaciens and in one person with meningitis due to Acinetobacter lwoffi. This rather high frequency of inherited or acquired complement deficiencies among patients with meningitis due to nongroupable meningococci, Moraxella species, and Acinetobacter species justifies the recommendation that such patients must be studied for complement deficiency.

Adult onset polymyositis/dermatomyositis: clinical and laboratory features and treatment response in 75 patients.

OBJECTIVES: To determine possible similarities and differences in clinical and laboratory features and treatment response between patients in Singapore with polymyositis (PM) and dermatomyositis (DM) and reported series. METHODS: Case records of adult patients (16 years old and above) referred to the 3 main electromyographic (EMG) laboratories in Singapore between 1 June 1986 and 31 May 1991 were reviewed if the referring diagnosis was myositis or myopathy for investigation. A computer search for adult patients with a diagnosis of PM/DM (ICD codes 710.3, 710.4, 517.8) who attended the main rheumatology and neurology centre during this period was also carried out. The criteria for PM/DM proposed by Bohan and Peter was adopted. RESULTS: The incidence of PM/DM was 7.7 cases per million population per year. There were 35 PM and 40 DM cases with a median age at diagnosis of 50.7 years (SD: 16.7) and significantly more females in the PM group (p < 0.05). At presentation, 86.7% had proximal myopathy, 34.7% had arthralgia/arthritis and 18.7% had cutaneous vasculitis. The creatine kinase level was elevated in 89.3% of patients and positive EMG and muscle biopsy in 79.4% and 76.4% respectively. Systemic lupus erythematosus was the commonest associated connective tissue disease. The percentage of patients with malignancy was higher in DM compared with PM (p < 0.01) and they were significantly older (mean age 61.8 years) (p < 0.001). Patients who achieved remission were significantly younger (mean age 46.4 years, p < 0.05). The overall mortality rate was 26.7% with infection and malignancy as the main causes of death. CONCLUSION: The results of the study suggest ethnicity does not influence the expression of PM/DM in view of the considerable similarities in frequency and clinical expression of disease in the population studied compared with series from other countries.

Transient oculomotor nerve synkinesis in non-Hodgkin's lymphoma.

A patient with large cell malignant lymphoma presented with transient left oculomotor nerve synkinesis, left trigeminal and abducens nerve palsies. Magnetic resonance imaging showed thickening of the oculomotor and trigeminal nerves characteristic of central nervous system lymphoma. To our knowledge, this is the first reported case of transient oculomoter nerve synkinesis in non-Hodgkin's lymphoma. The rapid onset and quick recovery of the synkinesis following 2 weeks of chemotherapy support the ephatic transmission theory.

Nuclear third nerve palsy and somnolence due to stroke--a case report.

We describe a 40 year-old male with a ball-cage mitral valve prosthesis who suddenly developed bilateral ptosis, bilateral dilated and unreactive pupils, right third nerve palsy, bilateral failure of vertical gaze, somnolence and mild ataxia without major motor deficits. Computed Tomography (CT) revealed bilateral thalamic infarcts in the distribution of the rostral basilar artery. Infarction in this case occurred despite adequate anticoagulation. The recognition of the entity of rostral basilar artery occlusion is important as interruption of anticoagulation may be avoided.