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As a means of preventing secondary ischaemic stroke, angioplasty and stenting are considered potentially beneficial for patients with severe intracranial atherosclerotic stenosis. However, the role of stenting has been challenged since the publication of the first randomised controlled trial on Stenting versus Aggressive Medical Management for Preventing Recurrent stroke in Intracranial arterial Stenosis (SAMMPRIS). This indicated that aggressive medical management was superior to stenting using Wingspan to prevent recurrent stroke, because stenting has a high peri-procedural stroke and death rate. In this paper, we review the management of intracranial atherosclerosis, revisit the skepticism on stenting, and state our position on the topic in the form of recommendations. These are based on the prevalence of the disease in Hong Kong, the high risk of recurrent stroke despite medical therapy in the presence of haemodynamic intracranial stenosis without sufficient collaterals, an analysis of the weak points of SAMMPRIS, and results of clinical studies in Hong Kong.

Objectives: To define the role of bypass surgery and percutaneous transluminal angioplasty to manage critical limb ischaemia due to infrainguinal arterial occlusive disease., Design: Retrospective review., Setting: Regional hospital, Hong Kong., Patients: Consecutive patients treated for critical limb ischaemia, for whom data were prospectively collected in those who underwent: (i) infrainguinal percutaneous transluminal angioplasty first, or (ii) infrainguinal bypass surgery., Results: Among patients with critical lower limb ischaemia, 364 consecutive individuals having infrainguinal bypass operations and 100 having percutaneous transluminal angioplasty first were compared. The latter patients were older (77 vs 74 years, P=0.014) and had more co-morbidities but higher ankle pressure than those having bypass surgery. In the angioplasty-first group, 74% had favourable lesions (classified as TransAtlantic Inter-Society Consensus A/B). In the bypass group, operative mortality was higher (4% vs 1%, P=0.03) than that in the angioplasty-first group. Hospital mortality was comparable (8% vs 3%, P=0.15). In the bypass group, median hospital stay was longer than that in the angioplasty-first group (24 vs 4 days, P<0.001), and postoperatively they also had a higher median ankle-brachial index (0.92 vs 0.70, P<0.001) and superior long-term patency. In the bypass group, American Society of Anesthesiologists class 4 patients suffered very high operative and hospital mortality (15% and 31%, respectively). Long-term patency of percutaneous transluminal angioplasty depended on the TransAtlantic Inter-Society Consensus class of the treated lesion. Limb salvage rates at 3 years were 89% and 78% for percutaneous transluminal angioplasty first and surgical bypass, respectively (P=0.046). Long-term survival was poorer in the percutaneous transluminal angioplasty-first group (21% vs 51% at 5 years, P=0.04)., Conclusion: Infrainguinal bypass and percutaneous transluminal angioplasty are complementary. For TransAtlantic Inter-Society Consensus A and B lesions, percutaneous transluminal angioplasty should be offered first. For American Society of Anesthesiologists class 4 patients, percutaneous transluminal angioplasty should be considered first, regardless of the TransAtlantic Inter-Society Consensus class.

In this paper, a model for electromagnetic scattering of line structures is established based on high frequency approximation approach - ray tracing. This electromagnetic ray tracing (ERT) model gives the advantage of identifying each physical field that contributes to the total solution of the scattering phenomenon. Besides the geometrical optics field, different diffracted fields associated with the line structures are also discussed and formulated. A step by step addition of each electromagnetic field is given to elucidate the causes of a disturbance in the amplitude profile. The accuracy of the ERT model is also discussed by comparing with the reference finite difference time domain (FDTD) solution, which shows a promising result for a single polysilicon line structure with width of as narrow as 0.4 wavelength.

Introduction: Microalbuminuria is a marker of increased cardiovascular morbidity and mortality. It represents the earliest clinical evidence of diabetic nephropathy. Its early detection allows for implementation of individually-tailored cardiovascular risk reduction management programmes. Despite this, information on the prevalence of microalbuminuria in hypertensive patients with type 2 diabetes mellitus in Singapore is limited., Methods: The Microalbuminuria Prevalence Study (MAPS) assessed the prevalence of macroalbuminuria and microalbuminuria in consecutively-screened hypertensive adult patients with type 2 diabetes mellitus in ten Asian countries. This paper presents the results of a sub-analysis of data from patients in Singapore., Results: Singapore contributed seven percent of the overall enrolment into MAPS; a total of 499 patients were enrolled and 388 constituted the per-protocol population (patients with bacteriuria and haematuria were excluded). Overall, the prevalence of diabetic kidney disease was high. In our study population, 23.5 percent of patients had macroalbuminuria (95 percent confidence interval [CI] 21.3-25.6), and 48.5 percent of patients had microalbuminuria (95 percent CI 45.9-51.0). Only 28.1 percent (95 percent CI 25.8-30.4) of patients were normoalbuminuric. Associated factors were poor glycaemic control and poor blood pressure control., Conclusion: The high prevalence (72 percent) of microalbuminuria and macroalbuminuria found in hypertensive patients with type 2 diabetes mellitus in Singapore is a cause for concern. These findings highlight the need to screen for microalbuminuria and better manage hypertensive patients with type 2 diabetes mellitus, if we are to avoid a major increase in end-stage renal disease.

The neutralization behaviors of random and cross-linked methacrylic acid-ethyl acrylate (MAA-EA) copolymers were examined as a function of degree of neutralization (alpha) using potentiometric titration and laser light scattering techniques. The random MAA-EA copolymers exhibit a conformational transition from a compact latex particle to a swollen randomly coiled aggregate upon neutralization over a certain range of alpha. With further addition of NaOH, the swollen aggregates dissociate into several smaller clusters. This conformational change is controlled by the balance between electrostatic repulsion within ionized MAA groups and hydrophobic attraction of EA. The cross-linked MAA-EA copolymers do not undergo a drastic conformational change during neutralization. The polymer latex particles swell slightly upon neutralization, and the extent of chain expansion is proportional to MAA molar composition and inversely proportional to cross-linked density. The electrostatic Gibbs energy (DeltaG(el)) obtained from the potentiometric titration data indicates that a higher MAA portion is favorable for the deprotonization of both the random and cross-linked MAA-EA copolymers, suggesting that the dissociation is mainly dominated by polymer structure instead of the electrostatic attraction between H(+) and -COO(-). Moreover, static and dynamic light scattering results confirmed that the cross-linked latex particle exists as monodispersed hard sphere in the collapsed state, whereas in its swollen state the latex particle possesses a core-shell structure.

The binding of dodecyltrimethylammonium bromide (DoTab) to cross-linked methacrylic acid-ethyl acrylate (MAA-EA) copolymers with various MAA/EA molar ratios at different degrees of neutralization (alpha) was quantitatively studied using isothermal titration calorimetry, dynamic light scattering, surfactant selective electrode, and electrophoresis techniques. The surfactant binds to the polymers at all degrees of neutralization, but via different mechanisms. When alpha is sufficiently high, the binding is primarily electrostatic interaction between the surfactant and ionized polymer chains, which is reinforced by the micellization of electrostatically bound surfactant molecules. The saturation takes place at charge ratio ([DoTa(+)]/[ approximately COO(-)]) close to 1, indicating that the binding is a one-to-one charge neutralization between the cationic surfactant headgroups and anionic carboxylate sites of the polymers. When alpha is low, the binding of DoTab to the unneutralized polymers is driven by the hydrophobic interaction. The onset of hydrophobic binding takes place at DoTab concentration as low as 0.01 mM in 0.05 wt % polymer solution, where the saturation occurs at C(DoTab) approximately 0.19 mM and the amount of bound surfactant is approximately 0.09 mmol of DoTab/(g of polymer) at saturation concentration. The binding results in the formation of the polymer-surfactant complex. For the polymer with low MAA/EA molar ratio, the complex coagulates at a higher DoTab concentration that leads to phase separation; however, for polymers with high MAA/EA molar ratio, the complex remains dispersed and the mixture is stable even at high DoTab concentration.

Summary: We present a case of growth and spontaneous regression of a middle cerebral artery aneurysm after surgical clipping. A 36-year-old woman who presented with grade II subarachnoid haemorrhage was found to have a right middle cerebral artery aneurysm. The aneurysm was surgically clipped in view of the morphology of the aneurysm. Second clipping was performed four months later as there was re-growth of the neck of the aneurysm. Again re-growth of the aneurysm was noted five months after the second clipping. As further clipping of the aneurysm would be difficult, external and internal carotid arteries bypass was the treatment option but unfortunately, the by-pass operation was unsuccessful. Interestingly, angiogram performed after the bypass surgery revealed partial thrombosis and decreasing size of the aneurysm. Complete obliteration of the aneurysm was noted without further intervention one month after the failed by-pass surgery.

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., (Copyright 2000 S. Karger AG, Basel)

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%.

Summary: The three-dimensional Guglielmi detachable coil is a modification of the conventional Guglielmi coil. It has a unique complex structure, with alternating small and large loops at 90 degrees angle to each other during deployment. The enhanced coil complexity optimizes coil purchase on the aneurysm wall, promoting coil stability within the aneurysm sac. It may be the solution of the single catheter technique in the embolisation of wide neck aneurysms.We report our early experience in the embolisation of wide neck aneurysms using these complex coils.

Background and Purpose: An epidemic of suspected Japanese encephalitis occurred in Malaysia in 1998-1999 among pig farmers. In neighboring Singapore, an outbreak occurred among pig slaughterhouse workers. It was subsequently established that the causative agent in the outbreak was not the Japanese encephalitis virus but a previously unknown Hendra-like paramyxovirus named Nipah virus., Methods: The brain MR images of eight patients with Nipah virus infection were reviewed. All patients tested negative for acute Japanese encephalitis virus. Seven patients had contrast-enhanced studies and six had diffusion-weighted examinations., Results: All patients had multiple small bilateral foci of T2 prolongation within the subcortical and deep white matter. The periventricular region and corpus callosum were also involved. In addition to white matter disease, five patients had cortical lesions, three had brain stem involvement, and a single thalamic lesion was detected in one patient. All lesions were less than 1 cm in maximum diameter. In five patients, diffusion-weighted images showed increased signal. Four patients had leptomeningeal enhancement and four had enhancement of parenchymal lesions., Conclusion: The brain MR findings in patients infected with the newly discovered Nipah paramyxovirus are different from those of patients with Japanese encephalitis. In a zoonotic epidemic, this striking difference in the appearance and distribution of lesions is useful in differentiating these diseases. Diffusion-weighted imaging was advantageous in increasing lesion conspicuity.

A 38-year-old man presented with progressive worsening of choreiform movements. Serum biochemistry analysis did not reveal any abnormality. Magnetic resonance imaging demonstrated symmetrical caudate nucleus atrophy and generalised cerebral strophy. Huntington's disease was diagnosed in view of the clinical presentation and the characteristic imaging findings. The clinical, pathological and imaging features of this disease process are discussed.

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.

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.

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.

Background/aim of Study: Patient complaints are indications of their dissatisfaction with the service received. With increasing patient expectations, we need to address this issue for a more satisfying relationship between healthcare provider and user. The objective of this study was to analyse the basis of patients' complaints and to make recommendations to reduce its incidence., Method: This is a retrospective descriptive study of all complaints to the Family Health Service between January 1994 and December 1995. All complaints, investigations and replies to complainants were examined and analysed by the authors to determine the reasons for complaints and their justification., Results: There were 226 complaint cases out of 5,620,834 attendances in two years, giving the complaints rate of 4 per 100,000 attendances per year. The complaint rate was highest for the 20-59-year age group and lowest in the 10-19-year age group (3.7 and 2.0 per 100,000 attendances respectively). Sixty-four percent of complaints were verbal and the rest were written. Forty-seven percent of the complaints were made by relatives and 46% were self-complaints. The main reasons for complaints were related to attitude/conduct (28.8%), professional skills (17.8%), patient expectations (16.2%), waiting time (10.0%) and communication (7.8%). Forty-three percent of complaints were evaluated as justifiable, 38% not justifiable and 19% inconclusive. There were no particular sex or ethnic group differences., Conclusion: The rate of complaints in Family Health Service was low. Healthcare personnel need to pay attention to areas related to attitude/conduct, professional skills, patient expectations, waiting time and communication.

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.

The syndrome of painful legs and moving toes is an uncommon and distressing condition with pain in the feet or legs and involuntary movements of the toes. It can follow spinal cord or cauda equina trauma, lumbar radiculopathy, injury to the feet, peripheral neuropathy or without any preceding causes. Ephaptic transmission in damaged nerve roots or peripheral nerves with central reorganisation may be the underlying mechanism of the syndrome. Treatment is difficult. We report a case of this syndrome following peripheral neuropathy, with a good early response to the GABA agonists baclofen and clonazepam. The role of different GABA agonists in the treatment of this condition needs to be better defined.

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.

Fibromuscular dysplasia (FMD) of the internal carotid arteries and its relationship with focal cerebral ischaemia is unproven. This vasculopathy is often detected incidentally during a cerebral angiogram for non-ischaemic cerebral events. FMD affects the proximal one-third of the internal carotid artery in almost all cases and is bilateral in 60% to 85%, with middle-aged women affected in 85% of the cases. Ischaemic stroke has been postulated to result from severe stenosis or thrombotic occlusion at the FMD site. Cerebral embolism from FMD has rarely been reported. We report 3 young patients with acute ischaemic stroke who had FMD on cerebral angiography. They presented with a focal hemispheric stroke where the probable pathophysiology is embolism to the distal internal carotid artery from thrombus formed at the proximal FMD site. The patients were all males, with unilateral proximal internal carotid artery FMD lesions and occlusion of the internal carotid artery distally on the same side. All were extensively investigated and no other causes for stroke were found.

Two gene sequences specific for Mycobacterium tuberculosis were evaluated for the diagnosis of pulmonary tuberculous (PTB) in pleural fluid (PF), bronchoalveolar lavage fluid (BAL) and sputum (Sp). The 240 bp sequence (nts 460-700) coding for the MPB 64 protein coding gene and the 123 bp IS6110 insertion element present in multiple copies in the mycobacterial genome were amplified using the polymerase chain reaction. Fifty-nine clinical specimens were studied. The diagnosis of PTB was confirmed by positive M. tuberculosis cultures in 14 specimens, and by the presence of characteristic histological features of granuloma and Langerhan's giant cells on pleural biopsy in 3 PF specimens through cultures for M. tuberculosis were negative. The remaining 42 specimens were obtained from patient's with non-tuberculosis pulmonary infections or malignancy, and these served as negative controls. Our results showed that the IS6110 insertion element and MPB 64 gene sequence were detected in all 14 culture positive PTB cases, although detection of the latter sequence required both DNA amplification and oligonucleotide hybridization. There was however one false positive specimen with the MPB 64 detection protocol. More importantly, both the MPB 64 sequence and IS6110 insertion element protocols were unable to detect M. tuberculosis DNA in the 3 PF samples diagnosed by histological characteristics on pleural biopsy and culture negative. We conclude that DNA amplification for M. tuberculosis-specific sequences is a useful method for rapid diagnosis of PTB in culture positive specimens. However, the false negative results with TB culture negative cases of tuberculosis pleurisy, limits its usefulness for the diagnosis of tuberculous pleurisy.

Aim: DNA amplification by the polymerase chain reaction (PCR) was evaluated as a means for rapid diagnosis of tuberculous meningitis (TBM)., Methods: A 240 bp region (nts 460-700) from the MPB 64 protein coding gene specific for Mycobacterium tuberculosis (TB) was selected for amplification. Nineteen clinical samples were studied. Six were obtained from patients with TBM diagnosed by culture (4/6) or by response to therapy (2/6). The remaining 13 samples were obtained from patients with febrile seizu es (8/13), aseptic meningitis (3/13) and septic meningitis (2/13), and these served as negative controls., Results: We detected TB DNA in all the 6 CSF specimens obtained from patients with TBM. PCR alone was sufficient to detect TB DNA in 5 of these 6 samples. However, one sample was positive only when PCR was followed by oligonucleotide hybridisation. In the 2 patients whose CSF were obtained only after commencement of TB therapy, TB cultures were negative but positive on PCR nd oligoprobe labelling. The diagnosis of TBM was confirmed based on their remarkable response to therapy. Twelve of the thirteen negative controls were TB DNA negative. There was one false positive sample, which was thought to be due to TB DNA contamination., Conclusion: Taken together, our results indicate that DNA amplification using PCR, followed by oligonucleotide hybridisation offers a rapid (5 working days) means of diagnosis of TBM, provided care is taken to ensure that cross contamination of DNA samples is avoided.

The axillary artery was studied by dissection of 50 human cadavers over a two-year period. Except in one instance, the course and relations of the axillary artery of all the other cadavers conformed to the normal description found in standard textbooks of Anatomy. In the exceptional cadaver, the axillary artery of the right side showed two unique features: (1) it pursued a tortuous course and made two sharp bends, and (2) it was situated superficial, rather than deep to, the pectoralis minor muscle. Its branches and relationship to the brachial plexus were also altered. On the left side, the artery was not tortuous but was also situated in front of the pectoralis minor. The present observation has several implications: (1) such a configuration of the artery would render it more prone to kinking and hence compression; (2) surgically, it might make axillary block of the brachial plexus and block dissection of the axillary lymph nodes during radical mastectomy more difficult; (3) it is at risk during infraclavicular percutaneous cannulation of the subclavian vein for a central line insertion or for insertion of a subclavian cannula for haemodialysis.

DNA amplification of three Mycobacterium tuberculosis-specific DNA sequences by the polymerase chain reaction (PCR) were evaluated as a means for rapid diagnosis of tuberculous meningitis (TBM). The DNA sequences amplified were a 123 bp region of the IS6110 insertion elements which occur in multiple copies in the mycobacterial genome, a 240 bp region (nts 460-700) from the MPB 64 protein coding gene, and the 383 bp region of the 65 kDa heat shock protein (HSP) antigen. Twenty-seven cerebrospinal fluid (CSF) specimens were studied. Six were obtained from patients with TBM diagnosed by culture (4/6) or by the patients' response to anti-tuberculous therapy (2/6). The remaining 21 specimens were obtained from patients with febrile seizures (3/21), aseptic meningitis (3/21), septic meningitis (14/21), and cryptococcal meningitis (1/21), and these served as negative controls. Our results indicate that although the protocols involving the 3 DNA sequences were able to detect TB DNA in the 6 TBM specimens, the main drawback was their extreme sensitivity, thus giving rise to false positive results. In particular, the repeat copy sequence, IS6110, and the 65 kDa HSP gave unacceptably large numbers of false positive results (62% and 33%, respectively).

Chinese Singaporean myasthenia gravis (MG) patients are associated with three HLA haplotypes: Cw1 B46 DRB1*0901 DQB1*0303 DQA1*03, DRB1*14 DRB3*0202 DQB1*0503 DQA1*0101 and DRB1*1202 DRB3*0301 DQB1*0301 DQA1*0601. The B46 haplotype was associated with the total group of MG patients but in particular with those with younger onset, low antiacetylcholine receptor (anti-AchR) titres, with only ocular lesions and with normal thymuses. The DRB1*14 haplotype was associated with thymic hyperplasia, younger onset patients, with high anti-AchR titres and with generalised MG. The DRB1*1202 haplotype was associated with thymoma, older onset patients, ocular lesions, and mid to high anti-AchR titres.

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.

A 52-year-old Chinese female with recurrent cerebral thrombosis associated with hereditary protein S deficiency is described. The need to consider clotting disorders in young patients with no known risk factors for stroke is emphasized.

Acute mutism with paralysis of the bulbar and facial muscles following discrete bilateral internal capsular infarction is a rare stroke syndrome. We describe a 62 year-old male who suddenly became unable to speak or swallow. The paucity of facial expression and inability to voluntarily move the facial, lingual and pharyngeal muscles were persistent and contrasted with a relatively mild limb paresis which recovered. High resolution CT scan revealed infarcts in the posterior limbs of both internal capsules. It is important to recognise this stroke syndrome because of the permanence of dysarthria and dysphagia associated with it.

We describe a 30 year-old female who presented with severe orthostatic hypotension despite appropriate compensatory tachycardia on standing, following a viral infection. Clinical assessment and laboratory evaluation failed to detect other causes of her illness besides sympathotonic orthostatic hypotension. She responded to fludrocortisone and recovered completely after 3 months. We postulate that her acute reversible illness was due to a post-viral immunological response selectively affecting the alpha adrenergic receptors subserving the post-ganglionic sympathetic vasomotor fibres.

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.

Cryptococcosis is a systemic fungal disease and meningitis is the most serious complication. The purpose of this study is to define problems related to its diagnosis and treatment. This is a retrospective analysis of 25 patients admitted from January 1978 to December 1981. All patients had cryptococcal neoformans meningitis proven by culture of cerebrospinal fluid. One patient had a predisposing illness, being on immunosuppressant therapy after a renal transplant 2 years ago. A progressively severe headache of recent onset was the most striking presentation. Fever was frequently absent as a symptom. Cranial nerve palsies were commonly seen. Impairment of consciousness and areflexia signified a poor prognosis as all four patients who died early in the course of treatment were comatose and two of them were areflexic on admission. In newly suspected cases at least 3 separate lumbar punctures are recommended as initial smears or cultures may be negative. Cerebral CT scans were abnormal in 12 patients and those with cerebral oedema or hydrocephalus had a poorer prognosis. Combined amphotericin B and 5-fluorocytosine therapy was the treatment of choice. If there is no relapse 3 years after completion of treatment, patients are considered as cured. Positive smears may remain for years after completion of treatment and retreatment is only indicated if the cultures are positive. Twenty patients are alive today and none of them have relapsed. One patient had vasculitis of both anterior cerebral arteries as a result of cryptococcal meningitis.

Ammonium ions added in large quantity disappear rapidly from the reservoir of the sheep placenta perfused in situ through the umbilical vessels. Ammonium ions are removed from the reservoir of perfused sheep fetal livers of 108-141 days of conceptual age at a rate of at least 1 mumol/min/g liver. The majority appears as urea. There is little or no change in glutamine concentration. Hepatic carbamoylphosphate synthetase I, ornithine transcarbamylase, argininosuccinate synthetase, argininosuccinase and arginase are present, even at 97 days of conceptual age, in adequate amounts to account for the observed urea production. With the exception of arginase, all levels rise with fetal age. The levels in the maternal liver are comparable with those at 106 days of conceptual age. Arginase is high in the younger fetuses, falls progressively with fetal age and is very low in the mother. It is concluded that (a) the perfused placenta is permeable to ammonia and the placenta may be able to clear ammonia from the fetal circulation at a rate comparable with that of fetal liver; (b) the fetal liver converts ammonia to urea at a rate comparable with the urea production of the fetus; (c) there is virtually no glutamine production by the fetal liver; (d) adequate amounts of the enzymes of urea synthesis are present even in the immature fetal liver to account for the total urea production of the fetus, and (e) the anomalously low arginase level in the maternal liver may conserve maternal arginine, and the high levels in the younger fetuses may be related to fetal polyamine production from maternally derived arginine.

We studied monocular pattern ERG (PERG) in 10 normal subjects and a patient with optic neuritis. No clinically significant PERG could be recorded from the occluded eye with any reference (ipsilateral ear or temple, or midfrontal), indicating that cross-contamination is not present with binocular testing. Ipsilateral temple reference minimized VEP (P100/N100) contribution to the PERG N95 which occurred with ipsilateral ear or midfrontal reference. The conclusions were confirmed by results from the patient, who had marked monocular delay of a normal amplitude P100. Twenty-four subjects were tested with monocular and binocular stimulation using an ipsilateral temple reference. There were differences in PERG latencies and amplitudes although the interside amplitude ratio showed smaller differences with binocular stimulation. Increasing check size (17, 35 and 70 min) decreased P50 and N95 latencies and increased P50 amplitude.