MyMedR

Tan CT

Neurology, 2015 Feb 10;84(6):623-5.

PMID: 25666629 DOI: 10.1212/WNL.0000000000001224

Asia is important as it accounts for more than half of the world population. The majority of Asian countries fall into the middle income category. As for cultural traditions, Asia is highly varied, with many languages spoken. The pattern of neurologic diseases in Asia is largely similar to the West, with some disease features being specific to Asia. Whereas Asia constitutes 60% of the world's population, it contains only 20% of the world's neurologists. This disparity is particularly evident in South and South East Asia. As for neurologic care, it is highly variable depending on whether it is an urban or rural setting, the level of economic development, and the system of health care financing. To help remedy the shortage of neurologists, most counties with larger populations have established training programs in neurology. These programs are diverse, with many areas of concern. There are regional organizations serving as a vehicle for networking in neurology and various subspecialties, as well as an official journal (Neurology Asia). The Asian Epilepsy Academy, with its emphasis on workshops in various locations, EEG certification examination, and fellowships, may provide a template of effective regional networking for improving neurology care in the region.

Fulltext The hot bath test among Malaysian multiple sclerosis patients

Tan CT

Med J Malaysia, 1994 Mar;49(1):68-73.

PMID: 8057994

This is a study of 13 Malaysian patients with clinically definite Multiple sclerosis (MS) subjected to a hot bath test with VEPs, BAEPs, median nerve SSEPs before and after heating. Five patients (38%) developed neurological changes with the rise in body temperature. There was an average of 0.46 new sign per patient. Four patients had motor disturbances attributed mainly to aggravation of spinal cord dysfunction. Two patients had additional visual deterioration, one patient has associated VEP change. This study shows that though Uhthoff's phenomenon has not been noted in the reports of Asian MS patients, when subjected to rigorous testing, Asian MS patients also show sensitivity to body temperature change. However, the percentage of positivity of the hot bath test is much lower than that reported for Caucasians. Thus this study shows further differences between Asian and Caucasian MS patients.

Multiple sclerosis in Malaysia

Tan CT

Arch. Neurol., 1988 Jun;45(6):624-7.

PMID: 3369969

Thirty consecutive patients from peninsular Malaysia with clinically definite multiple sclerosis were studied; 80% were ethnic Chinese, with a female-male ratio of 5:1. The average age at onset was 29.7 years, with one relapse average every 1.9 years. Optic-spinal recurrence was the most common clinical pattern of the disease, accounting for 63.3% (19/30) of the cases. All the patients had spinal cord involvement sometime during the course of the illness. The mortality was high at 36.7% (11/30), with an average duration of symptoms of 7.6 years. There was characteristic severe residual visual and motor disability. At the time of the last examination, 12 patients had bilateral optic atrophy with blindness or severe visual acuity impairment. Sixteen patients were bedridden or confined to a wheelchair. The severe motor disability reflected the severe spinal cord involvement. It was the main factor that accounted for the high mortality. The cerebral, cerebellar, and brain-stem involvements were, however, generally transient. None of the patients' had a family history of similar illness despite the average sibling size of six. There was no example of Devic's disease. The clinical pattern was closest to those patients who presented from Taiwan.

Fulltext Syndromes of ophthalmoplegia, ataxia and areflexia - case report

Tan CT

Med J Malaysia, 1981 Sep;36(3):186-7.

PMID: 7329377

Two cases of Syndromes of Ophthalmoplegia , Ataxia and Areflexia were reported. A brief discussion on its clinical feature and differential diagnosis was made.

Fulltext A family with hereditary ataxia

Tan CT

Med J Malaysia, 1980 Dec;35(2):134-8.

PMID: 7266406

An Indian family with four members having hereditary ataxia was presented. The inheritance was most likely autosomal dominant. The onset was at adult life. The main disability was cerebellar ataxia with pyramidal tract sign found at physical examination. Electroencephalography and nerve conduction study were abnormal in two cases where they were done. The clinical feature correspond to an intermediate form of hereditary ataxia.

Prognosis of patients who present with an episode of myelopathy of unknown origin in Malaysia: a retrospective study of 52 patients

Tan CT

Aust N Z J Med, 1989 Aug;19(4):297-302.

PMID: 2783084

Fifty-four per cent of 52 patients presenting to the University of Malaya Medical Centre with a myelopathy for which appropriate investigations uncovered no definite etiology, subsequently developed clinically definite or probable multiple sclerosis. In the subgroup of patients with a presentation indicative of acute/subacute transverse myelopathy, 14 or 52% also went on to develop clinically definite or probable multiple sclerosis, a far higher proportion than previously recorded in the literature. This finding is probably a further manifestation of racial difference in the behaviour of multiple sclerosis. For the group as a whole, the only factor which appeared to be associated with an increased risk of developing multiple sclerosis was female sex; 67% of 33 female patients went on to develop multiple sclerosis after a mean follow-up period of 5.5 years. Other factors such as age of onset, racial composition, level of spinal cord involvement, presence of fever and CSF finding were found not to be important.

Intracranial hypertension causing visual failure in cryptococcus meningitis

Tan CT

J Neurol Neurosurg Psychiatry, 1988 Jul;51(7):944-6.

PMID: 3204403

Thirty four patients with cryptococcal meningitis seen in the University of Malaya medical centre since 1980 were reviewed. Eleven patients had bilateral papilloedema and visual impairment but eventually survived. Seven patients had intensive aggressive measures, including shunting to reduce intracranial hypertension irrespective of ventricular size shown in CT scan, and showed substantial improvement in vision. It is concluded that papilloedema and visual failure in cryptococcal meningitis reflects raised intracranial pressure and that this should be treated vigorously.

Juvenile muscular atrophy of distal upper extremities

Tan CT

J Neurol Neurosurg Psychiatry, 1985 Mar;48(3):285-6.

PMID: 3981204

Suicide trends in Singapore, 1975-84

Tan CT

Med Sci Law, 1986 Jul;26(3):238-42.

PMID: 3747771

Henipavirus encephalitis

Abdullah S, Tan CT

Handb Clin Neurol, 2014;123:663-70.

PMID: 25015510 DOI: 10.1016/B978-0-444-53488-0.00032-8

Fulltext Ethical issues related to epilepsy care in the developing world

Tan CT, Avanzini G

Epilepsia, 2009 May;50(5):975-7.

PMID: 19170738 DOI: 10.1111/j.1528-1167.2008.01934.x

There are three major issues of ethical concern related to epilepsy care in the developing world. First, is it ethical for a developing country to channel its limited resources from direct epilepsy care to research? The main considerations in addressing this question are the particular research questions to be addressed and whether such research will bring direct benefits to the local community. Second, in a country with limited resources, when does ignoring the high treatment gap become an ethical issue? This question is of particular concern when the community has enough resources to afford treatment for its poor, yet is not providing such care because of gross wastage and misallocation of the national resources. Third, do countries with plentiful resources have an ethical responsibility to help relieve the high epilepsy treatment gap of poor countries? Indeed, we believe that reasonable health care is a basic human right, and that human rights transcend national boundaries. Although health care is usually the responsibility of the nation-state, many modern states in the developing world are arbitrary creations of colonization. There is often a long process from the establishment of a political-legal state to a mature functional nation. During the long process of nation building, help from neighboring countries is often required.

Fulltext Clinically definite multiple sclerosis in a young Malay female. A case report

Muthusamy E, Tan CT

Med J Malaysia, 1988 Jun;43(2):170-2.

PMID: 3237134

Fulltext A study of newly diagnosed epilepsy in Malaysia

Manonmani V, Tan CT

Singapore Med J, 1999 Jan;40(1):32-5.

PMID: 10361483

To determine the characteristics of newly diagnosed epilepsy in the multiracial population of Malaysia.

Fulltext Malaysian children with: "benign epilepsy of childhood with centrotemporal spikes"

Manonmani V, Tan CT

Singapore Med J, 1994 Jun;35(3):247-9.

PMID: 7997896

Benign epilepsy of childhood with centrotemporal spikes (BECT) was studied in Malaysian children, and was observed in Chinese, Malay and Indian children in the ratio 10:6:5. There were 12 boys and 9 girls. Fit frequency varied from almost daily to a single fit. The age of onset ranged from 2-13 years and BECT was not noted in any child over 13 years old. There was a strong circadian rhythm and fits occurred mainly in sleep. Generalised seizures were more common than partial seizures. During the 3-year study from April 1989 to April 1992, 21 children with BECT were identified from the EEG records done at the University Hospital and it was found that this genetic epilepsy which is autosomal dominant with age dependent penetrance occurs in approximately 4.8% of our epileptic children. In addition there were 3 children in whom petit mal co-existed with a BECT EEG trait.

Fulltext Juvenile myoclonic epilepsy--a report of 11 patients at the University Hospital, Kuala Lumpur

Manonmani V, Tan CT

Singapore Med J, 1993 Oct;34(5):378-80.

PMID: 8153678

This is a report on 11 cases of Juvenile Myoclonic Epilepsy (JME) from the University Hospital, Kuala Lumpur, all of whom were diagnosed in the last one and a half years. This genetic syndrome is seen in all the three main racial groups: Chinese, Malays and Indians. It accounts for 2% of the epilepsy patients seen at the neurology clinic. Lack of awareness is the main hindrance to diagnosis.
Study site: Neurology clinic, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia

Fulltext Evoked response study among Malaysian multiple sclerosis patients

Tan CT, Leong S

Singapore Med J, 1992 Dec;33(6):575-80.

PMID: 1488664

A study of visual evoked potential (VEP), brainstem evoked potential (BAEP) and median nerve somatosensory evoked potential (SSEP) in 26 Malaysian patients with clinically definite Multiple Sclerosis (MS). This study showed an overall high rate of abnormality, with 85% of patients for VEP, 31% for BAEP and 65% for median nerve SSEP. The rate of abnormality was particularly high for patients who were symptomatic, reaching 100% of patients for VEP, 50% of patients in BAEP, 83% of nerves for median nerve SSEP. The rate of abnormality among those who were asymptomatic was lower, varying from 32% of eyes in VEP, 27% of patients in BAEP and 31% of nerves in median nerve SSEP. Three out of 10 patients with optic spinal form of MS have abnormal BAEP. These show the usefulness of the evoked potential studies in confirming the clinical lesions as well as demonstrating subclinical involvement. The rate of abnormal evoked responses for the asymptomatic patients in this study is generally lower than that published elsewhere.

Clinical and pathological manifestations of human henipavirus infection

Wong KT, Tan CT

Curr. Top. Microbiol. Immunol., 2012;359:95-104.

PMID: 22427144 DOI: 10.1007/82_2012_205

The clinicopathological features of human Nipah virus and Hendra virus infections appear to be similar. The clinical manifestations may be mild, but if severe, includes acute encephalitic and pulmonary syndromes with a high mortality. The pathological features in human acute henipavirus infections comprise vasculopathy (vasculitis, endothelial multinucleated syncytia, thrombosis), microinfarcts and parenchymal cell infection in the central nervous system, lung, kidney and other major organs. Viral inclusions, antigens, nucleocapsids and RNA are readily demonstrated in blood vessel wall and numerous types of parenchymal cells. Relapsing henipavirus encephalitis is a rare complication reported in less than 10% of survivors of the acute infection and appears to be distinct from the acute encephalitic syndrome. Pathological evidence suggests viral recrudescence confined to the central nervous system as the cause.

Fulltext A review of multiple sclerosis with Asian perspective

Chong HT, Tan CT

Med J Malaysia, 2008 Dec;63(5):356-61.

PMID: 19803290 MyJurnal

Multiple sclerosis, although a rare disease in Asia, often presents significant diagnostic challenges to clinicians. There has been rapid advancement in the understanding of the underlying genetic influence, pathophysiology, investigation and treatment recently. This paper reviewed the latest development of various aspects of the disease and examined the differences between the manifestations of Asian and Western patients. The implications of these differences to investigation and treatment were also touched upon.

Nipah encephalitis outbreak in Malaysia

Tan CT, Wong KT

Ann Acad Med Singap, 2003 Jan;32(1):112-7.

PMID: 12625108

INTRODUCTION: Between September 1998 and June 1999, there was a severe outbreak of viral encephalitis among the pig farm workers in Malaysia.

METHODS: This is a review of the published literature related to the outbreak with the focus on human diseases.

RESULTS: The encephalitis was caused by a newly discovered paramyxovirus related to Hendra virus, later named Nipah virus. There were 265 patients with acute encephalitis. The disease is thought to spread from pig to man through close contact. The risk of human-to-human spread is thought to below. The disease affected mainly adult Chinese males, half of whom had affected family members. The disease presented mainly as acute encephalitis with a short incubation period of less than two weeks, with the main symptoms of fever, headache, and giddiness followed by coma. Distinctive clinical signs include segmental myoclonus, areflexia and hypotonia, hypertension, and tachycardia. Initial cerebrospinal fluid was abnormal in 75% of patients. Serology was helpful in confirming the diagnosis. Magnetic resonance imaging showed distinctive changes of multiple, discrete, and small high signal lesions, best seen with fluid-attenuated inversion recovery (FLAIR) sequences. Mortality was high at 40% and death was probably due to severe brainstem involvement. The main necropsy finding in acute encephalitis was that of disseminated microinfarction associated with vasculitis and direct neuronal involvement. Ribavirin was able to reduce the mortality by 36%. Relapse encephalitis was seen in 7.5% of those who recovered from acute encephalitis, and late-onset encephalitis in 3.4% of those with initial non-encephalitic or asymptomatic diseases. The mean interval between initial illness and the onset of the complication was 8.4 months. The relapse and late-onset encephalitis which manifested as focal encephalitis arose from recurrent infection.

CONCLUSION: Nipah virus, a recently discovered paramyxovirus, causes a unique encephalitis with high mortality as well as relapse and late-onset encephalitis. The infection is mainly spread from pigs to man.

Plasmapheresis in the University of Malaya Medical Centre, Malaysia

Chong HT, Tan CT

Ther Apher, 2001 Apr;5(2):147-9.

PMID: 11354300

Over the past 3 decades, plasmapheresis has been used more extensively for a variety of neurological and hematological disorders. We undertook a retrospective review to ascertain its safety, efficacy, and factor(s) that predispose to poor outcome. We reviewed 117 plasma exchanges in 24 patients with a mean age of 43 +/- 15 years; half were male. A total of 79% of the patients had neurological diseases, and the most common were chronic inflammatory demyelinating polyneuropathy, Guillain-Barré syndrome, and myasthenic crisis. Plasmapheresis was effective in 79% of the patients, especially for neurological indications. Complications occurred in 23% of the exchanges affecting 58% of the patients. Most complications were mild; sepsis was the most common (9.4% of exchanges), especially catheter related sepsis (6%), rash (4.3%), and hypotension (4.3%). Only 2 (8%) patients had severe complications that required mechanical ventilation. There were 5 mortalities (21%), 3 due to sepsis and 2 due to myocardial ischemia and arrhythmia, none of which occurred within 48 h of the last exchange. Patients with poor renal function had higher mortality. Overall, our figures agree with those from other institutions and indicate that plasma exchange is an effective and safe procedure, especially for a variety of neuroimmunological conditions.

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