Multiple sclerosis is an uncommon disease in Southeast Asia, having been characterised only recently. The estimated prevalence is about 2 – 3/105 , with high female to male ratio, but rare family history. As high as 40% of the patients had the optic-spinal phenotype; though patients in this region seldom progressed to the secondary progressive phase, disability was more severe due to severe spinal cord involvement. There is a great degree of overlap in clinical, radiological and laboratory features between the classical and the optic-spinal phenotypes, including long spinal cord involvement, few brain lesions, lower proportion of positive cerebrospinal fluid oligoclonal bands and anti-aquaporin-4 antibody. We proposed that future international diagnostic criteria need to take this into account.

Background and Objective: Nipah virus is an emerging zoonotic virus which caused fatal outbreak among Malaysian pig-farmers in 1998-1999. The Nipah virus outbreak represented one of the batderived paramyxoviruses that have emerged during the last decade to cause severe human and animal disease. Long-term neurological assessments and serological pattern descriptions are limited. We assessed persistent symptoms, neurological and functional outcome of 36 Nipah virus infection survivors after 10 years of the outbreak in Malaysia. Their serological pattern of Nipah virus for both IgM and IgG were studied. Methods: During September 2008 and March 2009, we administered a questionnaire on persistent symptoms and functional disability for all the Nipah virus infection survivors and Nipah infection contacts. Blood were collected for serological test for Nipah virus IgM and IgG. Results: A total of 70 subjects were included in the study, 39 of whom had virus Nipah infection in the past. Among the Nipah virus infection survivors, 31 (79%) were male; mean age was 46 + 1.8 years. Sixteen Nipah infection survivors (41%) were asymptomatic. The most common persistent clinical features were fatigue (12, 31%), daytime somnolence (10, 26%) and focal neurological deficits (8, 21%). Five out of 13 (38%) Nipah encephalitis survivors had significant disability on the modified Rankin scale. Serologically, all subjects were tested negative on the Nipah IgM serology test. IgG were positive for 39 subjects in which 3 had asymptomatic infection during the outbreak. Conclusion: Persistent fatigue and daytime somnolence were common disabling symptoms after 10 years of Nipah virus infection, seen in those with previous encephalitis as well as non-encephalitic infection. Serologically all patients had negative Nipah IgM but positive IgG after 10 years of illness.

Neuromyelitis optica (NMO) was first described as a severe monophasic syndrome of acute bilateral optic neuritis and transverse myelitis. Whether it is a form of multiple sclerosis (MS) or a separate disease entity has been continually debated since the beginning of last century. The redefinition of NMO as a relapsing disease, the wider use of magnetic resonance imaging showing longer spinal cord lesion, and the recently discovered anti-aquaporin-4 (AQP4) water channel antibody, or NMO-IgG, has rekindled this controversy. The many recent publications including the abstracts published in this issue of Neurology Asia have shown that anti-AQP4 antibody is of variable sensitivity in different populations. It appears to be associated mainly with longitudinal extensive spinal cord lesions and frequent relapses. The site of pathology of NMO also do not co-localize with the widespread expression of AQP4 in the body, throwing doubts on the suggestion that the anti-AQP4 antibody plays primary role in the pathogenesis of NMO. In the day-to-day clinical practice in Asia, anti-AQP4 antibody remains a research investigatory test. As for optic-spinal MS, which is closely similar to NMO based on recently revised criteria, interferon should remain the treatment of first choice.

Measles virus causes three distinct neurological syndromes: acute disseminated encephalomyelitis, subacute sclerosing panencephalitis and the rare subacute measles encephalitis, or inclusion body measles encephalitis. There is a current debate of whether subacute measles encephalitis is an opportunistic infection or a subacute infection caused by a mutated measles strain. There is also no report of long term MRI of survivor. We reported a young Chinese girl with a history of relapsed acute lymphoblastic leukaemia and subacute measles encephalitis confirmed by brain biopsy who survived. Serial magnetic resonance imaging of the brain showed cortical and basal ganglial involvement in the initial phase, and generalized cerebral atrophy in the subsequent scan four and a half years later. The patient recovered from subacute measles encephalitis with substantial neurological deficits with the cessation of maintenance chemotherapy without specific antiviral treatment. This suggested that reconstitution of host immunity was adequate in effecting the clearance of the virus, and supporting the hypothesis that subacute measles encephalitis is primarily an opportunistic infection.

Background and Objective: Comparable data are sparse for infl ammatory demyelinating diseases of the central nervous system (CNS) in the Asia-Pacifi c region, and we aimed to establish a registry of patients with such diseases in the region. Methods: A network of neurologists in the Asia-Pacifi c Region was established to register patients with the targeted diseases. A standardized register form and relevant instructions in English, translated into the local language when needed, were prepared before the study start and used for data collection. Results: Eight study centres from different countries/areas participated in the study. In total, 857 patients with a validated diagnosis of different infl ammatory demyelinating diseases of the CNS were registered, 591 females and 266 males with a female-to-male ratio 2.2. The mean age at onset for all patients was 35.9 (SD: 12.9) years, signifi cantly younger (p = 0.010) for females (35.1 years, SD: 12.6 years) than for males (37.6 years, SD: 13.4 years). Conclusion: Patients with different infl ammatory demyelinating diseases of the CNS were in the fi rst time registered in a multi-centre study from eight countries/areas in the Asia-Pacifi c region. A platform and basis has been established for further study in the fi eld.