Brain and spinal cord magnetic resonance imaging in Thai multiple sclerosis patients

Objective: To evaluate magnetic resonance imaging (MRI) of multiple sclerosis (MS) patients in Thailand. Method: A retrospective review on the initial brain and spinal cord MRI in MS patients was done but primary progressive MS and the AQP4 antibody positive patients were excluded. The characteristics of brain and spinal cord MRI were analyzed. Results: For the initial brain MRI studies, fi fty percents satisfi ed McDonald MRI criteria for dissemination in space. For the initial spinal cord MRI, most lesions involved thoracic level and the mean length of spinal cord lesion is 1.29 vertebral body segments (range 0-3). Conclusion: For Brain MRIs in Thai MS patients, there was 50% in sensitivity by the 2005 McDonald’s Criteria for dissemination in space, which is similar to the previous Asian reports. For spinal MRI, the median length of lesions was less than previous Asian reports. This could be due to the fact that AQP4 antibody positive patients, in whom the clinical and imaging features are hard to differentiate from MS patients, were excluded. In other word, the neuromyelitis optica (NMO) spectrum disorders had been more effectively excluded in this study than those in the past. This supports the importance of NMO IgG/AQP4 antibody testing in differentiating MS from NMO spectrum disorders, especially in Asian patients. Neurology Asia 2012; 17(1) : 55 – 61 Address correspondence to: Pornpong Jitpratoom MD, Chumphonkatudomsak Hospital, Pisitpayabarn Road, Mueang district, Chumporn Province, Thailand, 85000. Phone: (077)501716. E-mail:[email protected] INTRODUCTION Multiple sclerosis (MS) is considered an uncommon disease in Asian and has been reported to show several different features from the western countries, which were lower prevalence, rare positive family history, higher prevalence in female, frequent occurrence of acute transverse myelitis, higher frequency of paroxysmal tonic spasm, less frequent involvement of cerebellum, higher prevalence of opticospinal form, lower incidence of positive oligoclonal bands in cerebrospinal fl uid, and longer spinal cord lesions on magnetic resonance imaging (MRI). In 2001, the International Panel on the diagnosis of MS proposed a guideline for the diagnosis of MS, which was revised in 2005. In both criteria, MRI is a very important tool to determine dissemination in space (DIS) and time (DIT) for the diagnosis of MS. Studies on MRI fi ndings in MS in Asian as well as Thai populations revealed low sensitivity of McDonald MRI criteria for dissemination in space. According to the revised diagnostic criteria of neuromyelitis optica (NMO), the NMO antibody testing in very important. In Asia, the NMO IgG antibody detection was not available in the past. For that reason, some NMO spectrum disorder patients were diagnosed to have MS. That is very important because, although MS and NMO are both neuroinfl ammatory diseases, the fi rst line treatment is different. For NMO, immunosuppressive drug is the fi rst but for MS, the fi rst line drug is Interferon beta. Therefore, we undertook this study to better delineate the MRI characteristics of Thai MS patients from whom we have excluded NMO spectrum disorder patients. This study was conducted to evaluate magnetic resonance imaging (MRI) in multiple sclerosis (MS) patients in Siriraj Hospital MS clinic which is the large referral center of Thailand and excluded the NMO spectrum disorder by using NMO IgG antibody test. Neurology Asia March 2012