Nationwide survey of Alexander disease in Japan and proposed new guidelines for diagnosis.

[alexander disease]

Alexander disease (AxD ) is a rare neurodegenerative disorder characterized by white matter degeneration and formation of cytoplasmic inclusions . Glial fibrillary acidic protein (GFAP ) mutations have been reported in various forms of AxD since 2001 . However , a definitive diagnosis remains difficult because of uncertain prevalence , and different clinical features seen in infantile AxD and adult AxD may lead to confusion and misdiagnosis . Here we report an epidemiological study conducted in Japan . Two nationwide questionnaire-based surveys were conducted using tentative diagnostic criteria . We gathered information regarding prevalence , neurological findings , magnetic resonance imaging (MRI ) findings , electrophysiological findings , genetic information , and the results of therapeutic interventions and home care . Prevalence of various forms of AxD was determined as 27 .3 % (infantile ), 24 .2 % (juvenile ), and 48 .5 % (adult ). Prevalence of AxD in Japan was estimated to be approximately 1 case per 2 .7 million individuals . The main characteristics of infantile and juvenile AxD include delayed psychomotor development or mental retardation , convulsions , macrocephaly , and predominant cerebral white matter abnormalities in the frontal lobe on brain MRI . The main characteristics of adult AxD include bulbar signs , muscle weakness with hyperreflexia , and signal abnormalities and /or atrophy of medulla oblongata and cervical spinal cord on MRI . To ensure correct diagnosis of AxD , the physician should understand the importance of the process of GFAP genetic testing , which provides definitive diagnosis . Therefore , we propose new clinical guidelines for diagnosing AxD based on simplified classifications : cerebral AxD (type 1 ), bulbospinal AxD (type 2 ), and intermediate form (type 3 ).

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alexander disease

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