[A case of Alexander disease presented with dystonia of lower limb and decreased dopaminergic uptake in dopamine transporter scintigraphy].

A 50-year-old woman developed gait disturbances and dysarthria since the past 2 years. She also presented with dystonia and hypokinesia of her left lower limb, and orthostatic hypotension. The dopamine transporter SPECT with I ioflupane showed abnormal scans in bilateral striatum. Cerebral MRI revealed atrophy and signal changes in the medulla and spinal cord, from which Alexander disease (AxD) was suspected. Consequently, we checked the Glial fibrillary acidic protein (GFAP) gene. The analysis of the gene detected a heterozygous c.219G>T mutation, which was the first mutation reported in Japan, and finally she was diagnosed with AxD. Dystonia is relatively rare in AxD patients, but this case demonstrated that AxD should be listed in the differential diagnosis of extrapyramidal syndromes with abnormalities of the medulla and spinal cord on MRI.