[A case of Alexander disease with dropped head syndrome].

A 51-year-old woman presented with progressive weakness of the neck extensor muscles and gait disturbances since the past 6 years. In addition, she presented with symptoms such as dysarthria, dysphagia, bladder, and rectal disturbances. Bilateral plantar reflex was positive. Her gait was short-stepped-spastic. Brain and cervical MRI showed atrophy of the medulla and spinal cord. As these imaging features were suggestive of Alexander disease (AxD), we sequenced the GFAP gene. We identified a heterozygous c.368T>C missense mutation of the GFAP gene in the patient. This was the first case of the mutation in Japanese patients, and subsequently, she was diagnosed with AxD type 2. There are a few studies which reported that patients with AxD complained of dropped head syndrome. Dropped head syndrome can be the initial manifestation of AxD.