A case of progressive ataxia followed by cognitive and behavioral changes.

The patient is a 60-year-old man who initially presented to his local hospital with complaints of gait difficulties that started suddenly after waking. Results of brain magnetic resonance imaging performed 1 week later were normal. Three weeks after that he developed blurred vision and he complained of a severe headache in the posterior head and neck regions at the onset of symptoms, which necessitated several visits to his local emergency room. The patient presented to our institution 1 month later, with progressive gait difficulty and truncal instability over a 2-week period.