Transient Automatic Writing Behavior following a Left Inferior Capsular Genu Infarction.

A 79-year-old, right-handed woman was admitted to the hospital with decreased spontaneity. Brain magnetic resonance imaging showed a left inferior capsular genu infarction. (99m) TC-ECD single-photon emission computed tomography revealed a left-dominant diffuse hypoperfusionin the basal ganglia and frontal lobe. The patient showed abulia and increased writing activity without motor or sensory deficit. The writing was mainly perseverative, and words written along lines were legible and without spatial distortions. This augmented writing behavior disappeared on day 21. The writing characteristic was more similar to automatic writing behavior than hypergraphia. Dissociation between speech and writing behavior was present in our patient. We suggest that a disconnection within the frontal-subcortical circuit contributed to the development of motor perseveration in writing.