Forced hyperphasia and environmental dependency syndrome.

A distinctive, language related fragment of the environmental dependency syndrome is described: compulsive, involuntary, environmentally dependent speaking. Because this syndrome represents the observe of aphasia, it is named forced hyperphasia. An 84 year old woman with acute left frontal infarction was admitted to hospital with gait disturbance, forced grasp reflex, and striking imitation behaviour. After 2 weeks her imitation behaviour disappeared, but an equally striking new behaviour emerged. In the presence of others she would call out the names of objects in the room, and also call out the actions and gestures of people in the room, even though she was not asked to do so, and even though she was asked to stop. For example, if the doctor scratched his nose, she said, "The doctor is scratching his nose." Brain CT, MRI, and SPECT showed cerebral atrophy and a left superior frontal subcortical infarct. It is suggested that "forced hyperphasia" is a clinical fragment of the environmental dependency syndrome and that her compulsive, impulsive, involuntary release of spoken language resulted from the release of frontal inhibition of the complex reflex linking environmental cues to the set of motor, limbic, spatial, and linguistic associations underlying spoken language.