Echo Induction Test for Hyperlexia and Ambient Echolalia in a Case with Cerebral Infarction / The Japanese Journal of Rehabilitation Medicine

ABSTRACT

Hyperlexia and ambient echolalia are rare conditions, and investigations into their clinical course have not been reported in the literature thus far. Here we report the case of a 69-year-old woman with cerebral infarction of the left anterior cingulate cortex and corpus callosum, on whom we performed an echo induction test for studying her long-term hyperlexia and ambient echolalia. Her clinical features included symptoms of complex disorders such as visual groping, compulsive manipulation of tools and callosal disconnection syndrome. The patient did not have dementia or aphasia. Her most outstanding behavioral traits were the hyperlexia and ambient echolalia. We investigated the induction of her hyperlexia and ambient echolalia by subjecting the patient to 10 verbal questions using a background of visual (bookshelves were placed in front of her) and auditory (imitated hospital announcements) stimuli at periods of 1, 2 and 6 months after the stroke. Hyperlexia was induced at 1 and 2 months after stroke, whereas ambient echolalia was only induced at 1 month after stroke. The disappearance of the hyperlexia and ambient echolalia in this case might be due to a reduction in the disinhibition of response to external stimuli caused by damage sustained in the stroke to the left anterior cingulate cortex and corpus callosum.