Verbal memory deterioration after unilateral infarct of the internal capsule in an adolescent.

After an infarction in the territory of the anterior perforating arteries, a 15-year-old, previously healthy, left-handed patient developed considerable verbal long term memory disturbances which could be followed up and tested for more than nine months. An extensive memory test battery was used to determine spared and impaired functions. The patient had remote memory disturbances with respect to personal events for the last 5 years and problems in all verbal task tested which required remembering items over time periods exceeding an hour. The patient was indistinguishable from control subjects on short-term memory tests and on a number of nonverbal learning and recognition tests. The crucial lesion for the observed deficits in the genu of the left internal capsule was assumed to have disrupted the anterior and inferior thalamic peduncles, fornix (column), stria terminalis, anterior commissure and the medial part of the globus pallidus. This infarct, therefore, most likely damaged traversing fibres which intercommunicate within the Papez circuit and the basolateral limbic circuit and which in part provide access to cortical memory representing areas.