Diencephalic temporal order amnesia.

OBJECTIVE: Amnesia for temporal relations may occur without amnesia for content memories. The aim was to determine whether a patient with mild memory loss due to a thalamic lesion had amnesia for temporal relations, and whether the amnesia was specific for particular material.
METHODS: A male patient had an isolated right dorsomedial thalamic infarct and resolving amnesia. He was tested on tasks relating to content (what) and temporal (when) memories for both verbal and non-verbal material, three and seven months after his infarct.
RESULTS: Three months after his infarct, the man had amnesia for temporal, but not content memories using non-verbal stimuli, and normal performance using verbal stimuli. Seven months after his infarct, he had a normal performance using verbal and non-verbal stimuli.
CONCLUSIONS: Patients with thalamic lesions may have a material specific amnesia for temporal relations in the absence of amnesia for content.