[Amnesia, confabulation and nonaphasic misnaming after left thalamic infarct].

A 72-year-old right handed woman developed amnesia, confabulation and abnormal (bizarre) verbal response after the left thalamic infarction. Clinical features including disorientation, euphoria and various kinds of paraphasia coincided in nonaphasic misnaming. MR images showed that lesions involved the genu of the internal capsule, the anteroventral nucleus, the lateroventral nucleus, intralaminar nuclei, the mamillothalamic tract and the region around the ventral thalamus. 99mTc-HMPAO-SPECT revealed decreased uptake in the left frontal lobe, probably due to the disconnection from the thalamus. These findings suggest that the dysfunction of the thalamus (mainly ventrolateral) and the left frontal lobe caused the disturbance of the self-monitoring in the language use, which generated confabulation and nonaphasic misnaming in our case.