title: Retrosplenial amnesia without topographic disorientation caused by a lesion in the nondominant hemisphere.
abstract: We report the case of a 68-year-old right-handed man who was admitted to our hospital because of sudden onset of headache. On admission, he presented with left homonymous hemianopsia, disorientation, and recent memory disturbance; however, he had normal remote memory and digit span. He was able to recall the room layout of his house and describe the route from the nearest station to his home on a map. However, at the hospital, he sometimes lost his way because of amnesia. Computed tomography (CT) and magnetic resonance imaging revealed a subcortical hematoma in the right occipital forceps and the parietal lobe, involving the cingulate isthmus. Single-photon emission CT imaging showed reduced perfusion not only in the retrosplenial region but also in the right thalamus. These findings suggested that the retrosplenial amnesia might have been caused by the interruption of hippocampal input into the anterior thalamus.
authors.affiliation: Department of Rehabilitation Medicine, Saitama Medical University International Medical Center, Hidaka, Saitama, Japan. Electronic address: maeshima@fujita-hu.ac.jp.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Maeshima
authors.affiliation: Department of Rehabilitation Medicine, Saitama Medical University International Medical Center, Hidaka, Saitama, Japan.
authors.forename: Aiko
authors.initials: A
authors.lastname: Osawa
authors.affiliation: Department of Endovascular Neurosurgery, Saitama Medical University International Medical Center, Hidaka, Saitama, Japan.
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Yamane
authors.affiliation: Department of Endovascular Neurosurgery, Saitama Medical University International Medical Center, Hidaka, Saitama, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yoshihara
authors.affiliation: Department of Endovascular Neurosurgery, Saitama Medical University International Medical Center, Hidaka, Saitama, Japan.
authors.forename: Ryuzaburo
authors.initials: R
authors.lastname: Kanazawa
authors.affiliation: Department of Endovascular Neurosurgery, Saitama Medical University International Medical Center, Hidaka, Saitama, Japan.
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Ishihara
mesh_terms: D000368:Aged; D020324:Amnesia, Anterograde / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D002543:Cerebral Hemorrhage / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D002560:Cerebrovascular Circulation; D003221:Confusion / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D007839:Functional Laterality; D006406:Hematoma / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory; D009483:Neuropsychological Tests; D055420:Perfusion Imaging / Q000379:methods; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
keywords: Memory impairment; amnesia; cerebral hemorrhage; retrosplenial region; thalamus