title: Reversible hippocampal lesions detected on magnetic resonance imaging in two cases of transient selective amnesia for simple machine operation.
abstract: We report two extremely rare cases involving the development of transient selective retrograde amnesia for simple machine operation lasting for several hours. A 61-year-old male taxi driver suddenly became unable to operate a taximeter, and a 66-year-old female janitor suddenly became unable to use a fax machine. They could precisely recount their episodes to others both during and after the attacks, and their memories during their attacks corresponded to the memory of the witness and the medical records of the doctor, respectively. Therefore, it appears that these individuals remained alert and did not develop anterograde amnesia during their attacks. On day 4, they underwent high-resolution magnetic resonance imaging (MRI), and diffusion-weighted MRI with 2-mm section thickness revealed small high-intensity signal lesions in the left hippocampal cornu ammonis area 1 (CA1) region. However, these lesions disappeared during the chronic phase. This is the first report describing lesions detected by MRI in patients with transient selective amnesia without anterograde amnesia. Reversible damage to the hippocampal CA1 region may cause transient selective amnesia by impairing the retrieval of relevant memories.
authors.affiliation: a Stroke Center, NTT Medical Center Tokyo , Tokyo , Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Yamaoka
authors.affiliation: b Department of Neurology , Tokyo Metropolitan Neurological Hospital , Tokyo , Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Bandoh
authors.affiliation: a Stroke Center, NTT Medical Center Tokyo , Tokyo , Japan.|c Department of Neurosurgery , NTT Medical Center Tokyo , Tokyo , Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kawai
mesh_terms: D000368:Aged; D000648:Amnesia, Retrograde / Q000000981:diagnostic imaging / Q000503:physiopathology*; D020236:Amnesia, Transient Global / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged
keywords: Transient selective amnesia; high-resolution MRI; hippocampus; machine operation; transient procedural amnesia