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Memory loss due to transient hypoperfusion in the medial temporal lobes including hippocampus
Author(s) -
Tanabe H.,
Hashikawa K.,
Nakagawa Y.,
Ikeda M.,
Yamamoto H.,
Harada K.,
Tsumoto T.,
Nishimura T.,
Shiraishi J.,
Kimura K.
Publication year - 1991
Publication title -
acta neurologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.967
H-Index - 95
eISSN - 1600-0404
pISSN - 0001-6314
DOI - 10.1111/j.1600-0404.1991.tb04897.x
Subject(s) - transient global amnesia , hippocampus , amnesia , cerebral blood flow , magnetic resonance imaging , lesion , temporal lobe , medicine , perfusion , memory disorder , neuroscience , psychology , anesthesia , radiology , pathology , cognitive disorder , epilepsy , cognitive impairment , psychiatry , cognition
A typical case of transient global amnesia (TGA) was investigated with single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) with 1.5‐tesler scans. During the amnesic eposide, a marked decrease of cerebral blood flow was observed in the areas confined to the territory of the bilateral posterior cerebral arteries including the hippocampus. After the episode, cerebral blood flow returned to normal and a circumscribed lesion was detected in the middle portion of CA 1 field of the left hippocampus. The SPECT findings prove direct evidence that the medial temporal structures are involved in the establishment of new memories, as well as in process of recalling only recently acquired memories, but not in retrieval of memories acquired long ago. The MRI findings indicate that a unilateral partial damage to CA 1 sector of the hippocampus does not develop a definite memory impairment and that high‐resolution MRI study on the hippocampus is necessary in TGA patients.