We recently cared for a patient with hypertension who presented with severe amnesia. Magnetic resonance imaging of the brain revealed localized intracerebral hemorrhage in the left medial temporal lobe. There have been only a few case reports of severe amnesia caused by a restricted hemorrhagic lesion in the unilateral medial temporal lobe (Arai et al., Reference Arai, Sakurai, Shikai, Fuse and Shimpo2006). Here, we present an elderly woman who developed severe amnesia due to left hippocampal hemorrhage. The authors obtained informed consent to the publication of this letter from the patient's son, who was her legal guardian.
A 71-year-old right-handed Asian woman with a 20-year history of hypertension came to the hospital with her family because she could not remember what she had said and heard just a few minutes before. Her blood pressure was 190 mmHg systolic and 120 mmHg diastolic. She had no abnormal neurological findings and laboratory evaluations were within normal range. Her score on the revised version of Hasegawa's dementia scale (a Japanese screening test for dementia, almost identical to the Mini-mental State Examination, with a score range 0–30; Katoh et al., Reference Katoh1991) was 15 points. Neuropsychological tests showed recent memory impairment and disorientation with regard to time, although she retained immediate and remote memory. T1-weighted magnetic resonance imaging of the brain revealed enlargement of the lateral ventricles and abnormal hyperintensity of a localized region adjacent to the hippocampus in the left medial temporal lobe (see Figure S1 available as supplementary material attached to the electronic version of this letter at www.journals.cambridge.org/jid_IPG). She was admitted with hypertensive intracerebral hemorrhage and treated for the management of her blood pressure. One month later, she was discharged from hospital and went home, but her recent memory impairment and temporal disorientation did not ameliorate, and anterograde amnesia persisted.
Amnesia has been known to be caused by several medical conditions and etiologies such as traumatic head injury, cerebrovascular disease, brain tumor, encephalitis, vitamin deficiency, alcoholism, hypoxic/anoxic encephalopathy, and degenerative disease (Wood, Reference Wood1984; Kopelman, Reference Kopelman2002). However, the case reported here suggests that clinicians should consider that severe amnesia can occur on rare occasions due to a restricted lesion in the unilateral medial temporal lobe.
