前島 伸一郎

Background: Cognitive disorders, such as memory disturbances, are often observed following a subarachnoid hemorrhage. We present a very rare case where rupture of a posterior cerebral artery aneurysm caused restricted damage to the hippocampus unilaterally, and caused memory disturbances. Case presentation: A 56-year-old, right-handed man, with a formal education history of 16 years and company employees was admitted to our hospital because of a consciousness disturbance. He was diagnosed as having a subarachnoid hemorrhage due to a left posterior cerebral artery dissecting aneurysm, and coil embolization was performed. Subsequently, he had neither motor paresis nor sensory disturbances, but he showed disorientation, and both retrograde and anterograde amnesia. Although immediate recall and remote memory were almost intact, his recent memory was moderately impaired. Both verbal and non-verbal memories were impaired. Brain computed tomography (CT) and magnetic resonance imaging (MRI) revealed a cerebral hematoma in the left temporal lobe involving the hippocampus and parahippocampal gyrus, and single-photon emission computed tomography (SPECT) demonstrated low perfusion areas in the left medial temporal lobe. Conclusions: We suggest that the memory impairment was caused by local tissue destruction of Papez's circuit in the dominant hemisphere due to the cerebral hematoma.

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.

Causative factors for pneumonia and their impact on prognosis were investigated in patients with acute ischemic stroke. Patient characteristics, swallowing function, lesions, and the presence or absence of intervention by dysphagia rehabilitation were assessed in 292 patients with acute cerebral infarction to determine the association of these factors with pneumonia. As a result, 52 patients (17.8%) experienced pneumonia. Of these, 14 developed pneumonia within 3 days of hospital admission and 38 developed the disease after 4 days or later. Pneumonia was frequently seen among elderly patients, those with severe neurological symptoms or cognitive disorders and those with bilateral multiple lesions, and was associated with prolonged length of stay and decline in activities of daily living at hospital discharge. In conclusion, elderly age, bilateral lesions, and severe neurological deficit were significantly associated with pneumonia. Pneumonia in turn strongly predicted inability to take food orally and be discharged from hospital to home.