[Presenile dementia with marked recent memory disturbance--in relation to hippocampal dementia].

Two cases of presenile dementia with marked recent memory disturbance were reported. Patient 1 is a 54-year-old woman. She noticed forgetfulness at the age of 51 years. Neurological examination at aged 52 revealed marked recent memory disturbance, but examination by WAIS (Wechsler Adult Intelligence Scale) showed good results (verbal IQ 106, performance IQ 104, total IQ 106). There was neither disorientation in place nor character change. Cranial CT scan and MRI revealed the absence of brain atrophy. About 3 years after the onset of the disease, the degree of dementia is slight and disorientation in place does not appear. Patient 2 is a 67-year-old man. He noticed forgetfulness at the age of 63 years. Neurological examination at aged 66 revealed marked recent memory disturbance, but examination by WAIS-R showed moderate results (verbal IQ 89, performance IQ 87, total IQ 88). There was neither disorientation in place nor character change. Cranial CT scan and MRI revealed slight dilatation of the inferior horns of the lateral ventricle and slight cortical atrophy. About 4 years after the onset of the disease, the degree of dementia was slight and disorientation in place did not appear. We can not rule out the possibility that our cases belong to Alzheimer's disease, but the clinical course of our cases is peculiar. In the relation of responsible lesion in pure amnestic syndrome, hippocampal dementia, and simple senile dementia, our cases are interesting and important.