Abstract
The purpose of this paper is to call to the attention of neurologists, psychiatrists and neurosurgeons a group of meningiomas with dementia as the earliest and presenting symptom. The diagnosis in these cases is apt to be missed, especially if the patient is in the arteriosclerotic or presenile age-group. This is equally true of other tumours, but the practical importance of early diagnosis of meningiomas is that with the removal of the tumour the patient usually recovers from the mental illness.