Unilateral spatial neglect in the late stage of Alzheimer's disease.

We report two patients with presumptive diagnosis of dementia of the Alzheimer's type (AD) who manifested a clear unilateral neglect syndrome in the late stage of the disease. At onset, their cognitive profiles were broadly similar to the usual cases of degenerative dementia, but, as the disease progressed, neglect appeared, becoming gradually more severe. MRI showed more pronounced cerebral atrophy in the right hemisphere in both patients and larger ventricles on the right in one of them. These two longitudinal single case studies show that neglect can occur in AD despite the insidious and progressive nature of this disease, and in spite of the fact that the underlying pathology affects the brain bilaterally. The appearance of neglect in the late stages of the patients' illness is interpreted as resulting from both the asymmetry in the atrophy and the disruption of compensatory mechanisms caused by the progressively worsening of the atrophy in the left hemisphere.