Cortical Lewy body dementia: clinical features and classification.

Seven patients, aged 65-72 years, are described with dementia and cortical Lewy bodies. In one patient a Parkinsonian syndrome was followed by dementia and motor neuron disease. In the remaining six patients dementia was accompanied by dysphasia, dyspraxia and agnosia. One developed a Parkinsonian syndrome before the dementia, in three cases a Parkinsonian syndrome occurred later, and in two cases not at all. All patients showed Lewy bodies and cell loss in the substantia nigra, locus coeruleus and dorsal vagal nucleus, as in Parkinson's disease. The severity of cell loss in the nucleus basalis varied from mild to severe. Lewy bodies were also present in the parahippocampus and cerebral cortex, but Alzheimer-type pathology was mild or absent, and insufficient for a diagnosis of Alzheimer's disease. Patients with moderate or severe dementia, some with temporal or parietal features, may have cortical Lewy body disease, Alzheimer's disease, or a combination of the two. Cortical Lewy body disease may be associated with dementia in Parkinson's disease more often than realised, but is not necessarily associated with extensive Alzheimer pathology.