Cortical vs Subcortical Dementia: Neuropsychological Similarities-Reply

In Reply.  —Since its inception, the hypothesis of cortical/subcortical dementia has been controversial, and obviously still generates healthy disagreement. The subcortical dementia syndrome includes depression, forget-fulness, apathy, and impairment of cognitive and visuospatial skills. Unlike patients with cortical dementia, there is no abnormality of language function, agnosia, or apraxia, and the dementia is characteristically less severe. At present, despite the suggestive terminology, the distinction between cortical and subcortical dementias is mainly a clinical one; pathologic correlation is little more than speculative, and was not addressed in our report.Despite numerous reviews, only two experimental studies^1,2 have objectively evaluated the concept. Our findings suggested a qualitative difference and supported Benson's statement³ that "It is obvious that the clinical features alone provide a clear distinction between the two types of dementia." We found dementia in Parkinson's disease (PD) to be less severe than that in dementia of the Alzheimer type