The prevalence of neglect: superiority of neuropsychological over clinical methods of estimation.

As anatomical studies have suggested that neglect might occur more frequently than is presently realized, and since pilot studies with dopamine agonists have suggested a possible therapy, we examined whether simple neuropsychological tests could detect neglect in the presence of a negative clinical examination. We found evidence of neglect on a simple arrow and number cancellation test in patients with lesions in either hemisphere and Parkinsonians. Clinical examination failed to identify neglect in all but three patients of the right hemisphere group. Cancellation tests are able to detect subclinical neglect, which could be important in view of possible future therapy.