Organic mental syndrome and confusional states in Parkinson's disease. Relationship to computerized tomographic signs of cerebral atrophy.

Ninety-three patients with a diagnosis of Parkinson's disease, otherwise unselected, were specifically evaluated for organic mental syndrome (OMS) and other neurologic motor signs other than those referrable to extrapyramidal dysfunction; in addition, they had cranial computerized tomography (CT) to measure any structural changes in brain parenchyma. Cortical (sulci) atrophy and ventricular enlargement as CT signs of cerebral atrophy were correlated with different clinical patterns of the disease. An age-adjusted control population, with intact mentation, was similarly studied. The presence of classic OMS in a sizable segment of the usual parkinsonian population was invariably associated with CT signs of cerebral atrophy. Atrophic changes on CT scans, however, were not necessarily correlated with any intellectual dysfunction, or only weakly so, independent of age. The "typical" parkinsonian patients without evidence of OMS were indistinguishable from an age-adjusted control group with regard to structural changes in their scans. However, the parkinsonian patients with definite, permanent OMS and other focal neurologic deficit probably constitute a separate or distinct subset of the parkinsonian population, with a pathologic substrate more likely to be similar to that of the so-called Alzheimer-type dementias. Duration of the parkinsonian syndrome was not predictive of either mental status or scan findings, after adjustment for age as a factor.