Diffuse Lewy body disease presenting as multiple system atrophy

The majority of patients with diffuse Lewy body disease have cognitive or psychiatric manifestations as part of their initial presentation. A sizable minority present with parkinsonian features alone. Autonomic features may also occur, typically after the development of cognitive changes. We aim to demonstrate that diffuse Lewy body disease may rarely also present with parkinsonism accompanied by marked autonomic dysfunction in the absence of significant cognitive or psychiatric abnormalities.

Case report based on a retrospective chart review and neuropathological examination.

We report on a patient in whom a clinical diagnosis of multiple system atrophy was made based on a presentation of parkinsonism with prominent and early autonomic involvement. The former included postural tremor, rigidity and bradykinesia, while the latter consisted of repeated falls due to orthostasis and the subsequent development of urinary incontinence midway through the course of her illness. She was poorly tolerant of dopaminergic therapy due to accentuated orthostasis. Benefit from levodopa was limited and only evident when attempted withdrawal resulted in increased rigidity. There was no history of spontaneous or drug-induced hallucinations, delusions or fluctuating cognition, and in contrast to the prominence and progression of her parkinsonian and autonomic features over the first several years, cognitive impairment did not occur until the final stages of her illness, seven years after the onset of initial symptoms. Neuropathological examination revealed numerous Lewy bodies in both neocortical as well as subcortical structures consistent with a diagnosis of diffuse Lewy body disease. There was marked neuronal loss in the substantia nigra as well as the autonomic nuclei of the brainstem and spinal cord.

In addition to cognitive, psychiatric, and parkinsonian presentations, diffuse Lewy body disease may present with parkinsonism and prominent autonomic dysfunction, fulfilling proposed criteria for the striatonigral form of MSA.