Pure akinesia with low myocardial metaiodobenzylguanidine uptake.

The objective of this study was to delineate the clinical features of patients with pure akinesia and a low heart versus mediastinum ratio below 2.0 in the delayed images of myocardial metaiodobenzylguanidine scintigraphy, a marker for the clinical diagnosis of Lewy body diseases. A total of 13 patients was enrolled. The clinical features of the patients were uniformly elderly (mean age, 73.7 years), a male gender preponderance (10 men and 3 women), relatively mild motor disability (mean Hoehn Yahr grade 2.4) without laterality, festinating gait (77%) and loss of postural reflex (69%), which were the most common; also observed were fair levodopa responses (70%), cognitive dysfunction in some (23%), common autonomic dysfunction (urinary urgency and frequency, 85%; constipation, 77%; and postural hypotension, 38%) and common occipital hypoperfusion (62%). These features may facilitate the clinical differential diagnosis of these patients from patients with pure akinesia due to progressive supranuclear palsy.