Clinical features and SPECT scanning in presumed cortico-basal ganglionic degeneration.

Eight patients presented with a strikingly similar core syndrome of asymmetric upper limb rigidity and dystonia (which was maximal in the non-dominant limb in seven), accompanied by ipsilateral ideomotor apraxia, cortical sensory disturbane, and sensory reflex myoclonus. The clinical diagnosis in each case was of presumed cortico-basal ganglionic degeneratioan. The clinical features in our cases matched those of other series closely, except for a higher prevalence of dementia (presumably explained by referral bias), and a lower incidence of oculomotor abnormalities. Seven of the eight patients underwent (59)Tc-HMPAO SPECT scanning, which in each case revealed contralateral fronto-parietal perfusion defects out of proportion to the focal or generalised atrophy demonstrated on MRI scans. SPECT scanning appears to be a useful confirmatory investigation in patients presenting with this uncommon but distinctive clinical syndrome, and in separating them from patients with other causes of asymmetric rigid syndromes, such as Parkinsons's disease.