CEREBRAL BLOOD-FLOW IN SPINOCEREBELLAR DEGENERATIONS - A SINGLE-PHOTON EMISSION TOMOGRAPHY STUDY IN 28 PATIENTS

We used single photon emission tomography to study regional cerebral p erfusion in patients with different forms of spinocerebellar degenerat ion: 6 patients with Friedreich's ataxia (FA), 6 with early-onset cere bellar ataxia with retained tendon reflexes (EOCA), 5 with autosomal d ominant cerebellar ataxia type 1 (ADCA I) and 11 with idiopathic late- onset cerebellar ataxia (ILOCA). The results were related to clinical and magnetic resonance imaging (MRI) findings. Cerebellar hypoperfusio n was constant in ADCA I and frequent in patients with other spinocere bellar degenerations. Brain stem hypoperfusion was constant in ADCA I, frequent in ILOCA patients with pontocerebellar atrophy and absent in FA and EOCA. FA and EOCA often showed a reduction in the parietotempo ral cortex blood flow, which was not related to cortical atrophy. ILOC A patients had an asymmetric pattern in the temporal areas with decrea sed blood flow in the right side only. Caudate hypoperfusion was found in ADCA I patients. Cerebral atrophy did not account for changes in r egional blood flow, which probably indicate early involvement of cereb ral structures.