Striatal hypometabolism distinguishes striatonigral degeneration from Parkinson's disease

Regional and global metabolic rates for glucose were estimated using 18F‐fluorodeoxyglucose and positron emission tomography in 10 patients with a clinical likelihood of striatonigral degeneration (2 men and 8 women; mean age, 61.8 ± 6.9 years; mean disease duration, 4.7 ± 2.2 years; mean Hoehn and Yahr score, 3.5 ± 0.8). Measures of brain glucose metabolism in these patients were compared with those for 10 age‐matched normal volunteers, 10 disease severity–matched patients with Parkinson's disease(PD), and 10 disease duration–matched patients with PD. Normalized glucose metabolism was significantly reduced in the caudate(p < 0.03) and putamen (p < 0.003) as compared with that in normal and PD control subjects, and discriminated patients with striatonigral degeneration from control subjects (p < 0.002). Putamenal hypometabolism in patients with striatonigral degeneration correlated significantly with quantitaive ratings of motor disability (p < 0.02). These results suggest that quantitative 18F‐fluorodeoxyglucose positron emission tomography techniques may be useful in supporting a diagnosis of striatonigral degeneration in life, and in objectively assessing disease severity and potential therapeutic interventions.