Pure akinesia with gait freezing (
PAGF) has characteristic features, including freezing of gait and prominent speech disturbance without rigidity or
tremor. The purpose of this study was to investigate changes in brain
glucose metabolism and presynaptic dopaminergic function in
PAGF. By using [(18)F] fluorodeoxyglucose (FDG) PET, 11 patients with
PAGF were compared with 14 patients with probable
progressive supranuclear palsy (PSP), 13 patients with
Parkinson's disease (PD), and 11 normal controls. [(18)F] N-(3-fluoropropyl)-2beta-carbon ethoxy-3beta-(4-iodophenyl) nortropane (
FP-CIT) PET was performed in 11 patients with
PAGF and with 10 normal controls. The
PAGF patients showed decreased
glucose metabolism in the midbrain when compared with normal controls. PSP patients showed a similar topographic distribution of
glucose hypometabolism with additional areas, including the frontal cortex, when compared with normal controls. The
FP-CIT PET findings in patients with
PAGF revealed severely decreased uptake bilaterally in the basal ganglia. These findings suggest that both
PAGF and PSP may be part of the same pathophysiologic spectrum of disease. However, the reason why
PAGF manifests clinically in a different manner needs to be further elucidated.