Functional effects of striatal dysfunction in Parkinson disease
V. A. Holthoff-Detto, J. Kessler, K. Herholz, H. Bonner, U. Pietrzyk, M. Wurker, M. Ghaemi, K. Wienhard, R. Wagner and W. D. Heiss
Max-Planck-Institut fur Neurologische Forschung, Koln, Germany.
BACKGROUND: Concepts of basal ganglia organization suggest structually and
functionally segregated pathways that link putamen and caudate function to
motor and cognitive performance, respectively. OBJECTIVE: To investigate
whether motor and cognitive impairment in Parkinson disease is attributable
to selective disturbance in nigrostriatal, dopaminergic function and
regional cerebral glucose metabolism. DESIGN: Twenty patients with probable
Parkinson disease underwent positron emission tomographic measurements of
dopaminergic, nigrostriatal function (positron emission tomography with
fluorodopa F 18), regional glucose metabolism (positron emission tomography
with fludeoxyglucose F 18), memory testing, and evaluation of locomotor
disability. RESULTS: Memory performance in the patient cohort strongly
correlated with the individual disease duration and degree of locomotor
disability (P < .05). Striatal uptake rates of fluorodopa F 18 were
significantly reduced in all patients (P < .05) compared with those in
normal control subjects, and putaminal rates correlated significantly with
the patients' degree of locomotor disability (P < .01) but not with
memory performance. In the patients with an advanced stage of disease,
there was a significant correlation between reduced caudate uptake rates of
fluorodopa F 18 and the patients' impairment in delayed recall performance
of the memory task (P < .05) but not with the individual degree of
locomotor disability. No changes were found for regional glucose metabolic
rates in the patients compared with the controls. CONCLUSIONS: The present
study provides evidence for the hypothesis that on the level of the
striatum, motor impairment in Parkinson disease may be assigned to altered
dopamine neuronal integrity in the putamen but not in the caudate, whereas
memory impairment in the more advanced cases may be attributed to caudate
but not putaminal dysfunction.
