Changes in metabolism of cerebral glucose after stereotactic leukotomy for refractory obsessive-compulsive disorder: a case report.

Brain glucose metabolism was investigated with PET and [18F]fluorodeoxyglucose, before and after a bifrontal stereotactic leukotomy in a 37 year old woman with refractory obsessive-compulsive disorder. A bilateral decrease in glucose metabolism was found in the orbital frontal cortex after psychosurgery. Glucose metabolism was decreased to a lesser degree in Brodmann's area 25, in the thalamus, and in the caudate nucleus. Clinical improvement in obsessive-compulsive disorder after stereotactic tractotomy seems to be associated with metabolic changes in the brain, in particular, in the orbital part of the frontal lobe

HMPAO SPECT in Parkinson's disease before and after levodopa: correlation with dopaminergic responsiveness.

Regional cerebral perfusion was evaluated by SPECT with technetium 99m hexamethylpropyleneamine oxime (99mTc HMPAO) as a tracer in 21 patients presenting with Parkinson's disease and in 11 normal controls. In the parkinsonian patients, scans were performed both off treatment, and after levodopa, and clinical dopaminergic responsiveness was evaluated. Uptake of HMPAO by the basal ganglia was significantly decreased in the parkinsonian subjects, compared with normal controls. This reduction was seen in both responders (n = 14) and non-responders (n = 7) to dopaminergic treatment. Uptake of HMPAO by the basal ganglia rose after treatment with levodopa, but the change was similar in both responders and non-responders. By contrast a striking difference in cortical HMPAO uptake was found between responders and non-responders, with significantly lower uptake in the medial temporal and posterior parietal cortex in the non-responders. This reduction was symmetrical. Basal ganglia perfusion assessed by this technique is unlikely to be of use in the diagnosis of Parkinson's disease that is responsive to dopaminergic treatment. The presence of extensive cortical involvement on a baseline scan correlates with a lack of dopaminergic responsiveness, however, and this may be useful diagnostically