POSTSTROKE CHANGES IN CORTICAL 5-HT2 SEROTONERGIC RECEPTORS

Fluorine-18-setoperone PET imaging was used to investigate serotonergi c 5-HT2-specific binding in unlesioned cerebral cortex in stroke patie nts. Methods: Seventeen stroke patients (mean age 50 +/- 31 yr) with r ight (n = 9) or left (n = 8) chronic stroke (middle or anterior cerebr al artery territory) underwent [F-18]setoperone PET and MR imaging. Th e distribution volume of the 5-HT2-specific binding at equilibrium (DV Se) was determined in the unlesioned cortical regions. The results wer e compared with those obtained in 14 age-matched controls. In addition , we investigated the effect of the side of the stroke, lesion volume and its localization. Results: After removing the age effect by covari ance analysis, we found a significant DVSe decrease in the temporal (p < 0.05) and frontal (p < 0.05) unlesioned cortices ipsilateral to the stroke. The changes were similar in patients with left and right stro ke and did not correlate with the volume of the stroke. However, the l ocalization of the stroke affected the topography of DVSe abnormalitie s. When the lesion did not extend more medially than the internal caps ule, DVSe was significantly reduced in the temporal lobe (-30%, p < 0. 05) but not in the frontal lobe (-21%, p = ns). Conversely, when the l esion extended subcortically in the anteromedial region, close to the midline, DVSe was reduced in both temporal (-40%, p < 0.05) and fronta l (-49%, p < 0.05) lobes. Conclusion: This study confirms that stroke may alter 5-HT2 receptors in large unlesioned cortical areas and that the changes depend on the subcortical extent of the lesion.