Post-stroke changes in cortical 5-HT2 serotonergic receptors.

Fluorine-18-setoperone PET imaging was used to investigate serotonergic 5-HT2-specific binding in unlesioned cerebral cortex in stroke patients.

METHODS

Seventeen stroke patients (mean age 50 +/- 31 yr) with right (n = 9) or left (n = 8) chronic stroke (middle or anterior cerebral artery territory) underwent [18F]setoperone PET and MR imaging. The distribution volume of the 5-HT2-specific binding at equilibrium (DVSe) was determined in the unlesioned cortical regions. The results were 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 covariance 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 stroke and did not correlate with the volume of the stroke. However, the localization of the stroke affected the topography of DVSe abnormalities. When the lesion did not extend more medially than the internal capsule, DVSe was significantly reduced in the temporal lobe (-30%, p < 0.05) but not in the frontal lobe (-21%, p = ns). Conversely, when the lesion extended subcortically in the anteromedial region, close to the midline, DVSe was reduced in both temporal (-40%, p < 0.05) and frontal (- 49%, p < 0.05) lobes.

CONCLUSIONS

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.