Unilateral voluntary hand movement and regional cerebral uptake of technetium-99m-exametazime in human control subjects.

The study examines the sensitivity of a region of interest approach to detect functional changes in brain metabolism with SPECT and split-dose 99mTc-exametazime by replicating a simple hand movement experiment previously carried out with PET. Regional uptake of 99mTc-exametazime was determined in 12 healthy controls before and during a thumb-digit opposition task. Analysis of regional uptake was carried out blind to the hand used in the opposition task and showed a significant unilateral activation effect in a pericentral region of interest with opposite results in left- and right-handed activation. The maximum contralateral increase in tracer uptake was 16% before and 26% after correction for back diffusion. This is in good agreement with previous results employing absolute cerebral blood flow determination with PET and confirms the usefulness of 99mTc-exametazime SPECT for the examination of functional metabolic changes.