THALAMIC METABOLISM AND CORTICOSPINAL TRACT INTEGRITY DETERMINE MOTORRECOVERY IN STROKE

We studied the role of remote metabolic depressions and pyramidal trac t involvement regarding motor recovery following a first hemiparetic i schemic stroke. In 23 patients the regional cerebral glucose metabolis m (rCMRGlu) was measured with positron emission tomography and the loc ation and spatial extent of the stroke lesions were assessed by magnet ic resonance imaging. Motor impairment during the acute and chronic st ages (4 weeks after stroke) was determined by a motor score and record ings of magnetic evoked motor potentials. Twelve patients recovered si gnificantly, whereas 11 patients retained a disabling hemiparesis. In contrast to patients with good motor recovery, rCMRGlu was severely de pressed in the thalamus on the lesion side in patients with poor motor recovery. This patient group also showed more severe damage to the py ramidal tract on magnetic resonance images and a more pronounced reduc tion of the magnetic evoked motor potential amplitude. Neither the siz e of the stroke lesions nor the spatial extent of the lesional and rem ote rCMRGlu depressions outside the thalamus correlated with the thala mic hypometabolism and the improvement of the motor score. We conclude that preservation both of parts of the pyramidal tract and of the tha lamic circuitry is a major determinant for the quality of hand motor r ecovery following acute brain ischemia in the adult.