CEREBRAL NETWORK UNDERLYING UNILATERAL MOTOR NEGLECT - EVIDENCE FROM POSITRON EMISSION TOMOGRAPHY

In 4 male patients (age range 50-73 years) with unilateral motor hemin eglect as a sequelae of circumscribed cerebral infarction, depressions of the regional cerebral glucose metabolism (rCMRGlu) were mapped to identify the metabolically affected cerebral structures. Motor neglect was defined according to Castaigne by lack of spontaneous and pain-in duced motor activity on one side of the body in the absence of paresis , pyramidal signs, and sensory loss. The depressions of the rCMRGlu as determined by positron emission tomography (PET) were found to exceed the areas of structural damage but to be restricted to the affected c erebral hemisphere. Significant mean rCMRGlu depressions followed a fo cal pattern involving the premotor, prefrontal, parietal and cingulate cortex, as well as the thalamus. In correspondence to the lack of sig nificant mean rCMRGlu depressions in primary sensorimotor cortex, basa l ganglia, and cerebellum the cortico-spinal pathway was spared as ind icated by preserved magnetic evoked motor potentials. Our data provide evidence suggesting that motor hemineglect is a disturbance in a cere bral network of higher order cortical areas subserving motor activity in the presence of an intact motor cortical output system.