Positron emission tomography was used to study the effects of unilateral vascular thalamic lesions on cortical oxygen and glucose utilization in 10 patients. There was significant ipsilateral cortex hypometabolism in 9 of the 10 patients, affecting the whole cortical mantle diffusely. The only patient spared was free of neuropsychological deficit at the time of positron emission tomography. In 4 patients, the magnitude of ipsilateral cortical hypometabolism was significantly less at a follow-up PET study, when neuropsychological function had improved When taken together, the 14 studies showed a significant tendency for the hypometabolism to improve with taken together, the 14 studies showed a significant tendency for the hypometabolism to improve with time after clinical onset. These data suggest that the ipsilateral cortical hypometabolism results from damage to the thalamo-cortical connections and reflect either loss of nonspecific activating afferences or a degenerative deafferentation-deefferentation process, or both. Its links with the concept of diaschisis are suggested by its tendency to recover. A causal relationship between cortical hypometabolism and neuropsychological deficit, however, although strongly suggested, cannot be firmly established from the present data.
ASJC Scopus subject areas
- Statistics, Probability and Uncertainty
- Applied Mathematics
- Statistics and Probability
- Agricultural and Biological Sciences (miscellaneous)
- Clinical Neurology