Relation between changes in the preparatory brain potential and excitability of the H-reflex, and localization of a focal ischaemic brain lesion.
In the sample of 15 hemiparetics, ischaemic focus was localized cortically 8 times, deep subcortically 7 times. Use was made of a method that permits simultaneously to record both the cortical potential changes associated with preparation for voluntary movement, and excitability changes of the H-reflex. A slightly depressed amplitude of the preparatory brain potential and a relatively satisfactory facilitation of the H-reflex was observed in the light cortical focal brain ischaemia. A striking deformation up to disorganization of the preparatory brain potential and the absence of facilitation of the H-reflex in subjects with deeper subcortical ischaemic foci may be related to an impairment of the generator of the slow preparatory potential (thalamus, mesencephalon) and to a discruption of cooperation in the complex cerebral cortex - middle thalamus.
D000328:Adult; D000368:Aged; D002545:Brain Ischemia / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000503:physiopathology; D005073:Evoked Potentials, Somatosensory; D006181:H-Reflex; D006429:Hemiplegia / Q000503:physiopathology*; D006801:Humans; D008636:Mesencephalon / Q000503:physiopathology; D008875:Middle Aged; D012023:Reflex, Monosynaptic; D013788:Thalamus / Q000503:physiopathology