Decorticate Spasticity: A Re-examination using Quantitative Assessment in the Primate

SUMMARY:Decorticate spasticity in the squirrel monkey was chosen as a convenient laboratory model of spasticity capable of quantitative assessment upon which to evaluate various currently popular clinical spasmolytic measures. The effects of a wide variety of cortical lesions were studied involving primary and supplementary motor, premotor and parietal cortex unilaterally and bilaterally, measuring muscle tone with the evoked integrated E.M.G. technique. Measurable spasticity resulted only if primary motor cortex was ablated bilaterally usually but not always preferentially involving biceps brachii and quadriceps. Resulting postures were variable offering no justification for the term “decorticate posture”. The integrated evoked E.M.G. was proportional to rate of stretch and chiefly phasic in type as in hemiplegic man. Stereotactic dentatectomy resulted in profound ipsilateral reduction in this spasticity, but was without effect in intercollicular or anemic decerebrate cats. The mechanism of the spasticity and of the cerebellar effects are discussed.</jats:p

Correlation of CT and MR with Impedance Monitoring and Histopathology in Stereotactic Biopsies

ABSTRACT:Magnetic Resonance Imaging (MR) and Computer Assisted Tomography (CT) guided stereotaxis combined with intraoperative impedance monitoring and multiple sequential biopsies provides the opportunity to correlate the results of radiologic imaging with impedance and histopathology. The authors present the methods used and preliminary results obtained from 30 stereotactic biopsies with complete correlation in 12 cases. Impedance changes correlate accurately with lesion margins as defined by histology. CT images of enhancing lesions correlate quite closely to the histopathologic lesion margins whereas the appearance of the lesion on MR images is often larger than subsequently identified by either impedance or at pathologic examination. Impedance monitoring is a useful adjunct to stereotactic biopsy as it helps to accurately define lesion margins and can help direct the choice of biopsy sites.</jats:p