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Motor cortex activation is preserved in patients with chronic hemiplegic stroke
Author(s) -
Cramer Steven C.,
Mark Angela,
Barquist Kristin,
Nhan Hoang,
Stegbauer Keith C.,
Price Robert,
Bell Kathleen,
Odderson Ib R.,
Esselman Peter,
Maravilla Kenneth R.
Publication year - 2002
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.10351
Subject(s) - corticospinal tract , motor cortex , neuroscience , stroke (engine) , pyramidal tracts , psychology , physical medicine and rehabilitation , cerebral cortex , cortex (anatomy) , proprioception , medicine , magnetic resonance imaging , stimulation , diffusion mri , mechanical engineering , engineering , radiology
Many central nervous system conditions that cause weakness, including many strokes, injure corticospinal tract but leave motor cortex intact. Little is known about the functional properties of surviving cortical regions in this setting, in part because many studies have used probes reliant on the corticospinal tract. We hypothesized that many features of motor cortex function would be preserved when assessed independent of the stroke‐affected corticospinal tract. Functional MRI was used to study 11 patients with chronic hemiplegia after unilateral stroke that spared regions of motor cortex. Activation in stroke‐affected hemisphere was evaluated using 3 probes independent of affected corticospinal tract: passive finger movement, a hand‐related visuomotor stimulus, and tapping by the nonstroke index finger. The site and magnitude of cortical activation were similar when comparing the stroke hemisphere to findings in 19 control subjects. Patients activated each of 8 cortical regions with similar frequency as compared to controls, generally with a smaller activation volume. In some cases, clinical measures correlated with the size or the site of stroke hemisphere activation. The results suggest that, despite stroke producing contralateral hemiplegia, surviving regions of motor cortex actively participate in the same proprioceptive, visuomotor, and bilateral movement control processes seen in control subjects.