Neural Substrates of Motor Recovery in Severely Impaired Stroke Patients With Hand Paralysis

This is so godammed obvious, you look at the dead areas of the brain. Did the dead area formerly control hand function? If so then recovery is unlikely to happen easily. My motor control area for the hand seems to be dead and likewise the premotor cortex is mostly dead. My hand recovery is almost non-existent. It requires moving and finding neurons somewhere else to take over that functionality. It has  never been identified how to do that.
http://nnr.sagepub.com/content/30/4/328?etoc

1. Michelle L. Harris-Love, PhD1,2⇑
2. Evan Chan, MS2
3. Alexander W. Dromerick, MD1,2,3
4. Leonardo G. Cohen, MD4

1. ¹Georgetown University Medical Center, Washington, DC, USA
2. ²MedStar National Rehabilitation Hospital, Washington, DC, USA
3. ³District of Columbia VA Medical Center, Washington, DC, USA
4. ⁴Human Cortical Physiology and Neurorehabilitation Section, NINDS, NIH, Bethesda, MD, USA

1. Michelle L. Harris-Love, PhD, 102 Irving Street NW, Room 1058, Washington, DC 20010, USA. Email: Mh672@georgetown.edu

Abstract

In well-recovered stroke patients with preserved hand movement, motor dysfunction relates to interhemispheric and intracortical inhibition in affected hand muscles. In less fully recovered patients unable to move their hand, the neural substrates of recovered arm movements, crucial for performance of daily living tasks, are not well understood. Here, we evaluated interhemispheric and intracortical inhibition in paretic arm muscles of patients with no recovery of hand movement (n = 16, upper extremity Fugl-Meyer Assessment = 27.0 ± 8.6). We recorded silent periods (contralateral and ipsilateral) induced by transcranial magnetic stimulation during voluntary isometric contraction of the paretic biceps and triceps brachii muscles (correlates of intracortical and interhemispheric inhibition, respectively) and investigated links between the silent periods and motor recovery, an issue that has not been previously explored. We report that interhemispheric inhibition, stronger in the paretic triceps than biceps brachii muscles, significantly correlated with the magnitude of residual impairment (lower Fugl-Meyer scores). In contrast, intracortical inhibition in the paretic biceps brachii, but not in the triceps, correlated positively with motor recovery (Fugl-Meyer scores) and negatively with spasticity (lower Modified Ashworth scores). Our results suggest that interhemispheric inhibition and intracortical inhibition of paretic upper arm muscles relate to motor recovery in different ways. While interhemispheric inhibition may contribute to poorer recovery, muscle-specific intracortical inhibition may relate to successful motor recovery and lesser spasticity.