Repetitive Transcranial Magnetic Stimulation of the Contralesional Dorsal Premotor Cortex for Upper Extremity Motor...

The aim of the study was to compare the effects of repetitive transcranial magnetic stimulation targeting the contralesional dorsal premotor versus the ipsilesional primary motor cortex in chronic stroke survivors with severe hand paresis.

This assessor-blinded pilot randomized trial enrolled 16 participants ≥6 mos after stroke with severe hand paresis, defined by the absence of either 10° distal extension in wrist/fingers/thumb or motor evoked potentials in paretic muscles. Participants received 5-Hz repetitive transcranial magnetic stimulation to the contralesional dorsal premotor or the ipsilesional primary motor cortex target, combined with upper extremity rehabilitation for 6 wks. Outcomes included Upper Extremity Fugl-Meyer, Wolf Motor Function Test, Stroke Impact Scale-16, and interhemispheric inhibition.

Baseline characteristics were similar across groups, although the ipsilesional stimulation group had more participants with motor evoked potentials and ≥10° thumb extension (P = 0.04). Both groups achieved similar gains on Fugl-Meyer, but wrist subscore changes favored the ipsilesional stimulation group (P = 0.011). No differences were observed for other outcomes.

Stimulation of the contralesional dorsal premotor cortex was not superior to stimulation of the ipsilesional primary motor cortex for upper extremity rehabilitation outcomes in chronic stroke survivors with severe hand paresis, though both approaches yielded sustained motor improvements. Future trials should stratify by distal extension and physiology.