Article

OBJECTIVE: To use transcranial magnetic stimulation and electromyography to
assess the potential for preserved function in the abdominal muscles in
individuals classified with motor-complete spinal cord injury above T6. SUBJECTS:
Five individuals with spinal cord injury (C5-T3) and 5 able-bodied individuals.
METHODS: Transcranial magnetic stimulation was delivered over the abdominal
region of primary motor cortex during resting and sub-maximal (or attempted)
contractions. Surface electromyography was used to record motor-evoked potentials
as well as maximal voluntary (or attempted) contractions in the abdominal muscles
and the diaphragm. RESULTS: Responses to transcranial magnetic stimulation in the
abdominal muscles occurred in all spinal cord injury subjects. Latencies of
muscle response onsets were similar in both groups; however, peak-to-peak
amplitudes were smaller in the spinal cord injury group. During maximal voluntary
(or attempted) contractions all spinal cord injury subjects were able to elicit
electromyography activity above resting levels in more than one abdominal muscle
across tasks. CONCLUSION: Individuals with motor-complete spinal cord injury
above T6 were able to activate abdominal muscles in response to transcranial
magnetic stimulation and during maximal voluntary (or attempted) contractions.
The activation was induced directly through corticospinal pathways, and not
indirectly by stretch reflex activations of the diaphragm. Transcranial magnetic
stimulation and electromyography measurements provide a useful method to assess
motor preservation of abdominal muscles in persons with spinal cord injury.

Langue : ANGLAIS