The corticomotor projection to liminally-contractable forearm muscles in chronic spinal cord injury: a transcranial magnetic stimulation study.

Publication/Presentation Date

4-1-2017

Abstract

STUDY DESIGN: A cross-sectional study in chronic spinal cord injury with cervical lesions (cSCI).

OBJECTIVE: To determine the corticomotor projection and motor cortex organization of paralyzed forearm muscles that presented only liminal voluntary activation.

SETTING: Burke Medical Research Institute, White Plains, NY, USA.

METHODS: We identified ten people with chronic SCI who had a wrist flexor or extensor muscle with a motor power (MP) of 1 over 5. We recorded motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) over the primary motor cortex of the hemisphere contralateral to the target muscle. We measured resting motor threshold (RMT), corticomotor latency (LTY), MEP amplitude (AMP) and performed cortical motor mapping to determine the optimal site (OPT) and map area (AREA). Results were compared with the data from 18 controls.

RESULTS: A MEP in the target muscle was observed for all cSCI cases. LTY was normal, while corticomotor excitability (as determined by RMT and AMP) was reduced in about half of the group. The OPT site of the motor maps was within control range for all cSCI cases, while AREA was reduced in three cases.

CONCLUSIONS: Corticomotor conduction and cortical topography were appreciably normal despite only liminal activation of the target muscle with voluntary effort. Muscles with these characteristics may benefit from a targeted rehabilitation program even in the chronic phase after SCI.

Volume

55

Issue

4

First Page

362

Last Page

366

ISSN

1476-5624

Disciplines

Business Administration, Management, and Operations | Health and Medical Administration | Management Sciences and Quantitative Methods

PubMedID

27995943

Department(s)

Administration and Leadership

Document Type

Article

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