Affiliations: Department of Neurology, University of Tübingen,
Tübingen, Germany | Department of Traumatic Surgery, University of
Tübingen, Tübingen, Germany
Note: [] Heige Topka, MD, Dept. of Neurology, University of
Tübingen, Hoppe- Seyler-Str. 3, 72076 Tübingen, Germany. Tel.: +49
7071 2982141; Fax: +49 7071 295928; E-mail: topka@uni-tuebingen.de.
Abstract: Purpose: Given that SCI leads to substantial changes in
biomechanical properties of the body and to widespread postlesional
reorganization of the motor system as determined by functional imaging studies,
we sought to identify neurophysiological correlations and time course of
reorganization affecting muscles more distant to a SCI. Methods: Two arm
muscles distant to a SCI (T2-L3), M.biceps brachii (BIC), M.abductor pollicis
brevis (APB), were studied in 13 SCI-patients and 15 controls. Motor
thresholds at rest (MT), facilitatory effects on MEP-amplitudes (FE) with
voluntary activation, MEP-amplitudes with maximal stimulation (MA) and
recruitment curves (RC) were measured and correlated with level, age and
severity of the lesion. Follow-up studies (t2) were performed in five patients
with clinical recovery. Results: Patients exhibited smaller MA from activated
BIC, a tendency towards smaller FE and smaller RC-slopes at t1. With clinical
recovery, activated BIC-FE, MA and RC-slopes tended to normalize. Conclusions:
Our data support the hypothesis that postlesional reorganization of the motor
system also involves remote muscles. Considering pattern and time course of
reorganization, we speculate that they appear as sequelae of the trauma,
possibly representing an adaptation of the motor system to an altered
biomechanical status after SCI.
Keywords: Spinal cord injury, transcranial magnetic stimulation, postlesional reorganization, motor system, biomechanical changes
