Affiliations: Department of Physical Medicine and Rehabilitation,
College of Medicine, Yeungnam University, Republic of Korea | Department of Physical Therapy, Yonsei University
College of Health Science, Republic of Korea | Department of Physical Medicine and Rehabilitation,
College of Medicine Pochon Jungmoon University, Bundang CHA General Hospital,
Sungnam, Republic of Korea | Physical Therapy Program, Hampton University,
USA | Department of Neurosurgery, College of Medicine,
Yeungnam University, Republic of Korea
Note: [] Corresponding author: Sang-Hyun Cho, Department of Physical
Therapy, Yonsei University College of Health Science, Wonju-si, Kangwon-do,
220-710, Republic of Korea. Tel.: +82 11 366 8043; Fax: +82 33 760 2496;
E-mail: davinci@dragon.yonsei.ac.kr
Abstract: Purpose: The purpose of this study was to investigate the motor
recovery mechanism following diffuse axonal injury (DAI) using transcranial
magnetic stimulation (TMS) and functional MRI (fMRI). Methods: Twenty-six hands of 13 control subjects and 14 affected
hands of 8 patients (two hemiparetics and six quadriparetics) were evaluated.
All the patients were initially diagnosedwith DAIand were evaluated after they
had reached their maximal motor recovery. fMRI was performed at 1.5 T using a
hand grasp-release movement paradigm and TMS was applied with a round coil over
the vertex. Results: fMRI revealed that both normal subjects and patients with
DAI showed increased contralateral primary sensori-motor cortex activation
during affected hand movement.The motor evoked potentials (MEPs) of the patient
group was slightly delayed in latency and significantly increased in duration
and turns. The relative MEP amplitude, phase, and excitatory threshold were not
significantly different between the groups. Conclusions: These findings may indicate the heterogeneity of the
axons in the recovery process of the corticospinal tract. It seems that the
motor recovery in patients who had suffered DAI was attributable to the
recovery of the corticospinal tract.
Keywords: diffuse axonal injury, functional MRI, Magnetic stimulation, Motor recovery
