Article

This study compared bilateral corticomotor and intracortical
excitability of the primary motor cortex (M1), pre- and post-unilateral
transtibial amputation. METHOD: Three males aged 45, 55, and 48 years
respectively who were scheduled for elective amputation and thirteen (10 male, 3
female) healthy control participants aged 58.9 (SD 9.8) were recruited.
Transcranial magnetic stimulation assessed corticomotor and intracortical
excitability of M1 bilaterally. Neurophysiological assessments were performed 10
(SD 7) days prior to surgery and again at 10 (SD 3) days following surgery. Data
were analyzed descriptively and objectively compared to 95% confidence intervals
from control data. RESULTS: Prior to amputation, all three patients demonstrated
stronger short-latency intracortical inhibition evoked from M1 ipsilateral to the
affected limb and reduced long-latency intracortical inhibition evoked from M1
contralateral to the affected limb compared to control subjects. Following
amputation, short-latency intracortical inhibition was reduced in both M1s and
long-latency intracortical inhibition was reduced for the ipsilateral M1.
Single-pulse motor evoked potential amplitude and motor thresholds were similar
pre-to-post amputation. CONCLUSIONS: Modulation of intracortical excitability
shortly following amputation indicates that the cortical environment may be
optimized for reorganization in the acute post-amputation period which might be
significant for learning to support prosthetic mobility. Implications for
Rehabilitation Amputation of a lower-limb is associated with extensive
reorganization at the level of the cortex. Reorganization occurs in the acute
post-amputation period implying a favorable cortical environment for recovery.
Rehabilitation or brain interventions may target the acute pre-prosthetic
post-amputation period to optimize recovery.

Langue : ANGLAIS