Article

While several recent imaging studies confirm that motor foot areas can still be
activated in complete and chronic paraplegia, it remains unclear whether their
functionality is also maintained or declines after years of "non-use". Force
control is one of the most important and best investigated functions within the
motor cortex. It has been repeatedly reported that the motor cortex is more
active when higher forces have to be applied. We thus addressed the question of
preserved cortical functions by comparing motor force control patterns in the
event-related potentials of 10 motor complete paraplegic subjects and 10 controls
after attempted (paraplegic patients)/executed (healthy controls) ballistic foot
movements with three different force levels. In addition to the peak amplitudes
reflecting force levels, peak latencies were also investigated to elucidate
timing as another functional aspect of motor control. No significant group
difference was found for the peak latencies, indicating that the timing of motor
cortical activation is preserved. Concerning amplitudes, we found preserved
cortical modulation of higher forces but distorted low force modulation,
especially early after injury. These findings thus suggest that important aspects
of cortical control over paralyzed limbs are maintained despite years of
"non-use".

Langue : ANGLAIS

Tiré à part : OUI