Complex motor representations may not be preserved after complete spinal cord injury

When using motor imagery to improve rehabilitation after spinal cord injury it is assumed that the motor representations are preserved and that task specific physical training is not necessary. Here I tested this hypothesis by examining P.W. who has a complete spinal cord injury due to an accident. However, P.W. was an elite wheelchair athlete, hence, has experienced a high load of physical training in general. During functional magnetic resonance imaging (fMRI), P.W. imagined wheelchair slalom (a complex motor task P.W. can perform) and stair walking (a complex motor task P.W. no longer can perform). A control group of neurologically intact participants were also included. The results showed that only for the task (wheelchair slalom) P.W. currently could physically perform was the pre-motor cortex recruited. For stair walking P.W. recruited inferior frontal cortex and parietal cortex. The results were confirmed with the control group showing similar pattern but for the opposite tasks. The conclusions from this study are that complex motor representations may not be preserved after a complete spinal cord injury and motor imagery is dependent on the current ability to perform the task physically.