To the investigators knowledge, this study is the first to analyze changes of corticospinal excitability and reorganization in patients with cervical spondylotic myelopathy with navigated TMS. In the present study, there was a significant difference in parameters of excitability and motor area activation between the severely symptomatic and clinically stable patient group. The investigators analysis showed that chronic CSM induces a recruitment of the non-primary motor area and corticospinal disinhibition, so that axonal damage can be compensated through recruitment of new cortical and supplementary motor connections, to a certain degree. Upon exhaustion of these mechanisms further axonal damage translates directly into new neurological deficits. These results lay the ground for a novel concept in CSM, the "corticospinal reserve capacity".