Do you see secondary EMG/NCS abnormalities in patients with chronic upper motor neuron dysfunction such as cerebral palsy, myelopathy, or remote stroke?  

The short answer is NO. UMN deficits result in low firing rates, leading to fewer activated motor units, but this does not constitute denervation. Nonetheless, the concept of trans-synaptic degeneration has been discussed for over 50 years (I believe Dr. Wilder Penfield, the neurosurgeon from Montre...