Figure 1.

Neurophysiological basis of cough and epidural stimulation of the lower thoracic spinal cord. The expiratory internal intercostal muscles are innervated by their respective segmental intercostal nerves and the abdominal muscles are innervated via the lower intercostal branches (thoracoabdominal nerves), as well as regional branches from the lumbar plexus (i.e., ilioinguinal and iliohypogastric nerves). Based on the reviewed literature a putative target location for an epidural electrode is shown for lower thoracic spinal cord stimulation (SCS). Co-stimulation of the lower thoracic (e.g., T9) and upper lumbar (e.g., L1) spinal levels have shown to recruit the expiratory muscles and generate high peak expiratory pressures and air flow.