Figure 7.

Thoracic lesion level and severity after human SCI are independently associated with enhanced ‘neurogenic’ risk of SCI-associated pneumonia (SCI-AP). (A) Sympathetic innervation (preganglionic, postganglionic) of immunological relevant organs in humans. SCI rostral to Th5 (Th1–Th4) will result in preganglionic injury to sympathetic efferents whereas Th5–Th8 SCI spares some and SCI Th9–Th12 most sympathetic efferents to the ganglion coeliacum. (B) We compared motor complete (AIS A and B patients, grey bars, given the excellent correspondence between somatic and complete sympathetic lesions in this population) with motor incomplete patients (AIS C and D, white bars) with enhanced sparing of sympathetic outflow. Relative frequency of pneumonia is shown in motor complete versus motor incomplete SCI patients, categorized as high (Th1–Th4), mid (Th5–Th8) or low (Th9–Th12) thoracic injury level. Within the group of Th1–Th4 patients, pneumonia rates are significantly different between motor complete and incomplete patients, whereas no differences between the groups were detectable in lower thoracic levels. Error bars represent 95% CI. Differences within the neurological level categories were assessed with the chi-square test. Patient numbers: motor complete Th1–Th4, n = 317, Th5–Th8 n = 271, Th9–Th12 n = 451; motor incomplete Th1–Th4, n = 41, Th5–Th8 n = 34, Th9–Th12 n = 107.