The neurovisceral and electrodiagnostic evaluation of patients with thoracic spinal cord injury

Abstract

SutntnaryWe studied nine patients with complete thoracic spinal cord injury in order to investigate distal electrophysiologic and end organ function. Studies included motor and sensory nerve conduction velocities, spinal and cortical somatosensory evoked responses, bulbocavernosus reflex responses, cystometry and colonic compliance, motor and myoelectrical activity. These studies confirmed an intact peripheral nervous system, as well as normal nerve root, cauda equina, conus medullaris and distal spinal cord function. Cystometry demonstrated decreased bladder capacity and inability to suppress detrusor contractions. Colonic compliance was greatly reduced, compared to control subjects. While basal colonic motor and myoelectrical activity was normal, these spinal cord injury patients failed to demonstrate the postprandial increase in colonic motor and myoelectric activity seen in normal subjects. These tests allow the clinician to define and document the extent of neuronal injury distal to a transverse myelopathy and to evaluate visceral end organ function.

Relationship between gut-specific autonomic testing and bowel dysfunction in spinal cord injury patients

“…[9][10][11][12][13] SCI patients lose a variable proportion of their extrinsic autonomic innervation to their gut, depending on the level of injury, whereas the intrinsic enteric nervous system remains intact. 3 The gut intrinsic nervous system may lose integrity with time because of the loss of extrinsic supply.…”

Constipation-related symptoms and bowel program concerning individuals with spinal cord injury

“…Benzodiazepines have not previously been shown to increase the risk of constipation in non-injured subjects 33,37 and this study ®nding may be confounded by increased administration to individuals who are Frankel grade A or B. The ®nding that individuals with history of previous urinary outlet surgery had a greater risk of reporting di culty with evacuation may re¯ect the shared innervation between bladder and lower gut; hyperre¯exic volume-pressure abnormalities have been documented in both the colon and bladder in individuals with cervicothoracic lesions, 8,9,23 and persons with anorectal dyssynergia also tend to have concomitant bladder detrusorsphincter dyssynergia. 3 Stone et al found that 72% of individuals with di culty with evacuation had had transurethral sphincterotomy.…”

“…Physiological studies have generally shown that the postprandial increase in colonic spike potentials corresponding to the gastrocolic re¯ex, is absent in individuals with cervicothoracic lesions. 8,9,47 However, these clinical ®ndings would suggest that patients should nevertheless be encouraged to administer their bowel program within 45 min of ingesting a meal, or hot or carbonated¯uids.…”

“…Constipation inevitably follows complete cord transection 2,8,9 or conus medullaris injury, 10 and frequently proves resistant to conventional treatment in these individuals. 10 ± 12 Characterization of symptoms associated with constipation in individuals with SCI is limited in the current medical literature, 5 but it appears that the prevalence of constipation-related symptoms, and the negative impact on lifestyle which they cause, increases in relation to the duration of their disability.…”

“…1,10,22 ± 24 Cervicothoracic trauma results in hypertonicity and reduced compli-ance of the entire colon, thereby greatly prolonging transit time from cecum to descending colon. 3,8,9,23,25 However, individual patients with comparable neurological levels of injury may show markedly di erent patterns of constipation. 2,22 In particular, as individuals age with cervicothoracic cord injury, the colon may become progressively more compliant and¯accid, predisposing them to worsening constipation symptoms.…”