Anorectal functions in patients with spinal cord injury

We wished to establish anorectal functions in patients with spinal cord les ions, related to the level of lesion and its completeness. We also wished t o determine the value of neurophysiological tests for completeness of trans sections in comparison with manometry and visceral sensory testing. In 32 patients (31.5 +/- 14.1 years, 25 males) with spinal trauma, complete ness of transsection was assessed clinically. In 16 of these patients (30 /- 15.6 years, nine males), a neurological work-up included recording of so matosensory evoked potentials (SEP) and motor evoked potentials (MEP) from the pudendal nerve within the first week after trauma. Also, anal sphincter EMG and pudendal nerve terminal motor latency (PNTML) were assessed. All p atients also underwent conventional anorectal manometry and visceral sensor y testing. Of all 32 patients, 15 were judged as 'complete' based on their clinical si gns. Of those 16 tested neurologically, seven were labelled 'complete' sinc e no MEP or SEP were detectable; one had pudendal SEP and MEP present, whil e SEP were present but delayed (47.0 +/- 8.8 msec) in the remaining patient s. In four of these patients, also MEP were recorded (27.9 +/- 5.2 msec) an d normal. PNTML was present in 12/16 patients independent of the completene ss of lesion, and was rated normal in nine and delayed in three patients. E MG was normal in five, and pathological in 11 cases. In 5/15 cases of those judged as 'complete' (in 3/7 evaluated neurologically), visceral sensory t esting revealed a minimal threshold for rectal perception of distension of 44 mL (range: 10-130), which sometimes was also perceived as urge to defeca te. In a further case, manometry showed major voluntary action of the anal sphincter. These patients had lesions at all levels of the spinal column, r anging from cervical (C4,C6,C7) via thoratical (2 x T7,T8,T12) to lumbar se gments. Anorectal function testing, and specifically visceral sensory testing may b e superior to neurological assessment of 'completeness' of spinal cord lesi ons. It may be that visceral afferent pathways others than spinothalamic tr act are involved in rectal perception that are less accessible to conventio nal neurophysiological diagnostic work-up.