Neurologic disorders affecting the anorectum

Morphological abnormalities of the recto-anal inhibitory reflex reflects symptom pattern in neurogenic bowel

BACKGROUND

Bowel dysfunction amongst multiple sclerosis (MS) and spinal cord injury (SCI) patients often manifests as fecal incontinence (FI) or constipation, but the pathophysiology is poorly understood. Anorectal physiology provides an objective assessment of lower bowel functions and is increasingly being used in clinical practice.

AIM

The purpose of this study was to correlate symptoms of bowel dysfunction in patients with spinal cord disease with findings in anorectal physiology. We hypothesized that specific abnormalities will correlate with symptoms: prolonged recto-anal inhibitory reflex in patients with incontinence and decreased rectal mucosal blood flow in patients with constipation.

METHODS

Forty-nine patients with MS (35 with predominant FI and 14 constipation), 46 supraconal SCI (mixed symptom load), and 21 healthy volunteers matched for age and sex were studied. Subjects completed validated constipation and FI symptom questionnaires. Patients underwent standard anorectal physiology, including assessment of rectal mucosal blood flow and recto-anal inhibitory reflex (RAIR).

RESULTS

Severity of constipation correlates significantly with distension sensitivity (urge volume [r = 0.68, p = 0.002] and maximal volume [r = 0.39, p = 0.03]). Severity of constipation also correlated with diminished rectal mucosal blood flow in both patient groups (r = -0.51, p = 0.006). In both groups, constipation correlated with diminished relaxation of the sphincters in the RAIR whilst fecal incontinence correlated with a prolonged duration of RAIR (r = 0.33, p = 0.009) and recovery phase (r = 0.37, p = 0.05).

CONCLUSION

Bowel symptoms in patients with MS and SCI correlate with specific alterations of anorectal physiology. This provides objective assessment of bowel symptoms and may allow tailored treatment to individual patients.

Fecal incontinence and spinal cord abnormalities in seven dogs

Seven dogs with fecal incontinence and abnormal gaits were evaluated. Fecal incontinence was characterized as defecation of normal stools without posturing. Duration of clinical signs prior to evaluation ranged from 5 months to 3 years. Five dogs had upper motor neuron (UMN) paraparesis, and 2 dogs had UMN tetraparesis. With magnetic resonance imaging, spinal cord abnormalities primarily involving the dorsal aspect of the spinal cord were identified in all dogs. Five dogs had focal abnormalities, and 2 dogs had diffuse abnormalities of the spinal cord. Of the dogs with focal spinal cord lesions, 4 had cystic spinal cord abnormalities and 1 had a meningioma. Surgery was performed on all dogs with focal lesions; 4 of the 5 dogs had resolution of fecal incontinence after surgery. Results in these dogs suggest that fecal incontinence can be associated with spinal cord abnormalities and, depending on the characteristics of the lesion, can resolve after surgical treatment of the abnormality.

Diagnosis and management of diabetic autonomic neuropathy

Autonomic neuropathy affects every system in the body including the eye, cardiovascular, respiratory, and gastrointestinal and neurovascular systems. The diagnosis confers an attenuated life expectancy, but much can be done to alleviate symptoms and to address the underlying disorder.