Bladder Managment for Adults with Spinal Cord Injury - 15

CLINICAL PRACTICE GUIDELINE

sphincter dyssynergia is common in those with suprasacral SCI. The net effect of the cerebral cortex on micturition is inhibitory to the sacral micturition center. Because suprasacral SCI also disrupts the inhibitory impulses from the cerebral cortex, those with suprasacral SCI frequently have small bladder capacities with involuntary (uninhibited) bladder contractions.

C l a s s i f i c a t i o n o f Vo i d i n g Dysfunction
SUPRAPONTINE LESIONS

suprasacral lesions. DESD is defined as intermittent or complete failure of relaxation of the urinary sphincter during a bladder contraction and voiding. It has been reported to occur in 96 percent of individuals with suprasacral lesions. In addition to DESD, internal sphincter dyssynergia also has been reported, often occurring at the same time as detrusor-external sphincter dyssynergia. In this guideline the term detrusor sphincter dyssynergia will be used throughout to refer to the entire sphincter mechanism—internal and external sphincter.
SACRAL LESIONS

Any suprapontine lesion may affect voiding. Lesions may result from cerebrovascular disease, hydrocephalus, intracranial neoplasms, traumatic brain injury, Parkinson’s disease, and multiple sclerosis. The expected urodynamic finding following a suprapontine lesion is detrusor hyperreflexia (overactive bladder) without detrusor sphincter dyssynergia (DSD). Normally the sphincter should remain relaxed during the bladder contraction. Detrusor sphincter dyssynergia occurs when the sphincter intermittently tightens during the contraction. It is important to note that the voiding dysfunction may be very different from expectations due to various factors, such as medications, prostate obstruction, and possible normal bladder function but poor cognition.
SUPRASACRAL SPINAL CORD LESIONS

Traumatic suprasacral SCI results in an initial period of spinal shock, during which there is detrusor areflexia. During this phase, the bladder has no contractions. The neurophysiology for spinal shock and its recovery is not known. Recovery of bladder function usually follows recovery of skeletal muscle reflexes. Uninhibited bladder contractions gradually return after 6 to 8 weeks. Clinically, a person with a traumatic suprasacral SCI may begin having episodes of urinary incontinence and various visceral sensations, such as tingling, flushing, increased lower extremity spasms, or autonomic dysreflexia with the onset of uninhibited contractions. As uninhibited bladder contractions become stronger, the post-void residuals (PVRs) decrease. Eventually these individuals develop uninhibited contractions Unfortunately, high intravesical voiding pressures usually are required for the development of a balanced bladder. It has been found that high voiding pressures and prolonged duration of the bladder contractions may cause hydronephrosis and renal deterioration. Urodynamic studies are used to determine these voiding parameters. Detrusor-external sphincter dyssynergia (DESD) also commonly occurs following

A variety of lesions can affect the sacral cord or roots. Damage to the sacral cord or roots generally results in a highly compliant acontractile bladder; however, particularly in individuals with partial injuries, the areflexia may be accompanied by decreased bladder compliance resulting in progressive increases in intravesical pressure with filling (Herschorn and Hewitt, 1998). The exact mechanism by which sacral parasympathetic decentralization of the bladder causes decreased compliance is unknown. It has been noted that the external sphincter is not affected to the same extent as the detrusor. This is because the pelvic nerve innervation to the bladder usually arises one segment higher than the pudendal nerve innervation to the sphincter. Also, the nuclei are located in different portions of the sacral cord, with the detrusor nuclei located in the intermediolateral cell column and the pudendal nuclei located in the ventral gray matter. This combination of detrusor areflexia and an intact sphincter helps contribute to bladder overdistention and decompensation.

U ro l o g i c E v a l u a t i o n
Generally, a urologic evaluation is done every year, although there is no consensus among doctors on the frequency this type of exam should be performed or the range of tests that should be included. The important components of the urologic evaluation are an assessment of both the upper and lower tracts. Upper tract evaluations include tests that evaluate function, such as renal scans and tests that evaluate anatomy, such as ultrasound, CT scans, and intravenous pyelograms (IVP). Renal scans are frequently used to screen the upper tract because they are not user dependent, do not have a risk of allergic reactions, do not require a bowel prep, and cause much less radiation exposure than a CT scan or IVP . Lower tract evaluations include urodynamics to determine bladder function, cystograms to eval-

Bladder Managment for Adults with Spinal Cord Injury

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