ABSTRACT
Classification of neurogenic voiding dysfunction The main objective in assessing patients with suspected neurogenic lower urinary tract (LUT) dysfunction is to determine what effect the neurologic disease has on the entire urinary tract so that treatment can be implemented to relieve symptoms and prevent upper and lower urinary tract damage. The functional classification system described by Wein (Figure 8.1) is a useful framework with which to conceptualize neurogenic voiding dysfunction and provides a basis for the discussion of various diagnostic and treatment modalities.1 This simple and practical system can be easily applied to our diagnostic criteria (e.g. urodynamics). Of equal importance is the fact that treatment options can be chosen based on this system. The functional classification system is based on the simple concept that the LUT has two basic functions: storage of adequate volumes of urine at low pressures, and voluntary and complete evacuation of urine from the bladder. For normal storage and emptying to occur there must be proper and
coordinated functioning of the bladder and bladder outlet (bladder neck, urethra, external sphincter). Hence, neurogenic LUT dysfunction can be classified under the following rubrics: ‘failure to store’, ‘failure to empty’, or a combination thereof. Abnormalities in LUT function may be the result of bladder dysfunction, bladder outlet dysfunction, or a combined dysfunction. Figure 8.2 summarizes how neurologic disease can adversely affect the bladder and/or the bladder outlet, causing storage and emptying dysfunction.
