ABSTRACT
In addition to nocturnal penile tumescence (NPT) and the penile vascular assessment methods (see Chapter 25), neurological assessments can assist in the evaluation of the degree and nature of organic sexual dysfunction (Fig. 1A-D). Although the erectile process is primarily a vascular phenomenon, it is mediated by complex neural mechanisms involving the sacral reflexogenic erection center (parasympathetic) and the thoracolumbar psychogenic erection center (sympathetic) in a unique coordination of the somatic and autonomic motor nervous systems (1). Interruption of any of these pathways can result in erectile dysfunction. For example, decreased sensibility of the penis may be the sole factor causing an inability to sustain erection; similarly, impaired function of the pudendal nerve may be accountable (2). It is important to note that erectile dysfunction is commonly associated with both urologic and neurological abnormalities, and the treatment of urovascular dysfunction with, e.g., revascularization may not be sufficient or even indicated in patients with severe neurological disturbances (3).
