Sexual Dysfunction in Patients with Diabetes Mellitus: The Role of a "Central" Neuropathy.
Sexual behavior involves the complex integration of higher intellectual function, such as associative memory and the experience of drives and motivations, with basic instinctual or reflexive physiological responses coordinated at the spinal level. Previous research in diabetic sexual dysfunction has largely focused on diabetic male erectile dysfunction, emphasizing a peripheral vasculopathy or neuropathy as etiologic factors, although ignoring the more complex neuropsychiatric components of sexual behavior. Following a review of the basic physiology of sexual behavior and evidence in support of a peripheral vasculopathy and/or a peripheral autonomic neuropathy in the cause of diabetic sexual dysfunction, emphasis will then shift to the role of a "central" neuropathy as a contributing component of diabetic sexual dysfunction. Evidence in support of such a view will come from a variety of studies, ranging from basic neuroscience research on forebrain mechanisms of sexual function to the functional brain imaging of human rapid eye movement (REM) sleep, a brain state known to be associated with the periodic occurrence of penile tumescence. An integrative perspective of this research will identify major candidate structures within the brain that may be dysfunctional in diabetic patients and may contribute to the profound sexual dysfunction that characterizes this condition. Major findings as well as deficits in our understanding of the effects of diabetes on female sexual dysfunction will also be highlighted, followed by suggestions for future research in this largely understudied area.