¹Department of Neurosurgery, University Hospital Maastricht, Maastricht, The Netherlands

Correspondence: Y Temel, MD, Department of Neurosurgery, University Hospital Maastricht, PO Box 5800, Maastricht 6202 AZ, The Netherlands. E-mail: yasintemel@yahoo.com

Received 3 October 2003; Revised 17 February 2004; Accepted 16 March 2004; Published online 15 April 2004.

Abstract

Penile erection is a complex neurovascular event. The neuronal system involved is often divided into a spinal (generator) and supraspinal (controller) network. Little is known about the supraspinal control. The recent finding of changes in penile erection following deep brain stimulation of the thalamus in two patients has raised the question as to what extent the thalamus is involved in erectile function. The thalamus has generally been regarded as a group of relay nuclei that served as a 'gate' for sexual information from the spinal cord towards higher centres. Recent evidence, however, suggests a more integrated regulatory function. Our review of the literature from 1960 until 2003 revealed 13 reports describing original data (preclinical and clinical). Various thalamic regions, varying from the midline thalamus to the posterior thalamus, have been reported to be activated during erection. The majority of the reports, however, showed that mainly the mediodorsal (MD) nucleus and the centromedian–parafascicular nucleus (Cm–Pf complex) are involved in penile erection. MD is the second largest nuclear aggregation located within the medial part of the thalamus. Anatomically, the MD is closely related to the Cm–Pf complex. The Cm–Pf complex is one of the most important relay stations in which the anterolateral spinothalamic pathway is further processed. This pathway is thought to transmit peripheral sexual sensations. On the whole, the present data on the role of the thalamus in erection are far from complete and future experiments are required to delineate its involvement.