British Journal of Urology (1986), 58,434-435 ' ( ' 1 1986 British Journal of Urology

Penile Erections in Myelomeningocele Patients

D. A. DIAMOND, A. M. K. RICKWOOD and D. G. THOMAS

Urological Department, Alder Hey Children's Hospital, Liverpool; Spinal Injuries Unit, Lodge Moor Hospital, Sheffield; Institute of Urology, London

Summary-Of 52 post-pubertal male myelomeningocele patients, 36 (70%) appeared to have penile erections. In relation to spinal neurology, erections occurred in all of those with a positive anocutaneous reflex, 64% of those with a negative anocutaneous reflex and a level at or below the sympathetic outflow and 14% of those with a negative anocutaneous reflex and a level above the sympathetic outflow. The physiological implications of these findings are discussed.

Now that many spina bifida patients have reached physical maturity, the question of their sexual func- tion deserves attention. We have examined the abil- i ty of male myelomeningocele patients to achieve penile erections and have correlated this with cer- tain features of spinal neurology.

Patients and Methods Fifty-two post-pubertal male myelomeningocele patients aged between 12 and 28 years (me'an 16.8) were studied prospectively. After full neurological examination they were asked whether or not they experienced penile erections and this information was cross-checked with parents' observations.

Results Two boys claimed to have erections, although these had never been observed by parents, while three retarded boys were unaware of erections which had been repeatedly seen by parents. Otherwise

lesions were manifest by sacral sensory sparing and, in three instances only, by motor sparing also. (1) Positive anoeutaneous reflex, neurological level

at or below D10: 21 patients (six incomplete cord lesions); erections claimed in 21 (100%).

(2) Positive anocutaneous reflex, neurological level above D10: six patients (no incomplete cord lesions); erections claimed in six (100%).

(3) Negative anocutaneous reflex, neurological level at or below D10: 11 patients (four incom- plete cord lesions); erections claimed in seven

(4) Negative anocutaneous reflex, neurological level above DIO: 14 patients (no incomplete cord lesions); erections claimed in two (14%), in one instance this being claimed by the patient but never observed by parents.

In the series as a whole, 36 patients (70%) had, or claimed to have had, penile erections.

(64%).

Discussion This study has three limitations. Firstly, urological practices do not see the 20% of myelomeningocele patients fortunate enough to have bladder function; these generally have a minimal neuro-

patients' and parents' observations coincided. are 'Onsidered in four groups

according to whether there was evidence of sacral reflex activity in the form of a positive anocuta-

The

neouS reflex and whether the primary level was above Or the upper limit Of the 'ympathetic Outflow (D1O)* Incomplete cord

logical deficit and are likely to have erections. Secondly, we rely on patients' and parents' obser- vations and even when these agree, we cannot

- Accepted for publication 5 July 1985

exclude the possibility that on occasion they repre- sent expectation rather than reality. Finally, we

434

PENILE ERECTIONS IN MYELOMENINGOCELE PATIENTS 43 5

have considered erections alone and not the stimuli which cause them, whether they are adequate for sexual intercourse or whether ejaculation occurred. We had hoped to cover these topics but found this to be impracticable with adolescents. A series con- fined to adults might prove more rewarding.

The phenomenon of penile erection involves psychological, hormonal, vascular and neuro- logical factors of which only the last is strictly rele- vant to this study. An essential event leading to erection is an increase in blood flow via the internal pudendal arteries and this in turn is regulated by parasympathetic outflow from nuclei located at S2 to S4 and by sympathetic outflow from nuclei located at D10 to L2 (Walsh and Donker, 1982; Lue et al., 1984). The parasympathetic system re- sponds to both local and psychological stimuli, while the sympathetic system responds to psycho- logical stimuli only. In experimental cord lesions in dogs, reflex erections occurred so long as the conus medullaris was intact. Excision of the cord below L2 abolished reflex but not psychogenic erections, while removal of the cord below the mid-thoracic level abolished all erections (Muller, 1906). In spinal cord injured patients, reflex erections are four times more common than psychogenic erec- tions (Bors and Comarr, 1960). In one patient with a level at L1, Kuhn (1950) performed anterior and posterior rhizotomies from L2 downwards, abolishing reflex but not psychogenic erections. In another report, psychogenic erections were not seen in patients with a neurological level at or above D9 (Bors and Comarr, 1960). ,

Our findings generally agree with these obser- vations. The presence of a positive anocutaneous reflex shows integrity of sacral somatic reflex activ- ity and this in turn implies that pelvic parasym- pathetic reflex activity is also intact. In this series there were 38 patients with a positive anocutaneous reflex and/or a neurological level at or below D10 and hence likely to have parasympathetic or sym- pathetic input or both; 34 (89%) of these had erec- tions as opposed to only 14% with a negative anocutaneous reflex and a level above D10. It appears that the parasympathetic pathway is the

more important in that all patients with a positive anocutaneous reflex had erections regardless of whether the sympathetic outflow was likely to be intact or not. Why only a proportion of patients with a negative anocutaneous reflex but an intact sympathetic outflow achieve erections is not clear. Our limited material does not indicate that this re- lates to whether the sympathetic outflow is im- paired (level D10-L2) or quite intact (level below L2) or whether the cord lesion is complete or in- complete, but this deserves further attention. Still more mysterious are those patients claiming erec- tions who are unlikely to have sympathetic or para- sympathetic input. It may be that more objective assessment of erectile activity would resolve this dilemma.

Acknowledgement We thank Mr C. J. R. Woodhouse for permission to study patients under his care.

References Bors, E. and Comarr, E. (1960). Neurological disturbances of

sexual function with special reference to 529 patients with spinal cord injury. Urologicaf Survey, 10, 191-200.

Kuhn, R. A. (1950). Functional capacity of the isolated human spinal cord. Brain, 73, 1-9.

Lue, T. F., Zeineh, S. J., Schmidt, R. A. and Tanagho, E. A. (1984). Neuroanatomy of penile erection: its relevance to iatrogenic impotence. Journal of Urology, 131,273-280.

Miiller, L. R. (1906). fiber die Exstirpation der unteren Halfte des Ruckenmarks und deren Folgeerscheinungen. Deursche Zeitschrgt fur Nervenheilkunde, 30,413-425.

Walsh, P. C. and Donker, P. J. (1982). Impotence following radical prostatectomy: insight into etiology and prevention. Journal of Urology, 128,492-497.

The Authors D. A. Diamond, MD, Herbert Johnston Research Fellow,

A. M. K. Rickwood, FRCS, Urological Surgeon, Alder Hey

D. G. Thomas, Consultant Urologist, Spinal Injuries Unit,

Alder Hey Children’s Hospital.

Children’s Hospital.

Lodge Moor Hospital, Sheffield.

Requests for reprints to: A. M. K. Rickwood, Urological Department, Alder Hey Children’s Hospital, Eaton Road, Liverpool L12 2AP.