Which men with SB should be screened for ED? According to our SHIM survey data, 94% of sexually active adult men with SB had some degree of ED, with 50% of respondents having a score less than 11 (moderate to severe).
Furthermore, neither sexual activity nor degree of ED correlated with ambulation status (walking vs. wheelchair). This is an important finding, as a prior study found that those who are overtly handicapped, especially those who are wheelchair-dependent, are often presumed to be asexual (Urology. 1998;52:3-11).
Urologists and other health-care providers cannot make this broad assumption. Men with SB do indeed have decreased access to sexual encounters compared with normal healthy peers, but sexual desire remains intact. Studies have shown that 80%-100% of men with SB report normal sexual desires and fantasies and are actively interested in sexual activity (J Child Psychol Psychiatry. 1977;18:229-237, Hinyokika Kiyo. 1995; 41:985-989, and Dev Med Child Neurol. 1996;38:823-829). Discussion of ED should therefore be initiated by the urologist or primary-care provider treating males with SB.
As with erections, men with SB have variable ejaculation ability and orgasms, making issues of fertility and paternity of interest. Although the number of adult men with SB who are married and actively seeking to father children is low, paternity rates are reported to be between 56% and 73% (J Urol. 1997;157:1466-1468 and Dev Med Child Neurol Suppl. 1975;17:123-128). Paternity rates are higher in patients with lower lesions, and in the 1997 Journal of Urology series, seven of the eight patients who fathered a child had lesions at L5 or lower. It is unclear whether paternity rates reflect impotence, abnormal ejaculation, subnormal fertility potential, or a combination of the three.
As many as 75% of men with SB experience ejaculation, but it tends to be dripping and not necessarily associated with typical orgasm sensation. One fifth of men studied do not positively perceive ejaculation, which may be secondary to absent penile sensation (J Urol. 1997;157:1466-1468). Whether this aspect affects paternity by inability to deliver semen to the cervix is not known, but inability to ejaculate is seen in men with higher lesions. Infertility in terms of abnormal semen parameters in this population has not been reported.
A common question in adults with SB who are interested in having natural children focuses on neural tube defects (NTDs) in the offspring. The risk of NTD may indeed be higher in parents with SB compared with the general population. Older reports show a 3.7% incidence of NTD among parents with SB, whether the affected parent is male or female.
This is markedly higher than the 0.1% incidence seen in the general population but may be an overestimate, as these reports were published prior to the widespread implementation of prenatal folic acid. When parents have a child with an NTD, the risk of a second affected child increases to 2%-5%, illustrating potential genetic factors. The Duke Center for Human Genetics in Durham, N.C., is researching the hereditary basis of NTDs and has enrolled more than 1,200 families since 1993.
Until these studies increase our understanding of NTD prevention, recommendations should include regular prenatal care and counseling in addition to strict female adherence to daily folic acid in the month prior to conception and the first three months of pregnancy. The standard dose of folic acid is 0.4 mg/day, but many obstetricians advocate 4 mg/day in parents who have previously had a child with an NTD.
The adult population with SB is increasing faster than the literature addressing issues related to sexual maturity in these patients, as illustrated by the fact that in the past decade, fewer than 10 urologic publications have addressed the topics discussed here.
It seems evident, however, that most men with SB, regardless of severity of handicap, are interested in sexual activity and information, and discussions related to sexual health should be initiated by health-care providers without assumptions. ED is variable and dependent on the level of neurologic lesion, but conventional therapies, including PDE5 inhibitors, appear to be effective.
Infertility is essentially unstudied in this population, but paternity has been demonstrated and patients seeking to father children should be counseled about NTDs and preventive measures.
Dr. Bong is chief resident in the department of urology and Dr. Rovner is professor of urology at the Medical University of South Carolina in Charleston.