Ejaculation, the process of external semen expulsion, is primarily a sympathetic phenomenon (involving the spinal cord segment between T10-L2). Internally, there is a pathway for sperm to be transported from the testicles with accessory fluids before being expelled out the end of the penile urethra (antegrade ejaculation) (Krassioukov and Elliott, 2017). Ejaculatory disorders (most often the lack of both seminal emission and antegrade ejaculation called anejaculation) are highly prevalent (reported at over 90%) so fertility can be a major issue for men with SCI (Elliott, 2002). Ejaculation is most likely to occur naturally in men with incomplete conus or cauda equina lesions, and men with lesions higher than T6; ejaculation is least likely to occur naturally in men with complete supraconal lesions (Comarr, 1985; Ibrahim et al. 2016). Retrograde ejaculation can also occur, most often in men with sphincterotomy or who have a suprapubic catheter (Ibrahim et al. 2016).
Much of our existing knowledge of ejaculation and orgasmic sexual satisfaction is derived either from self-report surveys or indirectly reported in the fertility literature, thus further research is needed. Not surprisingly, there are no RCT studies in this area, with only one study performing laboratory evaluation of these altered responses in men with SCI (Sipski et al. 2006). Orgasm, in particular, is a phenomenon that is not well defined, either clinically or neurophysiologically, being generated via cerebral, body or genital sources of stimulation, and usually is self-described by participants only in terms of being either similar or different in comparison to their pre-injury experience. Sipski et al. (2006) report that the preservation of light touch and pinprick sensation in the T11-L2 dermatomes is helpful in predicting which people with SCI can achieve psychogenic arousal.
A study by Phelps et al. (1983) found 42% of 50 male veterans with SCI reported orgasm. Alexander et al. (1993) showed in their series that the majority of 38 men with SCI could not ejaculate, with the exception of those with an incomplete paraplegia of whom 75% could ejaculate in some fashion. Despite this, they reported that in the group with complete SCI lesions, 50% of the men with tetraplegia and 25% of those with paraplegia reported that they could have some sort of orgasm, and of those that could, 38% with tetraplegia and 67% with paraplegia reported it was not accompanied by ejaculation. For the men with incomplete SCI lesions, 66% of the men with tetraplegia said they could have orgasm (of which 50% said it was accompanied by ejaculation) and 75% of those with paraplegia reported they could have some kind of orgasm that was always accompanied by ejaculation. There was a significant correlation between the ability to have an orgasm and ejaculation, as was the ability to ejaculate and having an erection firm enough for penetration.
Similarly, a recent laboratory study of 45 men with SCI and 6 able-bodied controls (Sipski et al. 2006) demonstrated that 79% of the men with incomplete lesions and 28% of those with complete lesions achieved orgasm in the laboratory setting (historically, these men reported post-injury orgasmic ability to be 84% and 50%, respectively). Independent significant predictors of orgasm in the laboratory were completeness of injury and prior history of orgasm post-injury. Those men with lower motor neuron lesions affecting the sacral segments (n=4) had no historical or laboratory experience with orgasm. They also reported that although orgasm and ejaculation were likely to occur together, the presence of orgasm was not necessarily connected with presence of ejaculation.
Microsurgery of the sensory nerves to the penis is one promising treatment for improving senation and orgasm in men (Overgoor et al. 2013). A sensory substitution technology trained patients over 20 sessions to map tongue sensations to sensory perceptions of the genitalia (Borisoff et al. 2010) is one other possible therapeutic avenue for sexual rehabilitation.
One study (Soler et al. 2008) examined the effect of midodrone, an oral selective alpha-adrenoceptor agonist, which is mainly used as a treatment for orthostatic hypotension, on orgasm among 158 individuals with SCI who failed to ejaculate at home and when using penile vibratory stimulation. Soler et al. (2008) found that midodrine combined with penile vibratory stimulation produced orgasm in 59% of participants compared to 9% with vibratory stimulation alone, and orgasm was significantly related (84%) to the presence of either antegrade or retrograde ejaculation. Orgasm was experienced more among individuals with incomplete injuries (vs complete) and among individuals with upper motor lesions (vs lower motor lesions). It is important to note that the sympathomimetic effect results in a significant increase in both systolic and diastolic blood pressure, and caused several patients to develop intense autonomic dysreflexia that required medical attention. It is theorized that orgasmic sensations, with or without ejaculation, are related to somatic responses of vibrostimulation and perceived sensations of autonomic dysreflexia, and that orgasm appears to be a reflex partly under cerebral influence and could therefore be learned and practiced (Courtois et al. 2004; Elliott 2002). In research on the efficacy of the Viberect-X3 for treatment of anejaculation in men with SCI, we conclude that the device is safe and effective for inducing ejaculation in men with SCI.
There is level 4 evidence (Overgoor et al. 2013) that microsurgery of the sensory nerves to the penis may be one treatment for improving sensation and orgasm in men.
There is level 4 evidence (Borisoff et al. 2010) that sensory substitution training may be one therapeutic avenue for sexual rehabilitation.
There is level 4 evidence (Soler et al. 2008) that oral midrodrine may improve orgasm and ejaculation in men with SCI and level 4 evidence that PVS and midrodrine induces ejaculation in anejaculatory males with SCI.
There is level 1b evidence (Leduc et al. 2015) that oral midrodrine and PVS does not result in a better rate of antegrade ejaculation in men with traumatic SCI.
There is level 5 evidence (Courtois et al. 2014) that 53% of patients complained of premature ejaculation and 15% complained of spontaneous ejaculation.
Promising options (but with limited evidence) exist for improving the chance of reaching orgasm in men with SCI include microsurgery of the sensory nerves to the penis and sensory substitution training.
The use of oral midrodrine to encourage ejaculation may also improve chance of orgasm.