Male fertility and sexual function after spinal cord injury

Consequences of spinal cord injury on the sympathetic nervous system

Spinal cord injury (SCI) damages multiple structures at the lesion site, including ascending, descending, and propriospinal axons; interrupting the conduction of information up and down the spinal cord. Additionally, axons associated with the autonomic nervous system that control involuntary physiological functions course through the spinal cord. Moreover, sympathetic, and parasympathetic preganglionic neurons reside in the spinal cord. Thus, depending on the level of an SCI, autonomic function can be greatly impacted by the trauma resulting in dysfunction of various organs. For example, SCI can lead to dysregulation of a variety of organs, such as the pineal gland, the heart and vasculature, lungs, spleen, kidneys, and bladder. Indeed, it is becoming more apparent that many disorders that negatively affect quality-of-life for SCI individuals have a basis in dysregulation of the sympathetic nervous system. Here, we will review how SCI impacts the sympathetic nervous system and how that negatively impacts target organs that receive sympathetic innervation. A deeper understanding of this may offer potential therapeutic insight into how to improve health and quality-of-life for those living with SCI.

Sexuality, Intimacy, and Reproductive Health after Spinal Cord Injury

Spinal cord injury (SCI) is a life-altering event often accompanied by a host of anxiety-provoking questions and concerns in the minds of affected individuals. Questions regarding the ability to resume sexual activity, partner's satisfaction as well as the ability to have biological children are just a few of the unknowns facing patients following the devastating reality that is SCI. As a result of advances in SCI research over the last few decades, providers now have the knowledge and tools to address many of these concerns in an evidence-based and patient-centered approach. SCI can impair multiple components involved in sexual function, including libido, achieving and maintaining an erection, ejaculation, and orgasm. Many safe and effective fertility treatments are available to couples affected by SCI. Finally, learning to redefine one's self-image, reinforce confidence and self-esteem, and feel comfortable communicating are equally as important as understanding functionality in regaining quality of life after SCI. Thus, this review aims to highlight the current state of SCI research relating to sexual function, reproductive health, and the search for meaning.

Male Sexual Dysfunction and Infertility in Spinal Cord Injury Patients: State-of-the-Art and Future Perspectives

Spinal cord injury (SCI) is a relevant medical and social problem. According to the World Health Organization, the commonly estimated worldwide annual incidence of SCI is 40 to 80 cases per million population. After the SCI experience, most men present with sexual dysfunction (erectile dysfunction (ED) and ejaculatory dysfunction), fertility problems (such as impaired spermatogenesis, abnormalities in sperm viability, motility, and morphology), and systemic disorders such as genitourinary infection and endocrine imbalances. The best options available for managing the ejaculatory disorders in patients suffering from SCI are penile vibratory stimulation (PVS) and electroejaculation (EEJ). Furthermore, the treatment of ED in SCI patients consists of medical therapies including phosphodiesterase 5 inhibitors (PDE5i), intracavernosal injections (ICI), vacuum erection devices (VEDs), and surgical as penile prosthesis (PP). This review provides a snapshot of the current evidence for the mechanisms of sexual dysfunction and infertility in SCI patients, discusses the best management strategies for these conditions, and offers our perspective on the direction of future research.

From disability to fatherhood: Journey of serving soldiers with spinal cord injury

Background

Apart from neurological consequences, most distressing sequels of spinal cord injury (SCI) in men are erectile dysfunction, ejaculatory dysfunction and abnormal semen quality. Of these, ejaculatory dysfunction and poor semen parameters pose the biggest challenge to their biological fatherhood. Penile vibratory stimulation (PVS) and electroejaculation are first-line modalities for anejaculation, and surgical sperm retrieval (SSR) is adopted when other treatments fail. Sperms obtained using these techniques can be used for various fertility treatments for couples with spinal cord injured men. The aim of the study was to study the effectiveness of various modalities of sperm retrieval for assisted reproductive treatment in men with SCI.

Methods

It was a prospective observational study, wherein partners of 12 men with SCI presenting for subfertility underwent assisted reproduction after retrieving sperms via various modalities. The primary outcome was to assess efficacy of PVS in obtaining sperms and of SSR if PVS failed. The secondary outcome was to assess the pregnancy rate in their partners.

Results

PVS was successful in obtaining ejaculate in 7 of 12 men, and SSR was fruitful in 4 of 5 men. In vitro fertilization cycle for men who underwent PVS resulted in a pregnancy rate of 57.14% and 75% in couples for men who underwent SSR with an overall pregnancy rate of 58.33%.

Conclusion

With new cases of SCI occurring primarily in young men at the peak of their reproductive health, it is imperative that medical professionals involved with reproductive health should be aware of the various modalities to help them achieve biological paternity.

Spinal Cord Injury Causes Reduction of Galanin and Gastrin Releasing Peptide mRNA Expression in the Spinal Ejaculation Generator of Male Rats

Spinal cord injury (SCI) in men is commonly associated with sexual dysfunction, including anejaculation, and chronic mid-thoracic contusion injury in male rats also impairs ejaculatory reflexes. Ejaculation is controlled by a spinal ejaculation generator consisting of a population of lumbar spinothalamic (LSt) neurons that control ejaculation through release of four neuropeptides including galanin and gastrin releasing peptide (GRP) onto lumbar and sacral autonomic and motor nuclei. It was recently demonstrated that spinal contusion injury in male rats caused reduction of GRP-immunoreactivity, but not galanin-immunoreactivity in LSt cells, indicative of reduced GRP peptide levels, but inconclusive results for galanin. The current study further tests the hypothesis that contusion injury causes a disruption of GRP and galanin mRNA in LSt cells. Male rats received mid-thoracic contusion injury and galanin and GRP mRNA were visualized 8 weeks later in the lumbar spinal cord using fluorescent in situ hybridization. Spinal cord injury significantly reduced GRP and galanin mRNA in LSt cells. Galanin expression was higher in LSt cells compared to GRP. However, expression of the two transcripts were positively correlated in LSt cells in both sham and SCI animals, suggesting that expression for the two neuropeptides may be co-regulated. Immunofluorescent visualization of galanin and GRP peptides demonstrated a significant reduction in GRP-immunoreactivity, but not galanin in LSt cells, confirming the previous observations. In conclusion, SCI reduced GRP and galanin expression in LSt cells with an apparent greater impact on GRP peptide levels. GRP and galanin are both essential for triggering ejaculation and thus such reduction may contribute to ejaculatory dysfunction following SCI in rats.

Kinematic analysis of penile reflexes in a rat model of spinal cord injury

The ex-copula penile dorsiflexion reflex (PDFR) is an established measure of sexual dysfunction in male rat models of spinal cord injury. Although the PDFR after complete spinal transection is well described, information regarding the more clinically relevant incomplete spinal contusion injury model is limited. This study examined, using two-dimensional (2D) kinematic analysis, the relationship between the PDFR and degree of white matter sparing (WMS). Male Wistar rats received a T9 contusion with varying degrees of impactor forces. Weekly kinematic recordings of the PDFR were made 3–8 weeks postinjury. Sexual reflex components examined included maximum angle of penile dorsiflexion, total penile event duration, and penile ascent speed. Post hoc comparison between animals grouped based upon injury severity (moderate–severe: 13.33%–17.15% WMS vs moderate: 20.85%–33.50% WMS) indicated PDFR effects. Specifically, the numbers of animals with more moderate contusions having data points above the median in both maximum angle of penile dorsiflexion and penile ascent speed were significantly lower than animals with more severe injuries. Total penile event duration was also affected but only at more chronic time points (6–8 weeks). Thus, 2D kinematic analysis of the PDFR allows for more consistent and quantifiable analysis of the subtle differences that can occur between injury severity groups in the rat contusion model.

Altered sexual function after central neurological system trauma is reflective of region of injury; brain vs spinal cord

OBJECTIVE

To compare and contrast the contributory effects of traumatic brain injury (TBI) and spinal cord injury (SCI) on sexual function and social relationship opportunities, hypothesizing that patterns of change in sexual function would follow etiology.

DESIGN

Cross-sectional, case-matched survey of community living individuals with TBI, SCI or both (termed dual diagnosis).

PARTICIPANTS

Consecutive sample of participants with TBI (n = 25), SCI (n = 24) and dual diagnosis (n = 28), an average 3.6 years post-rehabilitation discharge.

METHODS

Participants were interviewed using a modified version of the 'Sexuality after Spinal Injury Questionnaire.'

RESULTS

Almost all respondents (97%) perceived adverse post-injury change in their experience of neurosexual function and/or social relationships. Physiological aspects of sexual function (e.g., erection, orgasm) were most affected by SCI whereas social relationships appeared more affected by TBI. People with dual diagnoses exhibited a combination of features. Participants with SCI (with or without TBI) were significantly more likely to have their concerns about sexual function discussed during rehabilitation than the TBI group.

CONCLUSION

TBI and SCI produce predictable impacts upon sexual function following injury, the impact of which were less frequently addressed during inpatient rehabilitation for those with TBI.

Chronic Spinal Cord Injury Reduces Gastrin-Releasing Peptide in the Spinal Ejaculation Generator in Male Rats

Spinal cord injury (SCI) causes sexual dysfunction, including anejaculation in men. Likewise, chronic mid-thoracic contusion injury impairs ejaculatory reflexes in male rats. Ejaculation is controlled by a spinal ejaculation generator (SEG) comprised of a population of lumbar spinothalamic (LSt) neurons. LSt neurons co-express four neuropeptides, including gastrin-releasing peptide (GRP) and galanin and control ejaculation via release of these peptides in lumbar and sacral autonomic and motor nuclei. Here, we tested the hypothesis that contusion injury causes a disruption of the neuropeptides that are expressed in LSt cell bodies and axon terminals, thereby causing ejaculatory dysfunction. Male Sprague Dawley rats received contusion or sham surgery at spinal levels T6-7. Five to six weeks later, animals were perfused and spinal cords were immunoprocessed for galanin and GRP. Results showed that numbers of cells immunoreactive for galanin were not altered by SCI, suggesting that LSt cells are not ablated by SCI. In contrast, GRP immunoreactivity was decreased in LSt cells following SCI, evidenced by fewer GRP and galanin/GRP dual labeled cells. However, SCI did not affect efferent connections of LSt, cells as axon terminals containing galanin or GRP in contact with autonomic cells were not reduced following SCI. Finally, no changes in testosterone plasma levels or androgen receptor expression were noted after SCI. In conclusion, chronic contusion injury decreased immunoreactivity for GRP in LSt cell soma, but did not affect LSt neurons per se or LSt connections within the SEG. Since GRP is essential for triggering ejaculation, such loss may contribute to ejaculatory dysfunction following SCI.

Activity-Based Training Alters Penile Reflex Responses in a Rat Model of Spinal Cord Injury

INTRODUCTION

Multisystem functional gains have been reported in males with spinal cord injury (SCI) after undergoing activity-based training (ABT), including increases in scoring of sexual function and reports of improved erectile function.

AIM

This study aims to examine the effect of daily 60-minute locomotor training and exercise in general on sexual function in a rat SCI contusion model.

METHODS

Male Wistar rats received a T9 contusion SCI. Animals were randomized into 4 groups: a quadrupedal stepping group (SCI + QT), a forelimb-only exercise group (SCI + FT), a non-trained harnessed group (SCI + NT), and a home cage non-trained group (SCI + HC). The 2 non-trained groups were combined (SCI) post hoc. Daily training sessions were 60 minutes in duration for 8 weeks. Urine samples were collected during bi-weekly 24-hour metabolic cage behavioral testing. Latency, numbers of penile dorsiflexion, and glans cupping were recorded during bi-weekly penile dorsiflexion reflex (PDFR) testing. Terminal electromyography (EMG) recordings of the bulbospongiosus muscle (BSM) were recorded in response to stimulation of the dorsal nerve of the penis (DNP).

OUTCOMES

ABT after SCI had a significant effect on PDFR, as well as BSM EMG latency and burst duration.

RESULTS

SCI causes a significant decrease in the latency to onset of PDFR. After 8 weeks of ABT, SCI + QT animals had a significantly increased latency relative to the post-SCI baseline. BSM EMG response to DNP stimulation had a significantly decreased latency and increase in average and maximum amplitude in SCI + QT animals. SCI animals had a significantly longer burst duration than trained animals. Time between PDFR events, penile dorsiflexion, glans cupping, and urine testosterone were not affected by ABT.

CLINICAL IMPLICATIONS

ABT has a positive influence on sexual function and provides a potential therapy to enhance the efficacy of current sexual dysfunction therapies in the male SCI population.

STRENGTHS AND LIMITATIONS

Several significant small improvements in sexual function were found in a clinically relevant rat model of SCI using a readily available rehabilitative therapy. The limited findings could reflect insensitivity of the PDFR as a measure of erectile function.

CONCLUSIONS

These results indicate that task-specific stepping and/or loading provide sensory input to the spinal cord impacting the neural circuitry responsible for sexual function. Steadman CJ, Hoey RF, Montgomery LR, et al. Activity-Based Training Alters Penile Reflex Responses in a Rat Model of Spinal Cord Injury. J Sex Med 2019; 16:1143-1154.

Oral probenecid improves sperm motility in men with spinal cord injury

STUDY DESIGN

Prospective cohort study (twenty men with spinal cord injury [SCI]).

OBJECTIVE

Determine if administration of oral probenecid results in improved sperm motility in men with SCI.

SETTING

Major university medical center.

METHODS

Twenty men with SCI were administered probenecid for 4 weeks (250 mg twice a day for 1 week, followed by 500 mg twice a day for 3 weeks). Semen quality was assessed at three time points: pre-treatment, post-treatment (immediately after the 4-week treatment), and follow-up (4 weeks after the last pill was ingested).

RESULT(S)

Probenecid was well-tolerated by all subjects. Sperm motility improved in each subject after 4 weeks of oral probenecid. The mean percent of sperm with progressive motility increased from 19% to 26% (P < 0.05). A more striking increase was seen in the mean percent of sperm with rapid linear motility, from 5% to 17%, (P <0.001). This improvement continued into the four week follow up period. Similar improvements were seen in the total motile sperm count (15 million, 28 million, and 27 million at pre-treatment, post-treatment, and follow-up, respectively). Sperm concentration was not significantly different at pre-treatment, post-treatment, and follow-up, (52 million, 53 million and 53 million, respectively).

CONCLUSION

This study showed that administration of an oral agent (probenecid) known to interfere with the pannexin-1 cellular membrane channel, can improve sperm motility in men with spinal cord injury. It is the first study to report improved sperm motility after oral medication in men with SCI.

Lipid Peroxidation and Its Role in the Expression of NLRP1a and NLRP3 Genes in Testicular Tissue of Male Rats: a Model of Spinal Cord Injury

Background:

The majority of male patients with spinal cord injury (SCI) suffer from infertility. Nucleotide-binding oligomerization domain-like receptors NOD-like receptors (NLRs) are a kind of receptors that corporate in the inflammasome complex. Recent studies have introduced the inflammasome as the responsible agent for secreting cytokines in semen. Reactive oxygen species (ROS) is one of the elements that trigger inflammasome activation. Genital infections in SCI can lead to ROS generation. We investigated the relation between lipid peroxidation and inflammasome complex activity in testicular tissue of SCI rats.

Methods:

Adult male rats (n=20), weighting 200-250 g, were included and divided into four groups: three experimental groups, including SCI1, SCI3, and SCI7, i.e. the rats were subjected to SCI procedure and sacrificed after one, three, and seven days, respectively and a control group. We performed a moderate, midline spinal contusion injury at thoracic level 10. The animals were anesthetized, and testes were collected for measurement of gene expression by real-time PCR. Caudal parts of epididymis were collected for malondialdehyde (MDA) measurement.

Results:

No NLRP1a mRNA overexpression was seen in the testes of control and SCI groups. After seven days from SCI surgery, NLRP3 mRNA expression was significantly increased in SCI7 animals (p ≤ 0.05). There was a significant difference in MDA level in SCI7 versus control group, as well as SCI1 and SCI3 animals (p ≤ 0.05).

Conclusion:

NLRP3 overexpression occurs due to the increased ROS production in testis tissue of SCI rats

Testosterone Reduces Spinal Cord Injury-Induced Effects on Male Reproduction by Preventing CADM1 Defect

Objective

This study evaluated the effects of exogenous testosterone molecule-1 (CADM1) pathological defect during early and chronic periods of spinal cord injury (SCI).

Materials and Methods

In this experimental study, testosterone was administered immediately or after one week of SCI induction. Along with quantification of CADM1 gene expression and its immunoreactivity, we evaluated sperm parameters and serum testosterone level post-SCI.

Results

Different grades of abnormalities in sperm parameters and testis architecture were observed along with significant reductions in the level of CADM1 expression and its immunoreactivity in the seminiferous tubules of both acute and chronic SCI groups. Exogenous testosterone, by compensating the serum testosterone level. reduced the percentage of apoptotic and both short head and abnormal sperm froms in the caudal epididymis. Importantly, the beneficial effects of immediate administration of testosterone were prominent. Increases in the level of CADM1 transcription and its immunoreactivity in the testis of SCI mice treated with testosterone were accompanied by improvement of sperm motility as well as testicular Johnsen’s and Miller’s criteria.

Conclusion

Since immediate testosterone treatment improved the immunoreactivity and transcription level of CADM1, the observed beneficial effect of exogenouse testosterone can be attributed to its effect on CADM1 dynamics.

Improving Sperm Viability After Spinal Cord Injury Using Hyperbaric Therapy

BACKGROUND

Infertility is one of many complications of spinal cord injury (SCI) in male patients, who are often at the peak of their reproductive life. This study evaluated effects of hyperbaric therapy (HT) on quality of sperm of rats with SCI and correlated the findings with histologic analysis of the testicles.

METHODS

This experimental study comprised 18 rats that were submitted to SCI with a MASCIS Impactor and randomly allocated to either a HT or a control group. Testicular biopsies were performed on the first and 28th day of the study; 4 parameters were evaluated: concentration of sperm per mL, number of round cells per field, number of inflammatory cells per field (peroxidase [Endtz] test), and sperm viability (hypo-osmotic swelling test).

RESULTS

There was no difference in sperm concentration between the HT group (P = 0.41) and control group (P = 0.74) during 28 days. From day 1 to day 28, sperm viability decreased twice as much in the control group (P = 0.001) compared with the HT group (P = 0.017). There was no difference between the groups in mean sperm concentration and number of round and inflammatory cells. On the first day, there was no difference in sperm viability between groups. There was a significantly higher (P = 0.001) percentage of viable sperm in the HT group (86.8 ± 5.6) compared with the control group (48.8 ± 21.8) on day 28.

CONCLUSIONS

SCI increased the number of round and inflammatory cells and diminished sperm viability in both groups. HT promoted greater sperm viability in rats with SCI.

A sexually dimorphic peptidergic system in the lower spinal cord controlling penile function in non-human primates

STUDY DESIGN

Experimental animal study.

OBJECTIVES

Although a population of gastrin-releasing peptide (GRP) neurons in the lumbar spinal cord has an important role in erection and ejaculation in rats, little information exists on this GRP system in primates. To identify the male-specific GRP system in the primate spinal cord, we studied the lumbosacral cord in macaque monkeys as a non-human primate model.

SETTING

University laboratory in Japan.

METHODS

To determine the gene sequence of GRP precursors, the rhesus macaque monkey genomic sequence data were searched, followed by phylogenetic analysis. Subsequently, immunocytochemical analysis for GRP was performed in the monkey spinal cord.

RESULTS

We have used bioinformatics to identify the ortholog gene for GRP precursor in macaque monkeys. Phylogenetic analysis suggested that primate prepro-GRP is separated from that of other mammalian species and clustered to an independent branch as primates. Immunocytochemistry for GRP further demonstrated that male-dominant sexual dimorphism was found in the spinal GRP system in monkeys as in rodents.

CONCLUSION

We have demonstrated in macaque monkeys that the GRP system in the lower spinal cord shows male-specific dimorphism and may have an important role in penile functions not only in rodents but also in primates.

SPONSORSHIP

Tissues of Nihonzaru (Japanese macaque monkeys) were provided in part by National Institutes of Natural Sciences (NINS) through the National Bio-Resource Project (NBRP) of the MEXT, Japan. This work was supported in part by KAKENHI from the Japan Society for the Promotion of Science (JSPS) (to KT; 15KK0343, 15J40220 and HS; 15K15202, 15KK0257, 15H05724).

Advances in the management of infertility in men with spinal cord injury

Couples with a spinal cord injured male partner require assisted ejaculation techniques to collect semen that can then be further used in various assisted reproductive technology methods to achieve a pregnancy. The majority of men sustaining a spinal cord injury regardless of the cause or the level of injury cannot ejaculate during sexual intercourse. Only a small minority can ejaculate by masturbation. Penile vibratory stimulation and electroejaculation are the two most common methods used to retrieve sperm. Other techniques such as prostatic massage and the adjunct application of other medications can be used, but the results are inconsistent. Surgical sperm retrieval should be considered as a last resort if all other methods fail. Special attention must be paid to patients with T6 and rostral levels of injury due to the risk of autonomic dysreflexia resulting from stimulation below the level of injury. Bladder preparation should be performed before stimulation if retrograde ejaculation is anticipated. Erectile dysfunction is ubiquitous in the spinal cord injured population but is usually easily managed and does not pose a barrier to semen retrieval in these men. Semen analysis parameters of men with spinal cord injury are unique for this population regardless of the method of retrieval, generally presenting as normal sperm concentration but abnormally low sperm motility and viability. When sperm retrieval is desired in this population, emphasis should be placed on initially trying the simple methods of penile vibratory stimulation or electroejaculation before resorting to more advanced and invasive surgical procedures.

Cardiovascular Responses to Sexual Activity in Able-Bodied Individuals and Those Living with Spinal Cord Injury

Sexuality is an integral part of the human experience and persists in health and disability. The cardiovascular system is crucial to sexual function and can be affected profoundly by spinal cord injury (SCI). The effects of sexual activity on the cardiovascular system in SCI have not been summarized and compared with sexual activity in able-bodied individuals. A keyword search of Embase, PubMed, and Medline was conducted. From 471 retrieved studies for able-bodied individuals, 11 were included that met the strict criteria of medically uncomplicated participants. In the SCI literature, 117 studies were screened, with 18 meeting criteria. In able-bodied persons, sexual activity resulted in modest increases in systolic blood pressure peaking at orgasm (males of 163 mm Hg and females of 142 mm Hg) and returning to baseline shortly afterward. In persons with SCI, results varied from minimal changes to significant elevations in systolic blood pressure because of episodes of autonomic dysreflexia, especially in those with high thoracic and cervical lesions. Peak systolic blood pressure in these individuals was measured to be as high as 325 mm Hg. In the SCI population, more intense stimuli (including penile vibrostimulation and electroejaculation) tended to result in a greater increase in systolic blood pressure compared with self-stimulation. Studies that used continuous versus intermittent monitoring were more likely to report greater changes in systolic blood pressure. In able-bodied persons, sexual activity results in modest increases in blood pressure. In those with SCI, intense stimulation and higher injury levels result in a higher likelihood of autonomic dysreflexia and elevated blood pressure. Because of rapid changes in blood pressure, continuous monitoring is more advantageous than intermittent measurement, because the latter may miss peak values.

Male fertility following spinal cord injury: an update

Spinal cord injury (SCI) occurs most often in young men at the peak of their reproductive health. The majority of men with SCI cannot father children naturally. Three major complications contribute to infertility in men with SCI: erectile dysfunction, ejaculatory dysfunction, and abnormal semen quality. Erectile dysfunction can be managed by regimens available to the general population, including oral administration of phosphodiesterase-5 (PDE-5) inhibitors, intracavernosal injections, vacuum devices, and penile prostheses. Semen may be obtained from anejaculatory men with SCI via the medically assisted ejaculation methods of penile vibratory stimulation (PVS) or electroejaculation (EEJ). Sperm retrieval is also possible via prostate massage or surgical sperm retrieval. Most men with SCI have abnormal semen quality characterized by normal sperm concentrations but abnormally low sperm motility and viability. Accessory gland dysfunction has been proposed as the cause of these abnormalities. Leukocytospermia is evident in most SCI patients. Additionally, elevated concentrations of pro-inflammatory cytokines and elevated concentrations of inflammasome components are found in their semen. Neutralization of these constituents has resulted in improved sperm motility. There is a recent and alarming trend in the management of infertility in couples with SCI male partners. Although many men with SCI have sufficient motile sperm in their ejaculates for attempting intrauterine insemination (IUI) or even intravaginal insemination, surgical sperm retrieval is often introduced as the first and only sperm retrieval method for these couples. Surgical sperm retrieval commits the couple to the most advanced, expensive, and invasive method of assisted conception: in vitro fertilization with intracytoplasmic sperm injection (IVF/ICSI). Couples should be informed of all options, including semen retrieval by PVS or EEJ. Intravaginal insemination or IUI should be considered when indicated.

Safety and efficacy of a new device for inducing ejaculation in men with spinal cord injuries

STUDY DESIGN

Prospective case series.

OBJECTIVES

Male infertility is a common sequela of spinal cord injury (SCI). Fatherhood is a goal in this group of young patients; however, most are anejaculatory. Penile vibratory stimulation is recommended as the first line of treatment for this condition. Our study evaluated the safety and efficacy of a new device designed to induce ejaculation in these patients.

SETTING

The Miami Project to Cure Paralysis, Miami, FL, USA.

METHODS

The Viberect-X3 (Reflexonic, Frederick, MD, USA) was applied to 30 consecutive anejaculatory men with SCI whose level of injury was T10 and rostral.

RESULTS

The ejaculatory success was 77% (23/30). No adverse events occurred, and there were no malfunctions of the device.

CONCLUSION

In this first report 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. Recommendation of the Viberect-X3 versus other devices intended for this purpose should not be made until randomized controlled trials are performed.

The Gastrin-Releasing Peptide Receptor (GRPR) in the Spinal Cord as a Novel Pharmacological Target

Gastrin-releasing peptide (GRP) is a mammalian neuropeptide that acts through the G protein-coupled receptor, GRP receptor (GRPR). Increasing evidence indicates that GRPR-mediated signaling in the central nervous system plays an important role in many physiological processes in mammals. Additionally, we have recently reported that the GRP system within the lumbosacral spinal cord not only controls erection but also triggers ejaculation in male rats. This system of GRP neurons is sexually dimorphic, being prominent in male rats but vestigial or absent in females. It is suggested that the sexually dimorphic GRP/GRPR system in the lumbosacral spinal cord plays a critical role in the regulation of male sexual function. In parallel, it has been reported that the somatosensory GRP/GRPR system in the spinal cord contributes to the regulation of itch specific transmission independently of the pain transmission. Interestingly, these two distinct functions in the same spinal region are both regulated by the neuropeptide, GRP. In this report, we review findings on recently identified GRP/GRPR systems in the spinal cord. These GRP/GRPR systems in the spinal cord provide new insights into pharmacological treatments for psychogenic erectile dysfunction as well as for chronic pruritus.

Neutralization of ASC improves sperm motility in men with spinal cord injury

STUDY QUESTION

Does neutralization of apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC) improve sperm motility in men with spinal cord injury (SCI)?

SUMMARY ANSWER

Neutralization of ASC improves sperm motility in men with SCI.

WHAT IS KNOWN ALREADY

Semen of men with SCI contains normal sperm concentrations but abnormally low sperm motility. Inflammatory cytokines, activated via the inflammasome complex, are contributory. A key component of the inflammasome is ASC.

STUDY DESIGN, SIZE, DURATION

This prospective study included semen samples collected from 32 men with SCI.

PARTICIPANTS/MATERIALS, SETTING, METHODS

At a major university medical center, untreated semen was compared with semen treated with anti-ASC polyclonal antibody. Semen treated with IgG was used as a control.

MAIN RESULTS AND THE ROLE OF CHANCE

Addition of anti-ASC polyclonal antibody to semen significantly increased mean sperm motility from 11.5% (95% CI, 6.3-16.7) to 18.3% (95% CI, 11.8-24.8). Improvements were most pronounced in the subgroup whose starting motility ranged between 6 and 40%. In this subgroup, the mean sperm motility improved from 13.3% (95% CI, 9.3-17.3) to 23.9% (95% CI, 14.7-23.0). Sperm motility did not improve after treatment with IgG.

LIMITATIONS, REASONS FOR CAUTION

This study is limited by the small sample size as this is a rare population.

WIDER IMPLICATIONS OF THE FINDINGS

Blockade of the inflammasome via treatment with anti-ASC improved sperm motility in men with SCI. In doing so, this treatment significantly increased their total motile sperm count. This is the first study to demonstrate that interference with the inflammasome improves sperm motility in men with SCI. This treatment has potential as a therapeutic intervention.

STUDY FUNDING/COMPETING INTERESTS

This study was funded by the Craig H. Neilsen Foundation, Grant # 224598, the University of Miami Miller School of Medicine and the Miami Project to Cure Paralysis, Miami, FL, USA. R.W.K. and J.P.d.R.V. hold a patent for the treatment of inflammation after central nervous system injury using antibodies against inflammasome proteins. The other authors have no conflicts of interest to declare.

Sexually dimorphic nuclei in the spinal cord control male sexual functions

Lower spinal cord injuries frequently cause sexual dysfunction in men, including erectile dysfunction and an ejaculation disorder. This indicates that the important neural centers for male sexual function are located within the lower spinal cord. It is interesting that the lumbar spinal segments contain several neural circuits, showing a clear sexually dimorphism that, in association with neural circuits of the thoracic and sacral spinal cord, are critical in expressing penile reflexes during sexual behavior. To date, many sex differences in the spinal cord have been discovered. Interestingly, most of these are male dominant. Substantial evidence of sexually dimorphic neural circuits in the spinal cord have been reported in many animal models, but major issues remain unknown. For example, it is not known how the different circuits cooperatively function during male sexual behavior. In this review, therefore, the anatomical and functional significance of the sexually dimorphic nuclei in the spinal cord corresponding to the expression of male sexual behavior is discussed.

Outcomes with intracytoplasmic sperm injection of cryopreserved sperm from men with spinal cord injury

BACKGROUND

Erectile dysfunction, ejaculatory dysfunction and poor semen quality are the main causes of infertility in men with spinal cord injury (SCI). Different sperm retrieval techniques such as penile vibratory stimulation (PVS), electro-ejaculation (EEJ) or surgical sperm retrieval (SSR) associated or not with sperm cryopreservation can be offered to these patients to preserve their fertility. If fatherhood cannot be achieved naturally, assisted reproductive techniques can be offered to these patients using either fresh or frozen/thawed sperm. The aim of the study was to report in SCI patients from Dijon (Burgundy) and in the literature, intracytoplasmic sperm injection (ICSI) outcomes using frozen sperm obtained either by antegrade ejaculation (PVS or sexual intercourse) or by SSR.

METHODS

A retrospective analysis was performed in Dijon, Burgundy over a 17 year period (1995-2011) on a cohort of 19 SCI men (6 quadriplegics and 13 paraplegics, mean age: 25.2 ± 5.6 years) who underwent a sperm cryopreservation followed or not by intracytoplasmic sperm injection (ICSI). Patients were divided into two groups according to the sperm retrieval method used (antegrade ejaculation group (n=10): penile vibratory stimulation (PVS) for 9 patients and sexual intercourse for 1 patient and surgical sperm retrieval (SSR) group: n=9). The sperm parameters in both groups were analyzed. Pregnancy outcomes in the 8 couples who underwent ICSI were evaluated.

RESULTS

The fertilization rates were 57 and 55%, the embryo's cleavage rates were 90 and 93% in the antegrade ejaculation and SSR groups respectively. Among the 8 couples who underwent ICSI, 5 couples achieved pregnancy. The pregnancy rates per couple were 50% and 75% in the antegrade and SSR groups respectively.

CONCLUSIONS

Although some studies don't recommend freezing sperm in SCI patients, the pregnancy rates presented in this study are encouraging and warrant the use of frozen/thawed sperm in very specific situations.

Ejaculatory dysfunction

Ejaculatory dysfunction may occur after many different disorders ranging from traumatic spinal cord injury to diabetes mellitus. With an understanding of the many facets and nuances of the ejaculatory apparatus, both anatomic and neurologic, the well-versed clinician can proceed along a safe, efficient, and appropriate treatment algorithm to help affected men and their partners achieve parenthood.

Sperm chromatin condensation, DNA integrity, and apoptosis in men with spinal cord injury

OBJECTIVES

To evaluate the effect of cord injury on (1) sperm parameters and (2) DNA chromatin status.

DESIGN

Case-control study.

SETTING

Data were collected from men referred to Research and Clinical Center for Infertility, Yazd, Iran.

PARTICIPANTS

Thirty infertile men with the presence of any level of spinal cord injury (SCI) were compared with 30 healthy donors with definite fertility and normal sperm parameters.

INTERVENTIONS

Not applicable.

OUTCOME MEASURES

Sperm chromatin integrity was assessed using aniline blue (AB), chromomycin A3 (CMA3), toluidine blue (TB), and acridine orange (AO) assays. The rate of apoptotic spermatozoa was evaluated with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) staining.

RESULTS

Sperm concentration, motility, and morphology in men with SCI were significantly decreased compared with control group (P < 0.05). In addition, with regard to cytochemical staining and TUNEL test, the rate of reacted spermatozoa was increased significantly in SCI group when compared with the controls (P < 0.05). The majority of AB, TB, AO, and CMA3-reacted spermatozoa were higher than the "cut-off" value in men with SCI, as were the number of apoptotic spermatozoa stained with TUNEL.

CONCLUSION

Results showed that SCI disturbs sperm parameters, nuclear maturity, and DNA integrity of spermatozoa. Therefore, the production of spermatozoa with less condensed chromatin and more apoptotic rate increases after cord injury and this may be one possible cause of infertility following SCI.

Infertility in men with spinal cord injury: research and treatment

Spinal cord injury (SCI) occurs most often to young men. Following SCI, most men are infertile due to a combination of erectile dysfunction, ejaculatory dysfunction and semen abnormalities. Erectile dysfunction may be treated by the same therapies that are used in the general population. Similarly, the same treatments that are effective to assist conception in couples with non-SCI male factor patients are effective in assisting conception in SCI male-factor patients. The most apparent differences in male-factor symptoms between SCI and non-SCI patients are the high occurrences of anejaculation and atypical semen profiles in men with SCI. Methods available to assist ejaculation in men with SCI include penile vibratory stimulation and EEJ. Use of surgical sperm retrieval as the first line of treatment for anejaculation in men with SCI is controversial. Most men with SCI have a unique semen profile characterized by normal sperm concentration, but abnormally low sperm motility. Toxic substances in the semen contribute to this problem. Despite impaired sperm parameters, pregnancy outcomes using sperm from men with SCI are similar to pregnancy outcomes using sperm from non-SCI men. Future studies should focus on improving natural ejaculation and improving semen quality in these men.

Treatment of infertility in men with spinal cord injury

Most men with spinal cord injury (SCI) are infertile. Erectile dysfunction, ejaculatory dysfunction and semen abnormalities contribute to the problem. Treatments for erectile dysfunction include phosphodiesterase type 5 inhibitors, intracavernous injections of alprostadil, penile prostheses, and vacuum constriction devices. In anejaculatory patients who wish to father children, semen retrieval is necessary. Penile vibratory stimulation is recommended as the first line of treatment. Patients who fail penile vibratory stimulation can be referred for electroejaculation. If this approach is not possible, prostate massage is an alternative. Surgical sperm retrieval should be considered as a last resort when other methods fail. Most men with SCI have a unique semen profile characterized by normal sperm count but abnormally low sperm motility. Scientific investigations indicate that accessory gland dysfunction and abnormal semen constituents contribute to the problem. Despite abnormalities, sperm from men with SCI can successfully induce pregnancy. In selected couples, the simple method of intravaginal insemination is a viable option. Another option is intrauterine insemination. The efficacy of intrauterine insemination increases as the total motile sperm count inseminated increases. In vitro fertilization and intracytoplasmic sperm injection are options in cases of extremely low total motile sperm count. Reproductive outcomes for SCI male factor infertility are similar to outcomes for general male factor infertility.

Neuroanatomy and neurophysiology related to sexual dysfunction in male neurogenic patients with lesions to the spinal cord or peripheral nerves

STUDY DESIGN

Review article.

OBJECTIVES

The neuroanatomy and physiology of psychogenic erection, cholinergic versus adrenergic innervation of emission and the predictability of outcome of vibration and electroejaculation require a review and synthesis.

SETTING

University Hospital Belgium.

METHODS

We reviewed the literature with PubMed 1973-2008.

RESULTS

Erection, emission and ejaculation are separate phenomena and have different innervations. It is important to realize, which are the afferents and efferents and where the motor neuron of the end organ is located. When interpreting a specific lesion it is important to understand if postsynaptic fibres are intact or not. Afferents of erection, emission and ejaculation are the pudendal nerve and descending pathways from the brain. Erection is cholinergic and NO-mediated. Emission starts cholinergically (as a secretion) and ends sympathetically (as a contraction). Ejaculation is mainly adrenergic and somatic. For vibratory-evoked ejaculation, the reflex arch must be complete; for electroejaculation, the postsynaptic neurons (paravertebral ganglia) must be intact.

CONCLUSION

Afferents of erection, emission and ejaculation are the pudendal nerve and descending pathways from the brain. Erection is cholinergic and NO-mediated. Emission starts cholinergically (as a secretion) and ends sympathetically (as a contraction). Ejaculation is mainly adrenergic and somatic. In neurogenic disease, a good knowledge of neuroanatomy and physiology makes understanding of sexual dysfunction possible and predictable. The minimal requirement for the success of penile vibration is a preserved reflex arch and the minimal requirement for the success of electroejaculation is the existence of intact post-ganglionic fibres.

Measurement of sexual functioning after spinal cord injury: preferred instruments

BACKGROUND/OBJECTIVE

To determine the utility of certain instruments to assess sexuality and fertility after SCI, an expert panel identified key areas to study and evaluated available instruments. These were rated according to certain predefined criteria.

METHODS

The authors divided sexual issues into male and female sexual function, male reproductive function, and female reproductive function. The instruments that have been used most frequently to measure these aspects of sexual function over the past 5 years were identified by expert consensus. Finally, these instruments were subjected to a critical review.

RESULTS

The Female Sexual Function Index (FSFI), measurement of vaginal pulse amplitude (VPA), the International Index of Erectile Function (IIEF), and the measurement of ejaculatory function and semen quality were considered appropriate measures to assess sexual responses and reproductive function after SCI. There were no measures identified to assess female reproductive function.

CONCLUSIONS

For clinical trials aiming to improve sexual function after SCI, the FSFI or the IIEF is currently preferred. Although VPA is an appropriate means to assess female sexual responses, it is only useful for laboratory studies and is too invasive for use in clinical trials. For assessment of male fertility potential, assessment of ejaculatory capacity and semen analysis are recommended.

Ten years of phosphodiesterase type 5 inhibitors in spinal cord injured patients

INTRODUCTION

The majority of men with spinal cord injury (SCI) require chronic treatment for erectile dysfunction (ED), but most of them, prior to taking phosphodiesterase type 5 (PDE5) inhibitors, stopped therapy due to side-effects or low compliance rate.

AIM

Analysis of literature on oral PDE5 inhibitors in individuals with SCI and ED in order to evaluate how much their release changed the management of ED in SCI subjects and what remains to be seen of their potential or limits.

MAIN OUTCOME MEASURES

Questionnaires on sexual function.

METHODS

18 internationally published clinical studies that enrolled SCI males treated with at least one of the PDE5 inhibitors were analyzed.

RESULTS

The small numbers of papers with large and diverse outcome measures did not consent a meta-analysis of treatment results. 705 used sildenafil, 305 vardenafil and 224 tadalafil. Median age was less than 40 years. Only 1 study excluded tetraplegic individuals. For measures of ED evaluated, 11 out of 13 studies reported a significant statistical improvement with PDE5 inhibitors versus placebo or erectile baseline (P < 0.01, or p < 0.005). The most frequent predicable factor for the therapeutic success of PDE5 inhibitors was upper motoneuron lesion. Statistical impact on ejaculation success rates was shown in at least one paper for all PDE5 inhibitors (p < 0.05). Overall, 15 patients, (7 using sildenafil), discontinued the therapies due to drawbacks. Only 1 sildenafil study reported a follow-up maximum of 24 months.

CONCLUSIONS

Literature suggests that all oral PDE5 inhibitors represent a safe and effective treatment option for ED caused by SCI. Further research is needed on head-to-head comparative trials and SCI patient preference for these drugs; their impact on ejaculation and orgasm function, their early use after SCI for increasing the recovery rate of a spontaneous erection, and their effectiveness and tolerability in the long-term are still to be investigated.

Safety of a novel treatment to improve sperm motility in men with spinal cord injury

Seminal plasma of men with spinal cord injury (SCI) contains high concentrations of cytokines. Neutralizing these target cytokines did not damage sperm DNA or sperm viability, indicating that this method may hold promise as a safe therapy for improving sperm motility in men with SCI.

Vardenafil improves ejaculation success rates and self-confidence in men with erectile dysfunction due to spinal cord injury

STUDY DESIGN

Multicenter, double-blind, placebo-controlled, parallel-group study.

OBJECTIVE

To assess the effect of the oral phosphodiesterase type-5 inhibitor, vardenafil, on ejaculation rates and self-confidence in men with spinal cord injury (SCI).

SUMMARY OF BACKGROUND DATA

Spinal command of male sexual functions is often seriously impaired by traumatic spinal cord injury (SCI). A high proportion of men with SCI cannot ejaculate during sexual intercourse. SCI-related ejaculatory disorders are often responsible for male infertility. Sexual dysfunction associated with SCI can also affect men's self-confidence.

METHODS

In this 12-week study, 418 men aged >or=18 years with erectile dysfunction >6 months resulting from a traumatic SCI were randomized to vardenafil (n = 207) or placebo (n = 211) 10 mg for 4 weeks, then maintained or titrated to 5 or 20 mg at weeks 4 and 8. Assessments included questions of the International Index of Erectile Function (IIEF) about ejaculation success and orgasmic perception; the Global Confidence Question; and quality-of-life scales to measure psychological well-being, self-esteem, depression, and mental health status.

RESULTS

Overall per patient ejaculation success rates were significantly greater with vardenafil than placebo over 12 weeks of treatment (19% vs. 10%; P < 0.001). At last observation carried forward, the IIEF "orgasmic function" score increased from 2.9 at baseline to 4.0 for vardenafil and from 3.0 at baseline to 3.4 for placebo. Sixteen percent of men receiving vardenafil and 8% receiving placebo felt orgasm "almost always" or "always" at weeks 8-12, compared with 4% and 6%, respectively, at baseline. Significant improvements in confidence scores were observed with vardenafil compared with placebo (P < 0.0001). There were no clinically significant differences between vardenafil and placebo in the quality-of-life measures at the study endpoint, but these had been in the normal range at baseline.

CONCLUSION

Vardenafil significantly improved ejaculation and self-confidence in men with erectile dysfunction due to SCI.