Combining Motor Imagery and Action Observation with Vibratory Stimulation Increases Corticomotor Excitability in Healthy Young Adults

Vibratory stimulation but also motor imagery and action observation can induce corticomotor modulation, as a bottom-up stimulus and top-down stimuli, respectively. However, it remains unknown whether the combination of motor imagery, action observation, and vibratory stimulation can effectively increase corticomotor excitability. This study aimed to investigate the effect of motor imagery and/or action observation, in the presence or absence of vibratory stimulation, on the corticomotor excitability of healthy young adults. Vibratory stimulation was provided to the palm of the right hand. Action observation consisted in viewing a movie of someone else’s finger flexion and extension movements. The imagery condition required the participants to imagine they were moving their fingers while viewing the movie and attempting to move their fingers in accordance with the movie. Eleven right-handed healthy young adults were asked to perform six conditions randomly: 1) vibratory stimulation, imagery, and action observation, 2) vibratory stimulation and action observation, 3) vibratory stimulation and viewing of a blank screen, 4) imagery and action observation, 5) action observation, and 6) viewing of a blank screen. Single-pulse transcranial magnetic stimulation was conducted to assess corticomotor excitability and the peak-to-peak amplitude of the motor evoked potentials. The results showed that vibratory stimulation increases corticospinal excitability. The findings further revealed that performing motor imagery while viewing finger movement is more effective at inducing an augmentation of corticomotor excitability compared to action observation alone. Thus, the combination of motor imagery, action observation, and vibratory stimulation can effectively augment corticomotor excitability.

Semen parameters in men with spinal cord injury： changes and aetiology

Aim： To assess the changes in semen parameters in men with spinal cord injury （SCI） and the possible causes of these changes. Methods： The study included 45 subjects with SCI. Semen retrieval was done by masturbation （2）, vigorous prostatic massage （n = 13）, penile vibratory stimulation （n = 13） or electroejaculation （n = 17）. Results： The semen of men with SCI showed normal volume （2.3 ± 1.9 mL） and sperm count （85.0 × 10^6 ± 83.8 × 10^6/mE） with decreased motility （11.6% ± 10.1%）, vitality （18.5 % ± 15.2%） and normal forms （17.5 ± 13.4%）, and pus cells has been increased （6.0 × 10^6 ± 8.2 × 10^6/mL）. Total （13.4 ± 9.9 vs. 7.1 ± 6.8） and progressive （4.4 ± 3.9 vs. 2.2 ± 2.1） motility were significantly higher in subjects with lower scrotal temperatures. There was no statistical significant difference between electroejaculation and penile vibratory stimulation groups as regards any of the semen parameters. Subjects＇ age, infrequent ejaculation, injury duration and hormonal profile showed no significant effect on semen parameters. Conclusion： The defining characteristics of the seminogram in men with SCI are normal volume and count with decreased sperm motility, vitality and normal forms, and the increased number of pus cells. The most acceptable cause of the deterioration of semen is elevated scrotal temperature.

Management of ejaculatory disorders in infertile men

Ejaculatory dysfunction is a highly prevalent clinical condition that may be classified along a continuum that ranges from premature ejaculation （PE）, through retarded or delayed ejaculation （DE）, to complete anejaculation （AE）. Retrograde ejaculation （RE） represents a distinct entity in which ejaculate is expelled either partially or completely into the bladder. While DE and PE are significant sources of sexual dissatisfaction among men and their partners, patients with these disorders retain normal fertility in most cases. Conversely, men with AE and RE are unable to deliver sperm into the female genital tract and are therefore rendered subfertile. Therefore, in reviewing ejaculatory disorders as they relate to fertility, this paper will primarily focus on the diagnosis and management of AE and RE. Physiology, diagnostic strategies, pharmacological treatments, and procedural interventions relevant to AE and RE are discussed.

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.