Based on published clinical research and medical practice
Ejaculation is a complex process requiring coordinated activity between the brain, spinal cord, and peripheral nerves around the penis. Understanding this mechanism is essential for accurate diagnosis and selecting the most appropriate treatment for premature ejaculation (PE).
Mechanisms of Ejaculation
1. Brain-mediated ejaculation
The brain acts as the central control center, integrating sensory and psychological stimuli—such as vision, sound, touch, emotions, and thoughts—before sending signals through the spinal cord.
- Marson L et al., Journal of Comparative Neurology, 1993: The medial preoptic area (MPOA) and paraventricular nucleus (PVN) of the hypothalamus play a key role in initiating ejaculation via descending neural pathways to the spinal cord.
- Examples: nocturnal emission, ejaculation triggered by erotic content or imagination, ejaculation during intense excitement or stress.
2. Spinal reflex ejaculation
The spinal cord, especially the spinal ejaculation generator at L3–L5, can directly trigger ejaculation through reflex arcs, even without brain input.
- Truitt WA & Coolen LM, Trends in Neurosciences, 2002: The lumbosacral spinal segment coordinates muscle contractions and semen expulsion.
- Examples:
- Spinal cord injury patients above L3 who still ejaculate upon stimulation
- Penile vibratory stimulation (PVS) — Brackett NL et al., Spinal Cord, 2007: PVS activates the dorsal nerve → pudendal nerve → spinal reflex center, leading to ejaculation even in SCI patients
- Electroejaculation — Szasz G et al., Fertility and Sterility, 1984: Transrectal electrical stimulation triggers the spinal reflex center for ejaculation
- Spinal cord injury patients above L3 who still ejaculate upon stimulation
3. Peripheral stimulation
Tactile stimulation of penile and perineal sensory receptors sends signals via the pudendal nerve to the spinal cord, and then to the brain or spinal reflex center.
- Giuliano F & Clement P, Progress in Neurobiology, 2005: The dorsal nerve of the penis contains mechanoreceptors sensitive to touch and pressure, transmitting via the pudendal nerve.
- Examples: penetrative sex, masturbation, use of stimulation devices.
Intravaginal Ejaculatory Latency Time (IELT)
- BJU International: Median ~5.4 minutes (range 0.55–44.1 min)
- Age 18–30: ~6.5 min
- Age >51: ~4.3 min (Journal of Sexual Medicine)
- PE patients: ~1.8 min vs normal group: ~7.3 min (Journal of Sexual Medicine)
- European Urology: 75.1% of PE cases had IELT ≤ 4 min, and 55.7% ≤ 2 min
Types of Premature Ejaculation
- Lifelong PE – Present from first sexual experience, IELT ≤ 1 min, often linked to genetic or neurophysiological factors.
- Acquired PE – Previously normal, now shorter IELT ≤ 3 min, due to medical conditions, hormonal changes, psychological factors, or injury/surgery effects.
Treatment Criteria
Treatment should be considered when:
- Latency time is inconsistent with partner’s satisfaction
- Ejaculation is uncontrollable, affecting self-confidence
- Causes distress or relationship issues
- Underlying medical issues are present
- Non-surgical measures fail
Treatment Approaches
Central level (Brain) – SSRIs, mindfulness, breathing control, distraction techniques
Spinal level – Tramadol, TENS, PVS
Peripheral level – Topical anesthetics, thicker condoms, surgical desensitization
Dorsal Nerve Neuroectomy
- Mechanism: Partial removal of the dorsal nerve to reduce sensory input, prolonging time to ejaculation
- Advantages: Permanent effect, no need for medication each time, suitable for cases unresponsive to other treatments
- Drawbacks: Reduced sensation, risk of numbness or scarring, potential erectile issues, must be performed by an experienced surgeon
Summary
Ejaculation is controlled by brain, spinal cord, and peripheral nerve interaction. Treatment must target the relevant level of dysfunction. Dorsal nerve neuroectomy is a last-line option for refractory cases and may improve quality of life when conservative measures fail.
