The effect of local anesthetic on the hypersensitive and nonsensitive areas of the penis is different in primary premature ejaculation: a pilot study.

Background: Penile hypersensitivity is not the whole penis, but rather only a part of the penis. Though local anesthetic can prolong intravaginal ejaculation latency time by reducing penile hypersensitivity, the effect on the hypersensitive and nonsensitive areas of penis is still unclear. Aim: The study aimed to explore whether the effect of local anesthetic on the hypersensitive and nonsensitive areas of the penis is different in premature ejaculation. Methods: Penile neurophysiological tests were performed on 290 patients with primary premature ejaculation. The sensory threshold, latency, and amplitude were recorded before and after the topical application of a local anesthetic (lidocaine cream) on the penis. Outcomes: Local anesthetics increased the sensory thresholds of hypersensitive and nonsensitive areas of the penis without difference but only prolonged the latency of the hypersensitive areas. Results: According to the neurophysiological results, 149 of 290 patients with primary premature ejaculation had normal penile sensitivity and 141 had penile hypersensitivity. While penile hypersensitivity does not necessarily mean that the whole penis is hypersensitive, and may be that only a part of the penis is hypersensitive, and we examined the following hypersensitivities: glans hypersensitivity only (14 cases), shaft hypersensitivity only (77 cases), and whole penis hypersensitivity (50 cases). Local anesthetics (lidocaine cream) increased the sensory thresholds of hypersensitive and nonsensitive areas of the penis without difference (P < .001) but only prolonged the latency of the hypersensitive areas (P < .001), and the latency of the nonsensitive areas was not different (P > .05). Clinical Implications: The present discovery implies that it is possible to improve ejaculation by applying local anesthetics externally to the hypersensitive areas of the penis to reduce the afferent local sensory signals, and improve intravaginal ejaculation latency time through accurately decreasing penile sensibility. Strengths & Limitations: This is the first large-sample study to explore the difference of local anesthetics' effects on the hypersensitive and nonsensitive areas of the penis by means of neurophysiological methods in premature ejaculation. Our study exclusively examines alterations in penile evoked potential following electrical stimulation, which may not entirely encompass shifts in penile receptivity during sexual activity. Conclusion: The effects of local anesthetics on the same penis varied with penile sensitivity, and can only prolong the latency of hypersensitive area of the penis. The effect of local anesthetic on the hypersensitive and nonsensitive areas of the penis is different in premature ejaculation.

The sensitivity difference between the glans penis and penile shaft in primary premature ejaculation.

The penis is a vital organ of perception that transmits perceived signals to ejaculation-related centers. The penis consists of the glans penis and penile shaft, which differ considerably in both histology and innervation. This paper aims to investigate whether the glans penis or the penile shaft is the main source of sensory signals from the penis and whether penile hypersensitivity affects the whole organ or only part of it. The thresholds, latencies, and amplitudes of somatosensory evoked potentials (SSEPs) were recorded in 290 individuals with primary premature ejaculation using the glans penis and penile shaft as the sensory areas. The thresholds, latencies, and amplitudes of SSEPs from the glans penis and penile shaft in patients were significantly different (all P < 0.0001). The latency of the glans penis or penile shaft was shorter than average (indicating hypersensitivity) in 141 (48.6%) cases, of which 50 (35.5%) cases were sensitive in both the glans penis and penile shaft, 14 (9.9%) cases were sensitive in the glans penis only, and 77 (54.6%) cases were sensitive in the penile shaft only (P < 0.0001). There are statistical differences in the signals perceived through the glans penis and the penile shaft. Penile hypersensitivity does not necessarily mean that the whole penis is hypersensitive. We classify penile hypersensitivity into three categories, namely, glans penis, penile shaft, and whole-penis hypersensitivity, and we propose the new concept of penile hypersensitive zone.