October 2, 2009 — Genital sensations of spontaneous unwanted imminent orgasm in women is a physical disorder that may be caused by pudendal neuropathy, and particularly neuropathy of the dorsal nerve of the clitoris (DNC), according to results from a study published online in the Journal of Sexual Medicine.
"Restless Genital Syndrome (ReGS) is highly associated with pelvic varices and with sensory neuropathy of the pudendal nerve and DNC, whose symptoms are suggestive for small fiber neuropathy," write Marcel D. Waldinger, MD, PhD, neuropsychiatrist and professor at the Utrecht Institute for Pharmaceutical Sciences and Neurosciences at Utrecht University, and in the Department of Psychiatry and Neurosexology at The Hague's HagaHospital Leyenburg in the Netherlands, and colleagues.
"Clinicians should not automatically attribute these complaints to sexual or psychological problems," Dr. Waldinger told Medscape Psychiatry. "Instead, a physical neurological examination of the genital region is required."
A Mysterious Disorder
ReGS is characterized by the presence of restless leg syndrome and/or an overactive bladder, as well as the 5 diagnostic criteria of persistent genital arousal disorder (PGAD).
These criteria include involuntary genital arousal that:
Persists for an extended period of time (hours, days, and/or months)
Does not go away after 1 or more orgasms
Is unrelated to subjective feelings of sexual desire
Feels intrusive and unwanted
Persistent sexual arousal syndrome was first reported in 2001 and was renamed PGAD 5 years later. Because of a lack of systematic research, the prevalence, etiology, and pathogenesis of this syndrome remain unknown, report the study authors.
"Since the first publication in 2001, persistent unwanted genital sensations in women have been considered a rather mysterious and rare disorder for which no explanation existed," said Dr. Waldinger.
He explained that an increasing number of women have come into his outpatient department during the past 5 years complaining of these sensations. "All of them were desperate, and some were even suicidal. To help these women was an important reason for me to investigate their complaints."
In an earlier study by Dr. Waldinger and his team, the majority of the 18 women evaluated experienced PGAD during early menopause without preexisting psychiatric disorders and laboratory abnormalities. However, 55% of the women did show varices as disclosed by magnetic resonance imaging (MRI) of the pelvis.
In addition, these patients reported preexisting or coexistent restless leg syndrome, overactive bladder, and urethra hypersensitivity. The investigators then renamed this combination of symptoms plus PGAD as ReGS.
In this study, Dr. Waldinger and colleagues sought to investigate distinct localization of ReGS through evoked sensory sensations.
A total of 23 women (median age, 56 years), who were diagnosed with ReGS after visiting the Outpatient Department of Neurosexology at HagaHospital between October 2004 and May 2009, were enrolled (including 12 from the previous study). Of these women, 15 were menopausal, 4 were premenopausal, and 4 were perimenopausal. The mean age at onset of the genital sensations, as reported by the women, was 51.1 years.
Although all the women reported varying degrees of social withdrawal, desperate feelings, dysthymia, agitation, or depressed mood directly caused by persistent unwanted genital sensations, none were known to have previous psychiatric disorders, report the study authors.
All patients underwent in-depth interviews, routine and hormonal investigations, an electroencephalogram, and MRI of the brain and pelvis.
Genital sensation localization was evaluated by physical examination of the ramus inferior of the pubic bone (RIPB) and by a genital tactile mapping test, which consisted of sensory testing of the skin of the genital area with a cotton swab in the presence of a nurse.
"Each pressure point was evaluated by instructing women to report the evoked sensations," write the authors.
At the end of the study, the electroencephalogram and MRI brain analyses showed nothing unusual in any of the women. Although the MRI of the pelvis showed no abnormalities of the clitoris and urethra, it did disclose a high prevalence of pelvic varices in the wall of the vagina (in 91% of the women), in the labia minora and/or majora (35%), and in the uterus (30%).
In addition, varices were found in the cervix of 9%, in the ovaric vene of 4%, and in a combination of locations in 69%. Finger touch investigation of the DNC along the RIPB provoked ReGS in all women.
The genital tactile mapping test showed that "static mechanical pressure provoked restless and pre-orgasmic genital sensations at different points."
The number of hypersensitivity trigger points varied among the patients (with a mean number of 5) and were located on the right side of the vagina and clitoris in 35%, on the left side in 26%, and bilaterally in 39%.
In addition, 48% had trigger points above the pubic bone, whereas for 17%, the clitoris was the sole trigger point.
"Sensory testing showed unilateral and bilateral static mechanical hyperesthesia on various trigger points in the dermatome of the pudendal nerve, particularly in the part innervated by the DNC, including the pelvic bone," write the study authors.
In 3 of the women, light static mechanical pressure induced an uninhibited and repeated orgasm during the examination at various trigger points.
Manifestation of Small Fiber Neuropathy?
"The spontaneous orgasm provoked by light touch was a surprise and has never been reported in the literature," said Dr. Waldinger. "It is caused by hyperesthesia of this part of the genital region. Hyperesthesia of the skin is a manifestation of small fiber neuropathy."
Intolerance of tight clothes and underwear was reported by 83% (n = 19) of the women, whereas sitting worsened the ReGS in 87% (n = 20).
Finally, restless leg syndrome, overactive bladder syndrome, and urethra hypersensitivity were reported in 78%, 69%, and 52% of the patients, respectively.
"Our findings of involvement of the pudendal nerve and DNC together with our findings of sensory genital sensations, clothes intolerance, and restless legs are argument in favor of small fiber neuropathy as underlying pathologic process in the pudendal and DNC neuropathy in women with ReGS," the authors write.
Further, pelvic MRI disclosed a very high prevalence of pelvic varices of different size in all the participants, suggesting that pelvic varices play an important role in the pathogenesis of the disorder. "Whether sensory neuropathy is induced by pelvic varices or other factors needs further investigation."
They add that a physical examination of the RIPB and sensory testing for static mechanical hyperesthesia can be used as diagnostic tests for ReGS and is "recommended for all individuals with complaints of persistent genital arousal in absence of sexual desire."
In a new study, Dr. Waldinger's team is investigating whether pelvic varices are causally related to the occurrence of pudendal and DNC neuropathy. They are also evaluating the use of transcutaneous electric nerve stimulation as a treatment for ReGS in the women from this study.
"The current study shows that, most importantly, small fiber sensory neuropathy of the pudendal nerve, and particularly its distal branch, is most likely the key disturbance of ReGS," said Dr. Waldinger.
The study authors have disclosed no relevant financial relationships.
J Sex Med. Published online September 2009.
Medscape Medical News © 2009 Medscape, LLC
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Cite this: Restless Genital Syndrome May Be Caused by Pudendal Neuropathy - Medscape - Oct 02, 2009.