Persistent genital arousal disorder (PGAD) is an intrusive and debilitating condition that affects 0.6% to 3% of the female population worldwide. Although the exact cause of this disorder is not yet established, psychological, pharmacological, and neurological factors, including nerve compression, are suspected. This study aimed to evaluate the neurological and neurophysiological findings in women presenting with PGAD.

This is a retrospective study assessing neurological and neurophysiology findings in women with a clinical diagnosis of PGAD referred for a pelvic neurological assessment.  All patients referred for PGAD underwent a general and pelvic neurological examination by a neurologist documenting sensory and motor changes. A clinical scientist, unaware of the neurological findings, performed a battery of standardised pelvic neurophysiology tests that included tibial somatosensory evoked potentials (SEP), pudendal SEP, bulbocavernosus reflex study, needle EMG study from the anal sphincter muscle, and S2, S3, and S4 sacral dermatomal somatosensory evoked potential (dSEP) studies. The clinical scientist subsequently correlated all clinical symptoms noted in the clinical records with neurological and neurophysiological findings. Ethics approval REC reference: 24/LO/0638.

A total of 16 patients with suspected PGAD were referred to the Pelvic neurology services in the Department of Uro-Neurology between 2023-24  to assess an underlying neurological cause. All patients were female, with an average age of 50 years (range: 21-75). The mean duration of symptoms was 9 years. Neurological examination findings were abnormal in 6 patients (37.5%), which included hyperaesthesia and hyperpathia over the clitoris, labia, and perineum. Neurophysiology tests showed abnormalities in 14 cases (87%), including abnormal pudendal SEP (56%), S2 dSEP (44%), S3 dSEP (56%), S4 (56%), and EMG (25%) studies, as shown in Figure 1. Six patients (37.5%) were diagnosed with Tarlov cysts in the sacral area. Additionally, diabetes (1 case) and lumbosacral disc degeneration (1 case) were noted, as shown in Figure 2. Two patients had only pudendal SEP abnormalities, while four patients had only dSEP abnormalities.

Pelvic neurophysiology testing substantially increased the yield of detecting neurological abnormalities in women presenting with PGAD.  Two patients were found to have a pudendal neuropathy (abnormal pudendal SEP; normal S2,S3,S4 dSEPs), and four patients had a sacral root lesion (abnormal S2,S3 or S4 dSEP; normal pudendal SEP).   Needle EMG provided very little further information about these patients. Six patients (36%) declined the BCR study due to heightened sensation in the clitoris, and the remaining BCR studies did not reveal any isolated abnormalities where other tests were normal, suggesting that it is not a useful test for PGAD.  All six patients with sacral Tarlov cysts showed evidence for sacral root injury as per neurophysiology.

A substantial number of PGAD patients have objective evidence for neurological injury affecting either the pudendal nerve or sacral roots.  A subset of patients have Tarlov cysts, and in the remaining, intrapelvic nerve entrapment is suspected, which are potential therapeutic targets.   The Queen Square pelvic neurophysiology protocol can easily be set up in any centre that offers neurophysiology services, and patients tolerate the tests well.

(ISSWSH) review of epidemiology and pathophysiology, and a consensus nomenclature and process of care for the management of persistent genital arousal disorder/genito-pelvic dysesthesia (PGAD/GPD)’, The journal of sexual medicine, 18(4), pp. 665-697.