A male patient with a history of anorectal surgery reports a loss of pelvic sensation and control during intense physical activity and sexual stimulation, which he previously experienced as a grounding pelvic presence, what could be the cause of this symptom?

Post-Surgical Loss of Pelvic Sensation and Control

This patient is most likely experiencing pudendal nerve injury from anorectal surgery, resulting in impaired perineal sensation and pelvic floor proprioception that affects both physical performance and sexual function.

Most Probable Diagnosis: Surgical Pudendal Neuropathy

The "grounding pelvic presence" this patient describes represents proprioceptive feedback from the pelvic floor musculature and perineal sensory innervation, both supplied primarily by the pudendal nerve (S2-S4). 1 The loss of this sensation following anorectal surgery strongly suggests iatrogenic nerve damage.

Key Anatomical Vulnerabilities During Anorectal Surgery

• The inferior rectal branches of the pudendal nerve are particularly vulnerable during intersphincteric dissections and fistula surgery involving the intersphincteric space 1
• The pudendal nerve provides both motor innervation to the external anal sphincter and sensory innervation to the anal canal and perineum 1, 2
• Approximately 31% of individuals have additional direct S4 sacral nerve root supply to the external anal sphincter, creating variable vulnerability patterns 1

Clinical Manifestations Explained

Loss of "Grounding" During Physical Activity

• Impaired perineal sensation disrupts proprioceptive feedback essential for core stability and pelvic floor coordination during intense physical activity 3
• The pudendal nerve coordinates reflex pathways that contribute to pelvic floor muscle recruitment during exertion 2
• Unilateral pudendal neuropathy alone can significantly reduce both resting anal tone and squeeze pressures, indicating functional impairment even with partial nerve preservation 2

Sexual Dysfunction Component

• Patients with genital sensory loss preoperatively from pudendal nerve involvement typically have long-term impairment of sexual function 4
• The pudendal nerve supplies sensation to genital structures, and its damage eliminates the sensory feedback this patient previously used for sexual stimulation 5
• Persistent genital dysesthesia can occur after pelvic floor nerve injury, manifesting as altered or absent sensation 4

Diagnostic Evaluation Required

This patient needs anorectal manometry and pudendal nerve terminal motor latency (PNTML) testing to quantify the extent of nerve and sphincter dysfunction. 4

Specific Testing Protocol

• Anorectal manometry can identify anal weakness, reduced rectal sensation, and impaired pelvic floor coordination 4
• Pudendal nerve terminal motor latency testing establishes whether unilateral or bilateral neuropathy is present 2
• Unilateral pudendal neuropathy occurs in 38% of patients with fecal symptoms and significantly reduces both resting pressures and squeeze increments 2
• Endoanal ultrasound or MRI should be performed to assess for sphincter defects, atrophy, or structural damage from the surgery 4

Correlation of Findings

• At baseline, PNTML correlates with anal electrosensitivity (r = 0.461, P = 0.003), confirming the relationship between motor and sensory pudendal function 3
• Age significantly correlates with both anal sensation (r = 0.45, P = 0.004) and PNTML (r = 0.49, P = 0.002), which may influence recovery potential 3

Management Approach

Conservative Management First-Line

Pelvic floor biofeedback therapy should be the initial treatment to retrain remaining pelvic floor function and improve proprioceptive awareness. 4

• Biofeedback can improve pelvic floor strength, sensation, contraction coordination, and rectal sensation 4
• This approach is particularly effective for patients with anorectal dysfunction following surgery 4

Advanced Therapeutic Options if Conservative Measures Fail

• Pudendal neuromodulation (chronic pudendal nerve stimulation) may restore some sensory function and improve pelvic floor coordination 5
• In a case series of pudendal neuromodulation, 3 of 4 patients met their treatment goals and reported satisfaction, with improvement in chronic pelvic pain (4/4), bowel function (3/4), and bladder function (3/4) 5
• Sacral nerve stimulation (SNS) is FDA-approved for fecal incontinence and may improve pelvic floor coordination through reflex pathway modulation, though its mechanism remains incompletely understood 4

Critical Surgical Contraindication

Surgical intervention involving muscle cutting is absolutely contraindicated for functional pelvic floor disorders, as it causes permanent damage with high risk of fecal incontinence without addressing nerve-based problems. 6

Prognosis and Expectations

• Recovery of pudendal nerve function after surgical injury is variable and depends on the extent of nerve damage 4
• Patients with some preservation of perineal sensation have better outcomes than those with complete sensory loss 4
• The acute changes in anal sensation and PNTML that occur with straining typically return to baseline after 3 minutes in normal individuals, but chronic neuropathy prevents this recovery 3

Red Flags Requiring Urgent Evaluation

• Development of urinary retention, fecal incontinence, or perineal anesthesia suggests cauda equina syndrome and requires emergency MRI 4
• Progressive neurological deficits in the legs or bilateral radiculopathy are definite red flags for cauda equina compression 4
• These symptoms would indicate a more extensive neurological injury requiring immediate neurosurgical consultation 4