Chronic Pelvic Pain

What is Chronic Pelvic Pain?

Chronic pelvic pain (CPP) is an umbrella term that captures a wide range of diagnoses that cause persistent pain in the pelvis last greater than three to six months. CPP affects both men and women with an estimated prevalence as high as 40%. (1, 2, 3) The occurrence of CPP may be predated by traumatic physical or psychological event(s). Physical causes can be categorized into blunt pelvic injury, surgery/procedures, infection or disease process affecting the pelvic area, bladder and reproductive organs. CPP may also manifest as a part of another ongoing disease such as irritable bowel syndrome, fibromyalgia, chronic fatigue syndrome, posttraumatic stress disorder (PTSD) and depression. Although there are established risk factors to develop CPP, the exact cause remains unknown.

A network of nerves richly supplies the structures surrounding the pelvis, such as the coccyx (the tailbone), genitalia, anus, rectum, and skin overlying the saddle region. Any damage to this sensitive area may potentially alter the typical architecture and sensory pathway of the nervous system, which results in severe nerve pain. Maladaptive changes cause the brain to interpret non-painful stimuli as painful with significant amplification. Similar to other nerve pain conditions, CPP is complicated, may spread, and tend to evolve. The contribution from the nearby “fight or flight” autonomic nervous system causes CPP to fluctuate and worsen under emotional and environmental stressors. (4) Individuals with CPP may suffer silently, given the stigma and often-complicated history.

It is important to note that CPP is a diagnosis of exclusion. Before considering the condition as CPP, all anatomical and physiological causes must be judiciously worked up and addressed. (5) Because a large number of potential diagnoses originate in a relatively small anatomical region, the recognition and the diagnosis of CPP are often delayed. (3)
 
What Are the Signs and Symptoms of Chronic Pelvic Pain?

CPP has been considered potentially as a variant complex regional pain syndrome (CRPS) that affects the pelvic region in much the same way it would the extremities. (6) The typical signs and symptoms are the following:
-    Hyperalgesia, i.e., out-of-proportion pain
-    Allodynia, i.e., a normally non-painful stimulus is perceived as painful
-    Skin changes
-    Worsened by emotional or environmental stressors or routine physiological functions and activities of daily living (defecating, voiding, sexual intercourse and sitting, donning and doffing clothes)

How is Chronic Pelvic Pain Treated?

Studies found that people with CPP are at greater risk to use pain medications, or undergo surgery, including hysterectomy, to treat CPP, compared to their healthy peers. (7) Unfortunately, surgeries are often ineffective or possibly worsen the preexisting pain. (8, 9) Therefore, treatment mainly centers on combining nerve pain medication, physical therapy, and behavior therapy to manage symptoms conservatively. (10) Interventional pain procedures have also been shown to be helpful. (4, 11)
Pharmacological interventions:
-    Anti-inflammatory medication, such as ibuprofen
-    Membrane stabilizing medication, including anticonvulsants and antidepressants
-    Steroids
-    Hormone therapy
Physical therapy:
-    Biofeedback
-    Desensitization techniques
-    Pelvic floor rehabilitation
-    General aerobic and strengthening exercises
Behavioral therapy:
-    Counseling
-    Cognitive behavioral therapy
Interventional Techniques:
-    Hypogastric block
-    Ganglion of impar block
-    Nerve blocks

Regrettably, in more severe cases of CPP, both conservative and interventional techniques tend to fail over time or only provide partial relief. Furthermore, repeated injections and nerve blocks carry risks that may preclude certain patients from receiving repeated injections. (4, 12)

Is Neuromodulation Useful for Treating Chronic Pelvic Pain?

Yes, there are a number of reports of successful use of neuromodulation to treat CPP. Both traditional spinal cord stimulation and peripheral/sacral nerve stimulation were shown to be useful for treating CPP. (13-18) One advantage of neuromodulation is that in most cases of CPP, symptoms persist in the absence of a target to fix procedurally or surgically. Neuromodulatory techniques are minimally invasive and interrupt pain at the level of the brain, spinal cord, and peripheral nerves. Notably, in the recent advancement in dorsal root ganglion stimulation, a sub-type of spinal cord stimulation, there have been reported cases of unprecedented pain reduction and therapy durability. (18, 19) Given that neuromodulation is effective, safe, reversible, and cost-effective, it is receiving increasing interest from patients and providers in addressing CPP. (21) Further research should continue to clarify the evidence base for treating CPP with neuromodulation.

Chronic Pelvic Pain
(2-minute video 2018)

References

Submitted May 27, 2018
Ajax Yang, MD
Patient Education Committee Member, International Neuromodulation Society
Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai
New York, New York, USA

Corey W. Hunter, MD, FIPP
Patient Education Committee Co-Chair, International Neuromodulation Society, 2017 -
Executive Director
Ainsworth Institute of Pain Management
New York, New York, USA

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