HYPERSENSITIVITY OF THE BLADDER

The hypersensitivity of the bladder should not be confused with OAB (Overactive Bladder)

Summary

Bladder hypersensitivity is a complex and often underdiagnosed condition that significantly impacts patients’ quality of life. It is frequently mistaken for overactive bladder (OAB) or urinary tract infections (UTIs) due to overlapping symptoms. Bladder hypersensitivity should always be suspected when there are symptoms of urgency, urgency incontinence, and frequency – similar to a bladder infection or overactive bladder – in the following cases:

When no bacterial infection has been proven, especially if antibiotic treatments have not been effective.
When all treatments for overactive bladder (OAB), including bladder Botox injections, bladder hydrodistension/instillations, or pelvic nerve stimulation (SNM), have not provided relief.
When you are labeled with ‘IC’ (interstitial cystitis) without any histological proof of interstitial cystitis.”
When you are labeled with Bladder Pain Syndrome, Chronic Pelvic Pain Syndrome, or any other “Syndrome”, which diagnosis you have to accept without any corresponding clear treatment.

Effective diagnosis involves ruling out other common bladder disorders, while treatment requires a holistic approach, addressing both Uro-gynecological and Neuropelveological aspects. The treatment must be adapted to each specific situation and should focus primarily on addressing any possible underlying cause. This means that every patient is unique, and care should be personalized based on the identified causes, rather than relying solely on a standard treatment approach. Early intervention can help patients manage their symptoms and avoid complications like social isolation, sleep disturbances, and chronic pain. Collaborating with specialists in urology, gynecology, and neuropelveology can optimize care and improve outcomes for patients with this challenging condition.

Introduction

Bladder hypersensitivity is a condition characterized by an exaggerated response of the bladder to sensory signals, often leading to discomfort, urgency, and frequent urination. It is often mistaken for overactive bladder (OAB) or urinary tract infections (UTIs) due to overlapping symptoms. Understanding the nature of bladder hypersensitivity, its causes, symptoms, and treatment options is critical for patients experiencing chronic bladder issues.

Diagnosis

Bladder hypersensitivity can be difficult to diagnose due to its similarity to other bladder conditions. Urodynamic tests often show normal results, and treatments for OAB or UTIs typically fail, leading to a diagnosis based on clinical symptoms and patient history. A comprehensive neurological evaluation may be required to rule out other causes such as neurogenic disorders.

Common tests used to rule out other conditions include:

Urinalysis and urine culture to check for infections.
Cystoscopy to look inside the bladder for structural issues, especially< for exclusion the diagnosis of an interstitial cystitis – also called IC.
Urodynamic testing to assess how well the bladder and urethra are storing and releasing urine – this is the main difference with an overactive bladder (OAB) which demonstrates an increase of bladder pressure while filling it with saline solution.
Pelvic MRI for evaluating potential nerve involvement or damage.

INNERVATION OF THE BLADDER AND SPHINCTERS

The bladder and sphincters are controlled by a network of nerves that ensure they work properly.

Bladder:
- Nerves that relax the bladder and help it fill: This is mainly controlled by the Sympathetic Nervous System. It helps the bladder store urine and prevents it from emptying until it’s appropriate. These nerves come from the spinal cord in the lower thoracic and upper lumbar regions (T10–L2).
- Nerves that empty the bladder: When it’s time to empty the bladder, the Parasympathetic Nervous System activates the muscles in the bladder wall (called the detrusor muscle) to contract, allowing urine to flow out. These nerves come from the lower part of the spinal cord (S2–S4).
Sphincters:
- Internal sphincter: This involuntary sphincter is controlled by the Sympathetic Nervous System and helps keep urine in the bladder when it is full.
- External sphincter: This is the voluntary sphincter that we can consciously control when we decide to urinate. It is controlled by nerves from the Somatic Nervous System, also from the S2–S4 region.

Together, these nerves ensure that the bladder empties when we’re ready and holds urine when we’re not. If there is a problem with the nervous system or bladder function, issues like incontinence, OAB, hypersensitivity or difficulty urinating can occur.

While OAB is a condition affecting the motor nerves of the bladder (Parasympathetic nervous System), hypersensitivity is a condition affecting the sensory nerves of the bladder (Sympathetic Nervous System). Thus, if the treatment for OAB consists of measures to relax the bladder, these same treatments do not work for treating hypersensitivity. In the latter situation, the treatment is based on blocking the sensory nerves with medications (side effects – never end treatment…), or – and this is the neuropelveological approach – treating the cause of the overactivity of the sensory nerves of the bladder.

SYMPTOMS

The primary symptoms of bladder hypersensitivity are similar to those seen in OAB but include some distinctive features:

Urgency: A sudden, intense need to urinate that can occur even when the bladder is not full.
Frequency: An increased need to urinate, often more than 8 times in a 24-hour period.
Nocturia: Waking up multiple times during the night to urinate.
Discomfort or pain: As the bladder fills, discomfort or mild pain may occur even in the absence of an infection.
Increased bladder sensation: Heightened or abnormal sensations in the bladder, sometimes described as an ongoing sense of fullness.
Urgency without frequency: Feeling the urge to urinate without actually needing to go more often.

RISK FACTORS

Several risk factors have been identified for bladder hypersensitivity:

Age and Gender: The condition is more prevalent in women, particularly those over 40.
Pelvic Surgeries: Surgeries causing nerve damage or fibrosis may contribute to bladder hypersensitivity.
Chronic Pelvic Pain Syndromes (CPPS): Conditions such as interstitial cystitis (IC), vulvodynia, and prostatodynia can overlap with or exacerbate bladder hypersensitivity.
Neurological Disorders: Patients with spinal cord injuries (SCI) or multiple sclerosis (MS) are at increased risk.
Endometriosis: This gynecological condition has been linked to increased bladder sensitivity due to pelvic nerve involvement.

CAUSES

In daily practice, bladder hypersensitivity is almost always attributed to recurrent bladder infections, so in gynecology, the first therapeutic approach is always the administration of antibiotics, with or without confirmation of an actual bacterial infection. The second step is the referral of the patient to a urology colleague. In the absence of confirmation of bladder overactivity through urodynamic testing, the urologist may hypothesize interstitial cystitis.

As a result, the patient will need to undergo cystoscopy with a bladder biopsy. Given the prevalence of this condition, also called “IC,” which ranges from 0.1% to 1% of the general population, this diagnosis will be confirmed histologically in only a small minority of patients.

From then on, their medical wandering begins, without receiving an effective treatment. At this point, the neuropelveology specialist does not initially see the problem at the bladder level itself but rather at the level of the bladder nerves. These pelvic nerves can be damaged or irritated by several pelvic pathologies, including the following conditions:

1. Neurogenic causes:

Disorders like SCI, Polyneuropathy and MS can affect the nerves that control bladder function, leading to hypersensitivity.

2. Pelvic neuropathies by Vascular entrapment:

Conditions like pelvic vascular entrapment can lead to nerve irritation and heightened bladder sensitivity. Pelvic neuropathies are conditions where the nerves in the pelvic and lower back regions are compressed or irritated. This often causes severe, long-lasting nerve pain, which can also bring other symptoms. In many cases, this pain is called “Chronic Pelvic Pain Syndrome of unknown origin.” One common cause of these nerve problems is vascular entrapment, where blood vessels press on nerves, leading to pain and other issues. While this problem has been well-known in other parts of the body, it was first discovered in the pelvic area in 2011 by Dr. Possover. The nerves most affected by this condition include the pudendal nerve, sciatic nerve, and sacral plexus, which can cause pain in the lower back, pelvis, or legs, as well as bladder and bowel problems.

Vascular entrapment can happen due to:

Abnormal Blood Vessels: Sometimes blood vessels have unusual shapes or locations, which can press on nearby nerves.
Enlarged Vessels: Conditions like varicose veins or aneurysms (bulging blood vessels) can also lead to nerve compression.

It’s important to identify these blood vessel problems to understand why the nerve pain is happening and to choose the right treatment. In some cases, autoimmune diseases, where the immune system attacks the body’s tissues, can lead to inflammation or blood clots that contribute to nerve compression. That’s why it’s crucial to review a patient’s medical history for autoimmune or blood conditions when diagnosing and treating pelvic nerve pain.

Doctors, including specialists in nerve and pelvic conditions – neuropelveologists (see www.theison.org), but also urologists, and gynecologists, should always ask about the risk of blood clots or vascular problems. This is because a correct diagnosis will help ensure the most effective treatment, which will directly impact how well the treatment works.

For pain management specialists or any doctor dealing with pelvic issues, it’s important to consider pelvic neuropathy due to vascular compression, especially in patients with autoimmune conditions like Ehlers-Danlos syndrome. If a patient’s nerve pain improves or disappears when they lie down at night, this may be a sign of nerve compression caused by blood vessels.

3. Endometriosis of the Inferior Hypogastric Plexus and Visceral Pain

Endometriosis is a chronic condition in which tissue similar to the lining of the uterus (endometrium) grows outside the uterus, affecting various pelvic structures. One less commonly discussed but significant form is when endometrial tissue invades or irritates the inferior hypogastric plexus (vegetative nerves), a network of nerves responsible for innervating pelvic organs like the bladder, uterus, and rectum.

The inferior hypogastric plexus plays a central role in controlling visceral sensations and functions of these organs. When endometrial lesions infiltrate this nerve plexus, it can lead to nerve entrapment or irritation, causing severe visceral pain. This type of pain is deep, poorly localized, and often experienced as a constant dull ache, cramping, or stabbing sensations in the lower abdomen, pelvis, or back.

Women with endometriosis in this area often report symptoms such as:

Chronic cyclical pelvic pain (mainly during menstruation)
Painful urination (dysuria) and Bladder Hypersensitivity
Pain during bowel movements, alternance constipation/diarrhea especially during menstruation
Pain during sexual intercourse (dyspareunia)

As mentioned, an attack on the vegetative nerves will spread like a wild fire to the entire vegetative system of the whole body and will induce a host of symptoms and clinical signs that are easy to recognize for those who seek them and want to see them:

Saliva production in the mouth is reduced, resulting in dry mouth and lips (often with chapped lips)
Dilation of the pupils (called mydriasis)
Palpitations, accelerated cardiac activity (tachycardia)
A pale face, often with red-patches of stress on the neckline at the same time.
Increased sweating in the armpits and the hands
Significant fatigue, lack of energy, desire to do nothing
Episodes of anxiety, depression, or both
Mood swings from one moment to the next, with more aggressiveness during menstruation
Nausea or even vomiting, loss of appetite
Episodes of syncopation, dizziness or even loss of consciousness (it’s not dramatization!).
Diaphragm spasms with chest pain radiating into the shoulders or arms (not just right as in diaphragm endometriosis, but also left side), with difficulty for breathing
Abdominal bloating with more constipation outside menstruation
Stomachal Pain with burping
Disorders of the immune system with tendency to “be sick more often”.

For more information on these “vegetative symptoms”, please see: https://blog.possover.com/en/endometriosis-the-praying-mantis-within-the-pelvis

4. Endometriosis of the pelvic nerves (sacral plexus)

Sacral plexus endometriosis is a rare but significant condition that often leads to confusion with sciatic nerve endometriosis due to the similarity in their names. However, these two conditions are entirely different in terms of symptoms, diagnosis, and treatment.

Sacral plexus endometriosis involves the infiltration of deeply infiltrating endometriosis form the uterus into the nerves of the sacral plexus, which can cause severe pelvic combining lower back/gluteal/leg pain, as well as genitoanal burning pain and hypersensitivity of the bladder and of the rectum – and in only rare extreme situation neurological symptoms like numbness or weakness in the legs. The pain is often cyclical, worsening during menstruation, and can sometimes be mistaken for other causes of pelvic nerve pain.

In contrast, sciatic nerve endometriosis affects the sciatic nerve itself, leading to symptoms like shooting pain down the leg, numbness, and difficulty in movement, often mistaken for sciatica. This condition can also be cyclic, with symptoms intensifying around menstruation, but the focus of the pain is along the path of the sciatic nerve.

In summary, although sacral plexus and sciatic nerve endometriosis share a similar name, they are distinct in their anatomical location, symptoms, and treatment approaches. Understanding the difference is crucial for accurate Neuropelveological diagnosis and effective adapted management.

5. Pelvic Surgeries:

Damage to the pelvic nerves during surgeries or due to injury can cause the bladder to become hypersensitive. During pelvic surgeries, there is a risk of irritation or injury to the nerves in the pelvic area. These nerves play a crucial role in controlling functions like bladder, bowel, and sexual activity, as well as sensation in the lower back, pelvic region, and legs. While doctors take every precaution to avoid nerve damage, it’s important to understand how this can happen and what it means for your recovery.

What Causes Nerve Irritation or Injury? During surgery, pelvic nerves can sometimes be irritated by surgical tools, pressure from surrounding tissues, or direct injury. The most common causes of nerve irritation or damage include:

Pressure: If nerves are compressed during surgery, it can cause temporary irritation or discomfort.
Direct Injury: Accidental cutting or stretching of a nerve can lead to pain, numbness, or weakness in the areas controlled by that nerve.
Scar Tissue: After surgery, scar tissue may form around the nerves, potentially leading to long-term discomfort or pain.

Symptoms of Nerve Injury If a pelvic nerve is irritated or injured, you might experience some of the following symptoms depending from which are damages:

Orthopedic symptoms: Pain in the lower back, pelvis, or legs
Gynecologic symptoms: Pain in the genito-anal areas, pudendal pain, vulvodynia…
Urologic symptoms: Hypersensitivity of the bladder and colon irritable.

TREATMENTS

Treatment for bladder hypersensitivity is often tailored to the underlying cause, if identified, and may involve a neuropelveological approach:

Laparoscopic exploration/decompression of pelvic nerves, evt with resection pelvic/nerves endometriosis or nerves release: The biggest challenge in neuropelveological surgery is not knowing how to expose the pelvic nerves via laparoscopy, but rather knowing which nerves need to be examined, wherein the pelvis they are located, and what should be done at the level of the nerves. This field is not one of gynecology, but rather neurovascular surgery of the pelvic nerves. Thus, the essential part of neuropelveology is not the surgery—which, nonetheless, is very dangerous in non-expert hands—but the diagnostic aspect, which involves a neurological diagnosis applied to the pelvic nerves—a neuropelveological examination that has nothing to do with a urological or gynecological examination. This falls under the domain of a Level 3 ISON-certified neuropelveologist with many years of experience (possover-neuropelveology.com)
The Genital Nerves Stimulation – The GNS therapy is the only neuromodulation therapeutic approach that allows for both the stimulation of the nerves of the bladder and rectal sphincters (pudendal nerves) and the sensory nerves of the bladder (autonomic nerves). Thus, GNS therapy enables treatment for both bladder overactivity and bladder hypersensitivity.
The infiltration of the inferior hypogastric plexus (also known as the pelvic plexus) with Botox (Botulinum toxin) is a therapeutic intervention used in specific clinical situations to relieve chronic pelvic pain. It is particularly considered in patients with chronic pelvic pain or pelvic floor dysfunction caused by hyperactivity of the nerves in this region. Botulinum toxin is a neurotoxin that inhibits the release of acetylcholine at nerve endings, reducing muscle activity. It also acts on nerves by blocking the transmission of pain signals. When Botox is injected into the inferior hypogastric plexus, it suppresses excessive nerve activity that leads to pain or dysfunction. The effect is temporary, but pain relief may last for several months.

Publication

Voiding Dysfunction Associated with Pudendal Nerve Entrapment – M. Possover – A. Forman. Link

For more information

Don’t hesitate to contact the POSSOVER Medical Center in Zurich if you have some questions