Multiple Sclerosis and Neurogenic Bladder: Understanding the Problem

Introduction:

Urination is one of the most important physiological functions of the human body. It helps to remove toxic byproducts from the body. Also, helps to maintain water and electrolyte balance in the body. Excretion of urine is a complex process and is regulated by the action of the urinary bladder, urinary muscle, and neural stimulation. As a result, disruption in the neural pathway disrupts the excretion process of urine. Multiple sclerosis, which is a central nervous system disorder, often causes dysfunction in the bladder function.

What Is Multiple Sclerosis?

Multiple sclerosis is an autoimmune central nervous system disorder. This is the most common autoimmune disorder of the central nervous system that is responsible for the destruction of nerve cells and the destruction of the protective myelin sheath. Apart from this, this causes the excessive growth of fibrous tissue in nerve cells, such as glial cells. Around 2.5 million people around the world suffer from this condition. The activation of the T helper (Th) cells or CD4+ T-cells by the immune pathways is the main causative factor for this process. Also, infiltration of the other inflammatory cells and mediators destroys the myelin sheath. Additionally, conditions like this lead to inflammation in white and gray matter due to immune cell infiltration in specific areas of the brain and spinal cord. This causes several neurological abnormalities like difficulty in movement, improper muscle coordination, decreased stability, and difficulty in performing daily activities.

What Is a Neurogenic Bladder?

The urinary bladder is a pear-shaped hollow organ that is responsible for storing urine before the body empties it through urination. It is located in the pelvic cavity. Smooth muscles further regulate the process of urination. Detrusor (bladder) muscles provide the integrity of the urinary bladder. The internal urethral sphincter is located at the junction of the urethra and urinary bladder. It is under the control of the autonomic nervous system and provides involuntary control of urinary flow.

Neurogenic bladder is a medical condition that causes bladder and urinary sphincter dysfunction. This is caused due to problems in the central nervous system. The causative factors can be congenital, acquired, or traumatic. That is why, the classification of neurogenic bladder is based on lesions present in the different regions of the central nervous system. The classification is as follows:

1. Lesions Above the Pontine Micturition Center: The pontine micturition center is located in the dorsal pons of the brain and controls the urination process. In most cases, tumors and brain tumors are responsible for such lesions and dysfunction of the urinary bladder.

2. Lesions in Between the Pontine Micturition Center And Sacral Spinal Cord: These lesions are located in between the urination center of the brain and sacrum portion of the spinal cord. Traumatic injuries and diseases like multiple sclerosis are responsible for such complications.

3. Damage to the Detrusor Nucleus: The detrusor nucleus is located between the third and fourth sacral nuclei. This causes weakening of the detrusor muscle.

4. Sacral Cord Lesions: These types of lesions do not damage the detrusor nucleus but are responsible for damage to the pudendal nucleus. This nucleus is also known as Onuf's nucleus. The neurons of this nucleus originate from upper sacral segments of the spinal cord. These neurons control the muscles of the pelvic floor.

5. Lower Motor Neuron Lesions: These lesions are responsible for sacral nerve root injuries.

The symptoms of the neurogenic bladder are;

1. An increased frequency of urination.

2. Increased urge to urinate and such urges are not related to water consumption. In some cases, the amount of excreted urine is much less, and urges are often sudden.

3. Persons are often clueless about the bladder's fullness.

4. Inability to control urinary flow and, in some cases, sudden leakage of urine.

5. Pain during urination.

6. Repeated incidence of urinary tract infection which may cause blood in urine.

What Are the Relations Between Neurogenic Bladder and Multiple Sclerosis?

Various types of bladder dysfunctions and urinary complications are common in multiple sclerosis. Neurogenic bladder is one of the most common manifestations of such complications. Complication like the neurogenic bladder is seen in almost 30 to 90 percent of cases of multiple sclerosis. Demyelination of the nerve fibers is the root cause of neurogenic bladder in multiple sclerosis. The neural damage in the brain and the spinal cord often causes detrusor and external sphincter dyssynergia (abnormal movement of the muscles). This is seen in almost 60 percent of cases of multiple sclerosis. This is seen mainly in medullary lesions, which are located below the level of the pons and above the level of the sacral micturition center. However, neurogenic detrusor overactivity is mainly seen in lesions that are located above the pontine micturition center. The overactivity of the detrusor muscles often causes involuntary contraction of the detrusor muscles. If the lesions are intracranial lesions and involve the conus (tapered end of the spinal cord), they may cause inactivity of the detrusor muscle. This may lead to an incomplete void of urine and urinary retention. These types of complications are seen in almost 25 percent of cases. Though urinary complications are common in patients suffering from multiple sclerosis, the symptoms associated with this appear in much later stages of multiple sclerosis. In most cases, after six years of the diagnosis of multiple sclerosis, urinary symptoms appear.

However, such urinary complications may lead to severe disorders like,

1. Lower urinary tract infection due to retention of urine even after urination. It is seen in almost 30 percent of cases.

2. Morphological damage of the lower urinary tract is seen in 30 percent of cases. These damages include bladder diverticula, trabeculae, and parietal thickening of the urinary bladder.

3. In some cases, this may lead to bladder cancer.

What Are the Treatment Options?

The management of such complications needed help from urologists, neurologists, and rehabilitation physicians. The management includes both pharmacological and non-pharmacological management. These are;

1. Regular drinking of 1.5-2 liters (0.39 to 0.58 gallons) of water is advisable. However, late-night drinking of water is prohibited.

2. Regular physical exercise helps overcome the symptoms of multiple sclerosis. Exercise of the pelvic floor muscles helps treat detrusor muscle overactivity.

3. Peripheral tibial nerve stimulation is an effective way to treat such conditions. This is a neuromodulation method. Percutaneous tibial nerve stimulation (PTNS) is given through needles, and transcutaneous tibial nerve stimulation (TTNS) is given through pads in this procedure. A weekly 30-minute therapy for 12 weeks can be helpful.

4. Synthetic antidiuretic hormone desmopressin can be prescribed orally. This helps to reduce nighttime urinary frequency.

5. Onabotulinum toxin A is a special drug used in Botox treatment that can be useful in this condition. Intradetrusor injections of this drug help to reduce the incidence of sudden leakage of urine.

Conclusion:

Multiple sclerosis is responsible for neurological complications due to injury to the nerve structures. Urological complications are very common in such patients. Nerve injury is responsible for bladder dysfunction in these conditions. This leads to complications like sudden leakage of urine, urinary retention, and pain during urination. Physical exercise and medications can be useful in such cases.