Care ‘n’ Cure Urology Clinic

The normal function of the bladder is to store and empty urine in a coordinated, controlled fashion. This coordinated activity is regulated by a complex interaction of the central and peripheral nervous systems. But what happens when the bladder malfunctions? This can be due to anatomic or neurologic anomalies from congenital defects, diseases or injuries. The information below will help define characteristics of a normal and abnormal bladder along with proper evaluation and management.

The urinary bladder is a spherical organ with unique properties that enable it to store and empty urine. The bladder is composed of two functional layers an inner urothelial lining and an outer smooth muscle layer. In addition to the bladder, the bladder neck is a funnel-like outlet of the bladder which leads to the urethra. It is also known as the internal sphincter. The urethra a tube-like structure which serves as a channel to carry urine from the bladder to the external surface, and the external urethral sphincters composed of striated muscles (group of muscles which surround the urinary passage distal to the bladder neck) complete the lower urinary tract.
The muscles and nerves of the urinary system must function in a coordinated fashion with the bladder in order to perform its two major functions of storage and elimination of urine. Nerves carry messages from the bladder to the brain and then from the brain to the muscles of the bladder telling them to tighten or release, allowing the bladder to empty during urination.
There are two main components to a normal micturition cycle of the bladder: storing and emptying. The bladder will initially fill (store urine) under a low pressure (high compliance). This requires both relaxation of the detrusor muscle along with its elastic properties of the bladder wall to enable the bladder to expand under low pressure. At the same time the striated sphincter is required to be contracted to maintain an elevated outlet resistance preventing urinary leakage. In order for the bladder to empty, the sphincter relaxes followed by a bladder contraction. Any abnormality in either component of the micturition cycle leads to bladder dysfunction.

Neurogenic bladder is the loss of normal bladder function caused by damage to part of the nervous system. The damage can cause the bladder to be underactive, in which it is unable to contract and unable to empty completely, overactive, in which it contracts to frequently without being able to be inhibited or inability to coordinate bladder contractions with sphincter relaxation (Detrusor Sphincter Dysnergey or DSD).

Risk factors for neurogenic bladder include various birth defects, which adversely affect the spinal cord and function of the bladder, including spina bifida or sacral agenesis and other spinal cord abnormalities. Tumors within the spinal cord or pelvis may also disrupt normal nervous tissue function and place an individual at risk. Traumatic spinal cord injury is also a major risk factor for development of neurogenic bladder.

When neurogenic bladder is suspected, both the nervous system (including the brain) and the bladder itself are tested. In addition to complete medical history and physical examination, diagnostic procedures may include:
Bladder function tests including Urodynamic evaluations, which has two components CMG (Cystometrogram) which measures bladder function, capacity, compliance and voiding and storage pressures. Along with EMG (Electromypography) which measures which help measure urethral sphincter tone and bladder coordination.
Radiologic imaging of the of the spine and brain including x-ray and MRI can be used
Imaging tests of the bladder and kidneys are performed

The main goal of Urologic management is to prevent damage to the upper tracts (kidneys). The secondary goal is minimize any social disabilities.
Medication for treatment of overactive bladder may improve or relieve irritating symptoms and/or incontinence. Other medications may improve bladder control by increasing outlet resistance at the bladder neck.
In 1981 Dr. McGuire observed that upper tract deterioration occurred when the detrusor leak point pressure exceeded 40cm/H20 measured by Urodynamics. Detrusor sphincter dysnergy (DSD) has also been found to be a significant risk factor for upper tract deterioration. Denervation of the external sphincter can lead to a fixed open sphincter resulting in bladder outlet obstruction. Both DSD and bladder outlet obstruction leads to bladder hypertrophy and loss of bladder compliance and decrease in capacity leading to elevated bladder pressures.

Clean intermittent catheterization (CIC) was developed by Dr. Jack Lapides in the early 1970s as a means of emptying the bladder in the case of a bladder muscle that is unable to contract or in patients with loss of appropriate coordination between the bladder muscle and the external urethral sphincter muscle (DSD). The same medications used to treat bladder over activity (anticholinergic medications) are used to help improve bladder storage pressures.
There have been numerous studies demonstrating that aggressive early management with patients with neurogenic bladders at high risk (patients with DSD or elevated bladder pressures) with CIC and anticholinergic medications have lead to decrease upper tract deterioration (kidney damage and failure) along with decreased need for future bladder augmentation surgery.
Surgical cutting or dilation of the external urethral sphincter with the use of an endoscope passed through the urethra and can eliminate the need for CIC in order to empty the bladder but at the expense of total urinary incontinence and frequently is only temporary.
At times, however, damage to bladder anatomy and function is so severe that capacity needs to be improved with bladder augmentation (increasing bladder size with various tissues), vesicoureteral reflux needs to be corrected and/or an alternate tube (catheterizable channel) for emptying the bladder may need to be surgically constructed for patients that are unable to catheterize through their urethras.

A person can expect extensive follow-up evaluation of bladder and kidney function. This may involve repeated X-rays, ultrasound, blood tests and bladder function tests.
Although some characteristics of the neurogenic bladder may improve or resolve, most issues typically require constant attention and reevaluation.
Proactive management of patients with a neurogenic bladder may decrease the risk of damage to the bladder and kidney(s) and, therefore, potentially limit the need for future intervention. This has been shown in management of neurogenic bladder patients with spina bifida.

The risk of neurogenic bladder is significant in this population and, therefore, careful and frequent evaluation of bladder function is recommended.