How neurological conditions affect bladder function

The majority of individuals who suffer from neurological conditions have partial damage to the nerve pathways. The type of bladder disorder that occurs depends on what area (and level) of the brain or spinal cord is affected:

• Suprapontine lesions ie lesions above the pons
• Brain stem/pons lesions
• Suprasacral lesion ie lesions above sacral area and below the pons
• Sacral, cauda equina, pelvic nerve lesions
• Pudendal nerve lesions

Damage within theses areas tends to produce specific characteristics and patterns of bladder and sphincter dysfunction which can help to locate where the source of the dysfunction is.

Assessment needs to identify the site of the neurological lesion to understand what nerve pathways are damaged.

^{Figure 3:4: Neurological levels.}

As can be seen from this diagram a stroke can cause suprapontine lesion (damage to the cortical micturition centre) or a lesion in the pons (brain stem).

The treatment for a suprapontine lesion is different to the treatment for a pons lesion. Therefore you need to understand the type of lesion before you can treat.

What bladder/sphincter dysfunction will occur at the different neurological sites?

• Suprapontine lesion – neurogenic overactive bladder
• Pons lesion – detrusor-sphincter dyssynergia, bladder outlet obstruction
• Suprasacral lesion – overactive, dyssynergia and unstable detrusor contractions incomplete bladder emptying due to the bladder outlet obstruction
• Sacral, cauda equina, pelvic nerve lesions – Hypotonic/atonic bladder incomplete bladder emptying
• Pudendal nerve lesions – incompetent urethral sphincter stress incontinence

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