This patient is suspected to have difficulty in micturition accompanying paraparesis. Would you like to ask him a few questions'?
Proceed as follows:Ask the patient the following questions:· Do you get a sensation when the bladder is full'?· Do you feel the urine passing'?· Are you able to stop urine passing in midstream at your own will'?· Does the bladder leak continually'?· Do you suddenly pass large volumes'?· Is there any difficulty in defaecation?· ls there any numbness in the perineal region'?Tell the examiner that in a male patient you would like to take a history of impo-tence and examine the neurological system andspine.
This patient has a spastic bladder (lesion) accompanying his paraparesis which occurred as a result of trauma (aetiology) andrequires an indwelling urinary catheter (functional status).
What are the types of neurogenic bladder?
Spinal or spastic bladderThe bladder is small and spastic and holds less than 250 ml. It is seen in lesions of the spinal cord secondary to trauma, multiplesclerosis, and spinal cord tumour (upper motor neuron lesion). Bladder fullness is not appreciated and the bladder tends to emptyreflexly and suddenly - the automatic bladder. Evacuation may be incomplete unless the bladder is massaged by pressure in thesuprapubic region.The autonomous bladderThis resultsfrom damage to the cauda equine, i.e. lower motor neuron lesion. The patient is incontinent with continualdribbling and there is no sensation of bladder fullness. Despite the dribbling there is considerable residual urine. There is loss ofperineal sensation and sexual dysfunction. (ln conus medullaris-cauda equine lesions, it is possible to have a flaccid lower motorneuron detrusor with a spastic sphincter. The reverse may also occur.)The sensory bladderThis is similar to autonomous bladder and is seen in tabes dorsalis, subacute combined degeneration of the cord and multiplesclerosis. There is loss of aware-ness of bladder fullness with a loss of spinal reflex. This results in retention of large quantities ofurine, incontinence with dribbling, and a high volume of residual urine which can be voided by considerable straining.The uninhibited bladderThis occurs with lesions affecting the second gyrus of the frontal lobe, e.g. frontal lobe tumours, parasagittal meningiomas,aneurysms of the anterior communicating arteries and dementia. Patients have urgency despite low bladder volumes and havesudden uncontrolled evacuation. There is no residual urine. When there is deterior-ation of the intellect, the patient may pass urineat any time without concern.
What do you know about the neurological control of the bladder?
* Micturition follows activation of the parasympathetic pathways to the detrusor muscle and inhibition of the somatic input to theexternal urethral sphincter. The parasympathetic reflex is based in the S3 roots and S3 segments of the cord.· The sympathetic system promotes urinary storage by increasing urethral resistance and depressing detrusor contractions. Thesympathetic supply descends into the pelvis from the hypogastric reflex.· A cortical representation of the bladder is present in the paracentral lobule, stimulation of which may evoke bladdercontractions. It may play a part in initiating voluntary contractions and in stopping micturition by initiating contrac-tion of theexternal sphincter.
What investigations are performed to evaluate bladder function?
Cystometry, sphincter electromyography, urofowmetry with measurement and recording of urinary flow, urethral pressure profiles,and electrophysiological tests of bladder wall innervation.
What are the different types of urinary incontinence?
Urinary continence is dependent on a compliant reservoir (the bladder) and sphinc-teric efficiency which relies on its twocomponents: the involuntary smooth muscle of the bladder neck and the voluntary skeletal muscle of the external sphincter. Urinaryincontinence occurs when urine leaks involuntarily and is of five types:· Total incontinence: the patient loses urine at all times and in all positions. It occurs when the sphincter is damaged (by surgery,cancerous infiltration and nerve damage) or when there is a fistula between the urinary tract and the skin, or ectopic ureters.· Stress incontinence: occurs when there is an increase in intra-abdominal pressure (on coughing, sneezing, lifting, exercising). Itis seen in patients with a lax pelvic floor (e.g. multiparous women, patients who have undergone pelvic surgery). Patients donot lose urine in the supine position.· Urge incontinence: loss of urine preceded by a strong, unexpected urge to void urine. It occurs with inflammation or neurogenicdisorders.· Overflow incontinence occurs in chronic urinary retention from a chronically distended bladder.· Enuresis: a form of involuntary nocturnal incontinence. It is usually seen in children.