# Handbook of Genetic Counseling/Incontinence

Incontinence

## General Information

* Refers to inability to retain urine in bladder
* Due to neurologic or mechanical disorder
* Normal bladder function
** Detrusor muscle provides propulsive force for emptying bladder
*** Smooth muscle under parasympathetic autonomic control
*** Involves pelvic nerves from sacral spinal cord
** Layer of smooth muscle of trigonal part of bladder acts as involuntary internal sphincter
*** Helps prevent incontinence even if no voluntary control
*** Innervated by motor fibers from T11 to L2
** External sphincter and perineal muscles under voluntary control of pudendal nerves
** Sensory tracts of pain, temperature, and distention pass from bladder to pelvic nerves to sacral spine to medulla of brain to cortical centers
* Infants and adults with spinal damage above S2 urinate spontaneously when bladder fills

## Causes of Incontinence

* Detrusor instability
** Bladder prone to uncontrollable contractions
** Caused by damage to inhibitory neural pathways (70% of incontinence among elderly)
*** Cerbrovascualr accidents
*** Alzheimer's disease
*** Neoplasia
*** Hydrocephalus (?maybe?)
** Could also be caused by bladder or pelvic infection or tumor, fecal impaction, uterine prolapse, and prostate hypertrophy
** May be treated with Imipramine or calcium channel blockers
* Stress incontinence
** Common in postmenopausal parous women
** Structures of female urethra atrophy when deprived of estrogen
*** Pass urine under increased abdominal pressure during coughing, sneezing, climbing stairs
*** Physical activity may result in small amount of urine escaping
* Mechanical incontinence
** Congenital anomalies, extrophy of bladder, patent urachus, and ectopic ureteral openings
** Correctable by surgery only
** May also be caused by prostate surgery, pelvic surgery, or irradiation of uterus or rectum
* Overflow or paradoxical incontinence
** Large residual volumes of urine
** Secondary to obstruction at bladder neck or urethra, or neurologic damage
** May occur in diseases that produce autonomic peripheral neuropathy
*** Diabetes mellitus, uremia, hypothyroidism, chronic alcoholism, Guillain-Barre syndrome, collagen vascular diseases, and toxic neuropathy caused by carcinomas
*** Also may be due to prolonged distension of bladder
** May be treated surgically if obstruction or with bethanechol chloride
* Psychogenic and functional incontinence
** Occurs in children and some adults
** May be to draw attention to themselves
** May have psychological cause from abuse or other traumatic experiences
* Enuresis
** Involuntary passage of urine at night during sleep
** Considered normal under age of 2 years as neurological controls are still developing
*** Approximately 10% of children have some degree of enuresis beyond age of three
**** May be due to delay in maturation of bladder control
**** May be familial
*** Usually ceases by age of puberty unless disease interferes
**** Urinary tract infections, obstructive lesions, neurovesical dysfunction, and polyuric conditions that overload the bladder
**** Usually incontinent during the day also if one of these conditions

## Reference

* "Dysuria, Frequency and Urgency, Incontinence, and Enuresis." Principles of Internal Medicine (1994): 240-241.

## Notes

The information in this outline was last updated in 2002.