The main 2 functions of urinary bladder are (1) storage of urine till it is time to empty and (2) Evacuation by passing urine periodically at appropriate times.
These 2 functions are achieved by finely co-ordinated processes of contraction and relaxation of detrusor muscle and urethral sphincters of bladder under control of centers of micturition in brain stem with inhibitory influence of cerebral cortex which occurs around 3-4 years. By 3-4 years majority of children stop daytime wetting. This fine balance of detrusor contraction and relaxations of sphincter are controlled by innervation of detrusor and sphincter muscles by sympathetic (T10, L1 spinal segment) parasympathetic (S2-S4 spinal segments) and motor/sensory nerves.
Disorders of voiding develop as incontinence or urinary retention if spinal segments of nerves are affected.
The clinical conditions commonly causing disorders of voiding are a variety of congenital and acquired conditions affecting spinal cord segments of dorsal lumbar, sacral regions including cauda equina and Conus medullaris ex. Meningomyelocele, lipomeningocele, diastematomyelia, spina bifida and sacral agenesis. Traumatic injuries and tumors of spinal cord are rare but important causes of
Causes of voiding dysfunction
Neurogenic causes: Meningomyelocele, lipomeningocele, spina bifida, sacral agenesis, diastematomyelia, tethering of spinal cord, Arnold Chiari malformation, trauma to spinal cord and rarely tumors of spinal cord.
Many of these conditions are associated with abnormal findings on neurological examination of lower extremities, abnormalities of feet, tuft of hair, nevus or dimple in the region of lower back and bowel dysfunction.
Non-neurogenic causes: Neuropathic or non-neurogenic / neurogenic bladder or Hinman's syndrome, monosymptomatic nocturnal enuresis, psychologic disturbances.
UTI, obstructive uropathy, vesicoureteral reflux, polyuric syndromes can easily be detected by good history, physical examination, urine culture and radiologic studies.