Uroneurological assessment of spina bifida cystica and occulta

Spina bifida is a rare but well-documented congenital spinal anomaly comprising a cystic form, which appears in infancy, and an occult form, which appears in late childhood and in adulthood. Herein, we report the results of uroneurological assessment in patients with spina bifida cystica and occulta, with respect to diagnosis and management of the disorders.

We performed a neurological examination, urinary questionnaire, and urodynamic studies in 28 consecutive patients with urinary symptoms, including 16 with the cystic form (nine male and seven female patients, ages 2 to 25 years), all of whom underwent neonatal surgical management, and 12 with occult form (six men and six women, ages 7 to 32 years) diagnosed by myelography and spinal magnetic resonance imaging who did not undergo surgery.

Neurological examination revealed a combination of flaccid and spastic paresis, with dominant lower motoneuron signs in the cystic form, whereas there were dominant upper motoneuron signs in the occult form. Four patients with occult spina bifida presented with urinary symptoms as the sole initial complaint. There was no correlation between neurological findings and urodynamic abnormalities. Urinary incontinence and enuresis were common at all ages, and large post-micturition residuals and vesicoureteral reflux were not uncommon, particularly in the cystic form. Bladder abnormalities in the cystic and occult forms included detrusor hyperreflexia during filling in 38% and 42%, low compliance detrusor in 81% and 67%, supersensitivity to bethanechol in two (100%) patients with the cystic form and in three of four (75%) with the occult form, and impaired bladder sensation in 25% and 8% in each form, respectively. Urethral abnormalities in cystic and occult forms included detrusor/sphincter dyssynergia in 50% and 27%, low Pure max in 56% and 17%, silent sphincter electromyographic activity in 25% and 0%, absent bulbocavernosus reflex in 87% and 56%, absent anal reflex in 100% and 57%, neurogenic motor unit potentials in one patient with cystic form studied and in two of three patients with occult form, respectively.

Spina bifida cystica and occulta present with a wide spectrum of urodynamic abnormalities including upper and lower motoneuron types of bladder and urethral dysfunction. Careful uroneurological assessment and spinal magnetic resonance imaging are important for diagnosing young adult patients with spina bifida occulta because they may present with urinary symptoms as the sole initial complaint and have no other obvious neurological abnormalities.