Syringo-subarachnoidal shunting to correct unilateral leg deformity in a child with terminal syringomyelia: case report

Abstract

Among cases with terminal syringomyelia, 25% are associated with tethered cord syndrome. As it can be difficult to determine whether the neurological deficits are attributable to a syrinx or to a coexisting occult spinal dysraphism, it is not easy to determine the correct surgical strategy. We report a 19-month-old girl with an underdeveloped right leg and pes varus detected when she was 1 month old; lumbosacral magnetic resonance imaging (MRI) revealed syringomyelia. She developed recurrent urinary tract infections and consulted our department with a diagnosis of congenital neurogenic bladder. She presented with clubbed equine position, wore a short brace on her underdeveloped right leg, and exhibited limping gait due to shortening of the right leg. There was no anal reflex. The skin on her lower back was normal. MRI study showed that the lower end of the conus medullaris existed at the L3/4 level; central-type syringomyelia was recognized in the conus medullaris at the T12/L1-L2/L3 level. Computed tomography myelography detected no trabeculae causing tethering effects or influx of contrast medium into the syrinx. There was no comorbid disease like hydrocephalus or Chiari malformation. We performed syringo-subarachnoidal shunt by L1-L2 hemilaminectomy. Postoperative MRI confirmed shrinkage of the syrinx. One year later, although her perianal sensory loss and bowel and bladder dysfunction remained, her right leg had caught up with the left and at 1 year and 9 months after the procedure there is no discrepancy in her legs and she is able to run without limping.