Post-operative Horner's Syndrome: A Rare Complication Following Posterior Scoliosis Surgery in a Patient With Syringomyelia.

Horner's syndrome following posterior spinal instrumentation for scoliosis has been rarely reported. We describe the case of a 15-year-old male who presented with right-sided ptosis, miosis, and anhidrosis after scoliosis correction. This is the first reported case of first-order Horner's syndrome developing after scoliosis repair via posterior fixation in a patient known to have asymptomatic syringomyelia. The impression was that Horner's syndrome developed secondary to increased traction of the syringomyelia after scoliosis repair. This is significant as a diagnosis of Horner's syndrome can be distressing to patients and chronic cases cause cosmetic defects that might require surgical correction. We suggest that similar patients should be warned pre-operatively given the psychological distress associated with chronic Horner's syndrome. This case also illustrates the importance of an appropriate workup to rule out other sinister pathologies that can cause Horner's syndrome.