Scoliosis associated with HGPPS syndrome: What do we know?

Horizontal gaze palsy with progressive scoliosis (HGPPS) syndrome is a rare genetic abnormality causing cranial dysinnervation manifesting as absence of conjugate lateral eye movements, nystagmus, and scoliosis. While the genetics, imaging abnormalities, and ocular manifestations have been well described in literature, the spinal deformity has not been addressed adequately. An 11-year-old girl presented with progressive thoracic scoliosis who on evaluation was detected to have all the features of HGPPS syndrome. The patient underwent posterior correction of scoliosis uneventfully. A thorough literature search was performed to understand the descriptors of spinal deformity and its surgery in HGPPS syndrome. The spinal deformity in HGPPS resembles adolescent idiopathic scoliosis. Rapidly progressive right thoracic scoliosis was the usual pattern. Surgical and anesthetic considerations during surgery are similar to idiopathic scoliosis. These children tolerate surgery and anesthesia well. Neuromonitoring changes during surgery need to be interpreted correctly in the background of uncrossed sensory and motor tracts.