Early foramen magnum decompression in a 22-month-old child with Morquio Syndrome: Case report and literature review

Abstract

Introduction: Morquio syndrome is a rare form of mucopolysaccharidosis (Type IV-A) where intelligence is unaffected, skeletal anomalies are frequent and characteristic due to deposition of keratin sulphate in the skeletal system. Craniovertebral junction anomalies in these patients are frequently the cause of morbidity and mortality. Case Presentation: A 22-month-old child presented with weakness of all four limbs following a trivial fall at home. There was also a history of head tilt to the left for 6 months. On examination, the child was active and alert. He had a flattened nasal bridge, sharp peg teeth and pectus carinatum. Neurological examination showed gross spastic quadriparesis with features suggestive of high cervical myelopathy.CT scan of the cervical spine showed atlantoaxial subluxation, dens hypoplasia and deficient posterior arch of atlas. Magnetic resonance imaging showed severe cervico-medullary compression at C1-2 with antero-posterior canal dimension of 3 mm with myelopathy and non-ossified apex of dens. Radiography of the skeletal system was consistent with the diagnosis of Morquio syndrome. Given the symptomatic cord compression and atlantoaxial subluxation, the senior author (KG) performed a foramen magnum decompression with occipitocervical bony fusion using autologous rib grafts, supplemented by a Minerva jacket for 3 months. Post-operatively the child had complete resolution of spasticity along with normal power of all four limbs. Conclusion: Early definitive management of cord compression is crucial to avoid the development of permanent deficits like quadriplegia, respiratory arrest or sudden death after a trivial fall.

Keywords

• Atlantoaxial instability
• Cervical myelopathy
• Craniovertebral junction anomaly
• Early Intervention
• Morquio syndrome
• Pediatric spine