Meningomyelocele: Arnold-Chiari assoc
Given that CM II is universally associated with myelomeningocele, the first sign is an open neural tube defect. Once born, a symptomatic CM II is the most common cause of death in patients with myelomeningocele who are younger than 2 years of age. They present with respiratory and brainstem findings which should be evaluated urgently. In this age group inspiratory stridor from vocal cord paresis is often the most noticeable sign of brainstem dysfunction. Older children present with spinal cord and cerebellar dysfunction. Signs and symptoms of cervical myelopathy are the hallmark finding in older children, with upper-extremity weakness and spasticity being the most common finding.  The first treatment option to be considered should be cerebrospinal shunt revision because the most common symptom in this population is hydrocephalus or a failed shunt. If this fails, surgical decompression with removal of the lamina of the first and second cervical vertebrae is required. There have been advances in fetal intrauterine myelomeningocele repair but, as of now, intrauterine myelomeningocele repair has not been shown to improve lower extremity motor and sensory function.  However, this technique may reduce the severity of, or completely prevent, the CM II.