Acute VI nerve palsy in a 4 year-old girl with Chiari I malformation and pontomedullary extension of syringomyelia: case report and review of the literature.

We report the case of a previously healthy 4 year-old African American female who presented to the emergency department with acute onset of unilateral abducens nerve palsy and torticollis. Within 12 h of presentation, the patient's symptoms progressed to include ipsilateral facial nerve palsy and gait ataxia. On exam, the patient demonstrated right cranial nerve VI and VII palsies, ataxic gait with left lateropulsion, spasticity of bilateral lower extremities with clonus, and the presence of bilateral Babinski sign. MRI of the brain and spinal cord revealed severe Chiari I malformation with associated extensive holochord syringomyelia and syringobulbia. The patient underwent successful surgical decompression 72 h after initial presentation. We review the literature on Chiari malformations and syringomyelia, including epidemiology, presentation and neurological manifestations, and treatment recommendations. As our patient had a very acute presentation, we additionally review the previously reported cases of acute and atypical presentation of patients with Chiari I malformation and syringomyelia. The aim of this report is to make practitioners aware of the acuteness with which children with Chiari malformation type I with syringomyelia and syringobulbia can present.