Chiari I malformation associated with atlanto-occipital assimilation presenting as orthopnea and cough syncope.

Although it is not uncommon for patients with Chiari I malformations to present with respiratory complaints, cough syncope is a rare presenting symptom. We report an adult patient who had both a Chiari I malformation and atlanto-occipital assimilation, and complained of cough syncope, orthopnea, and central sleep apnea. The patient underwent decompressive craniectomy of the posterior fossa and a cervical level 2 laminectomy. However, due to an initial under-appreciation of the profound narrowing of the foramen magnum as a result of these concomitant pathologies, the patient had continued impaired cerebrospinal fluid flow, leading to a symptomatic pseudomeningocele and required a more extensive decompression that included a cervical level 3 laminectomy as well as a temporary lumbar drain. On 2 year follow-up, he remained asymptomatic.