Is Pseudotumor Cerebri an Unusual Expression of Chiari Syndrome? A Case Report and Review of the Literature.

The Chiari I malformation (CM-I) is a developmental alteration of the posterior cranial fossa (PCF), radiographically defined as the descent of the cerebellar tonsils ≤ 5 mm below the foramen magnum (FM) inside the cervical canal. Headache is the most frequent symptom associated with CM-I. The association of CM-I and neurological symptoms configures with Chiari syndrome. A rare symptom associated with Chiari syndrome is intracranial hypertension syndrome with cephalea and papilloedema-the typical findings of pseudotumor cerebri (PTC). PTC is a syndrome characterized by signs and symptoms of increased intracranial pressure (ICP) in the absence of space-occupying masses and/or obstruction of the ventricular system detectable by neuroimaging. The most common symptoms are headache and visual disturbances. Literature reports that the association between CM-I and PTC has a prevalence of 2-6%. More recently, a prevalence of 11% has been described in a specific subset of obese or overweight female patients between 20 and 40 years old. Here we report the case of a 38-year-old woman who came to our observation with a clinical picture and neuroradiological examinations compatible with both CM-I and PTC. We discuss the clinical case and the significant improvement after surgical occipito-cervical decompression.