A Case Report of Headache and Weakness Diagnosed as Functional Neurological Disorder

Cerebral venous sinus thrombosis (CVST) is a rare diagnosis and is estimated at 1.32-1.57 per 100,000 cases. Patients with CVST often present with headache, seizures, focal motor deficits, encephalopathy, or aphasia, and can be fatal in 3%-15% of cases. Newer diagnostic criteria indicate functional neurological disorder (previously known as conversion disorder) as a "rule in" diagnosis that should be given only if patients meet strict criteria.

A 26-year-old woman with a past medical history of depression during pregnancy, anxiety, and migraines, presented to a large emergency department in the United States with headache, unilateral weakness, spastic movement, numbness, and "feeling off." At the time of presentation, she had a Glasgow Coma Scale score of 14 and was approximately 7 weeks postpartum and had resumed oral contraceptives 11 days prior. After a normal head computed tomography scan, she was discharged with a diagnosis of anxiety reaction and headache, with question of possible conversion disorder. The patient returned the next morning with worsening weakness and inability to walk. Given that she was only intermittently following commands, she was admitted for seizure monitoring, with particular concern for psychogenic nonepileptic seizures. A magnetic resonance imaging scan ordered by the admitting hospitalist indicated left thalamic infarct secondary to cerebral venous thrombosis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: CVST should be considered on the differential for premenopausal women presenting with headache, altered mental status, and focal neurological deficits. The diagnosis of functional neurological disorder was previously thought of as a diagnosis of exclusion, however, it is now a diagnosis of inclusion using specific positive findings.