To assess inpatient and emergency department (ED) utilization and costs in functional neurological disorders (FND) in adults and children.

Although FND represents up to 31% of adult neurology outpatient visits, 20% of movement disorders clinics, and 9% of neurology inpatient admissions and are a common source of ED presentations, cost and healthcare utilization data have not been quantified.

We used large federal healthcare databases to assess 1) adult (age>18) inpatient hospitalizations (2008-2017), 2) pediatric (age 5-17) hospitalizations (2003-2016), and 3) adult/pediatric ED evaluations (2008-2017). We used ICD-9-CM codes 300.11 “conversion disorder” or 306.0 “musculoskeletal malfunction arising from mental factors” and ICD-10-CM codes for conversion disorder (F.44.4-F44.7) to conservatively define FND and compared with other high-utilizing neurological diagnoses.

Adult/pediatric FND inpatient admissions were more frequently emergent, had shorter hospital stays but higher rates of laboratory and imaging investigations than other neurological disorders (p<0.0001). FND had unexpectedly low inpatient psychiatric consultation rates and physical/occupational/speech therapy evaluations. Total annual charges (2017 dollars) were used as a proxy for costs. Adult 2017 FND inpatient charges were $1.1 billion, comparable with anterior horn cell disease; pediatric 2012 FND inpatient charges were $75 million, comparable with neuro-inflammatory diseases. In 2017, adult and pediatric ED charges were $163 million, comparable with refractory epilepsy. Total and per-admission costs for FND from 2008-2017 rose at a higher rate than other neurological disorders.

The over $1.2 billion and rising annual charges for inpatient and ED FND care is comparable with other investigation-intensive and pharmacologically-demanding neurological disorders but with low anticipated yields given the low use of necessary psychiatric and rehabilitative treatments. These findings reflect a conservative estimate and do not include outpatient costs, underscoring the high levels of resource use for this condition and the need for increases in funding for clinical care and research on FND.