Functional Neurological Symptom Disorder in Williams Syndrome: Case Series and Review of Relevant Literature

Abstract

Background: Williams syndrome (WS) is a neurodevelopmental disorder associated with several medical and psychiatric comorbidities.

Objective: To describe the clinical presentation and treatment course of functional neurological symptom disorder (FNSD) in 3 adult patients with WS.

Methods: This report describes the clinical presentation and long-term follow-up of 3 individuals with WS and FNSD who experienced a range of clinical presentations and responses to treatment. The literature on the clinical assessment and treatment of FNSD as it applies to patients with neurodevelopmental disorders is reviewed.

Results: FNSD treatment strategies used in the general population were successfully adapted for these 3 patients. Literature on the diagnosis and treatment of FNSD in patients with neurodevelopmental disorders is lacking.

Conclusions: FNSD may be more common in individuals with WS than previously appreciated, and future studies describing the prevalence, clinical presentation, risk factors, and treatment of FNSD in WS are needed.

Keywords: Williams syndrome; case series; conversion disorder; functional neurological symptom disorder; pseudoseizure.