10.: Functional neurological disorders in outpatient practice: An Australian cohort

Functional neurological disorders (FND) are a common presentation in neurology practice. They are a very diverse group of disorders with an incidence approaching 30% in some studies. Despite this, little is known about their genesis and outcome. Case definition and psychiatric overlap is also a factor in creating difficulties for further research. The aim of this study was to determine the incidence and outcome of functional disorders in Australian neurology practice. All patients presenting to a single general outpatient neurology service were evaluated over a 15 month period. Patients with functional illness were identified and categorized based on their presenting symptoms. Demographic data were collected and compared to other neurological presentations. Outcome was assessed where possible at routine follow-up. Of 884 patients, 137 (15%) had a diagnosis of a FND. FND were the third most common presentation overall. FND patients had a significantly lower average age (45 versus 56 years, p < 0.0001) and higher proportion of females (76% versus 56%, p < 0.0001) compared to other neurology patients. A higher rate of major psychiatric comorbidity was also found (11% versus 4%, p < 0.01). Sensory symptoms were the most common manifestation, followed by paresis and non-epileptic seizures. Outcome information was available for 50% of FND patients at an average of 3 months of follow-up. Forty-four percent had some improvement in their symptoms and the other 56% had static or worsening symptoms. This study confirms the high incidence of functional disorders in outpatient neurology practice. These disorders were the third most common neurological presentation. A substantial proportion of patients have early improvement in their symptoms.