Movement Disorders | 2019
Functional movement disorders in U.S. veterans: Psychiatric comorbidity and health care utilization
Abstract
There has been considerable debate about the role of psychological factors in the etiology, diagnosis, and treatment of functional movement disorders (FMDs). Recent consensus has settled on the term functional over “psychogenic” and highlighted the importance of phenotype-specific diagnosis of FMD without the required presence of psychopathology. However, psychiatric disturbances remain important as risk factors for FMD. The associations between psychiatric factors and FMD have not been examined specifically in U.S. military veterans, a group with high rates of trauma exposure and psychiatric comorbidity. Studies of another functional neurological disorder, psychogenic nonepileptic seizures, in U.S. veterans found a diagnosis of posttraumatic stress disorder to be predictive of psychogenic nonepileptic seizures. Importantly, the same group also reported greater health care utilization (HCU) among veterans with psychogenic nonepileptic seizures when compared with those with epileptic seizures. Here we present a preliminary examination of the clinical features of FMD including associated psychiatric comorbidity and HCU data from a U.S. Veterans Affairs Health Care System movement disorders clinic. We reviewed records of all veterans seen as new consultations in the Portland a U.S. Veterans Administration Health Care System Movement Disorders Clinic during a 24-month period. Record review was limited to those available within the Veterans Affairs electronic medical record system, and only psychiatric diagnoses made by formal mental health assessment were included. Veterans with FMD (FMDv) were compared with a group of randomly selected veterans diagnosed with an “organic” movement disorder (OMDv) at initial movement disorders clinic evaluations during the same time period. For both groups, nationwide Veterans Affairs HCU data was obtained for the 3-year period prior to the movement disorder consult using the Corporate Data Warehouse. Of 693 consecutive veterans evaluated, 3.6% (n = 25) had FMD. The most frequently observed presenting movement type in FMDv was tremor (n = 16, 64%), followed by myoclonus (n = 4, 16%), dystonia (n = 3, 12%), and gait disturbance (n = 2, 8%). Both FMDv and OMDv were 90% male, which is typical of VA samples. FMDv were significantly younger than those in the comparison group (55.0 vs 70.4, P = .0009). Psychiatric disorder was significantly more common in FMDv when compared with OMDv (76% vs 40%, P = .001), and FMDv had a greater total number of psychiatric diagnoses on average (1.5 vs 0.6, P = .006), although no individual diagnostic category significantly differentiated the 2 groups (Table 1). FMDv used more health care resources when compared with OMDv (Table 1). This examination of FMD characteristics in US veterans reveals younger patients with higher rates of psychiatric comorbidity and increased HCU when compared with veterans presenting with OMD. FMD prevalence and phenomenology was similar to that seen in civilian movement disorder FMD samples. Although a history of psychiatric disturbance is not indicated for FMD diagnosis, studying FMD in veterans specifically may offer important insights into the relationship between psychological factors such as combat-related trauma or other trauma and FMD. HCU is an indicator of overall health status (as well as costs), and it is impressive that FMDv used more resources than OMDv, a significantly older group of patients, many of whom were thought to have a neurodegenerative illness (eg, Parkinson’s disease) at movement disorder assessment. As our study is limited by retrospective design, further work is needed to examine psychiatric correlates of FMD in veteran populations; the relationship between psychiatric factors, FMD, and HCU; and how psychiatric disorders and their treatments might modulate prognosis and response to treating FMD.