Facial Expression of Anger and Self-Reported Anger in Patients With Functional Neurological Disorder

Little is known about the way patients with FND express anger and to what extent self-reported anger differs from facially expressed anger. This study investigates whether patients with FND differ from healthy controls in facial anger expression and self-reported anger in response to anger-provoking situations. It also investigates the extent to which there is a mismatch in these responses. In addition, this study explores patients' ability to intentionally express emotions.

This case-control study is based on the EMIN-FND study (OnderzoekMetMensen.nl registration identifier: NL8004). In this study, video recordings of participants' faces were made during an anger recall task and analyzed for facial anger expression using FaceReader software. Participants also reported how much anger they felt during the task. The extent of mismatch was calculated using the z -scores of the self-reported anger and facially expressed anger. The ability to intentionally express facial emotions was examined by analyzing 5-second expression periods.

Data of 66 patients with FND [mean age=42.3 (SD=16.3) y, 68.2% women] and 37 healthy controls [mean age=40.8 (SD=16.4) y, 56.8% women] revealed no differences in facial anger expression ( P =.20), self-reported anger ( P =.80), or mismatch ( P =.19). Patients with FND were less able to intentionally express anger ( U =934.5, z =1.971, P =.049), sadness ( U =745.5, z =3.182, P =.001), and to show a neutral facial expression ( U =880.0, z =2.245, P =.025).

There was no significant difference between facially expressed and self-reported anger between patients with FND versus controls. Intentional expression of an angry, sad, or neutral face was attenuated in patients with FND.