Functional movement disorders (FMD) are conditions where people experience unusual movements or difficulties with walking, not caused by a specific brain or nerve injury but related to how the brain controls movements. Functional movement disorders are common in clinical practice and can lead to significant disability and healthcare costs.
A key feature of FMD is a problem with self-agency-the feeling that we are in control of our own movements. Many patients with FMD feel that their abnormal movements happen without their control. Sensory attenuation is closely linked to self-agency. It's the brain's way of reducing the intensity of sensations caused by our own movements. For example, you can't tickle yourself because your brain knows it's your own action. In people with FMD, this process doesn't work properly. As a result, they might feel their movements are involuntary.
Previous research shows that sensory attenuation is reduced in FMD, but the studies so far have been small. This study will investigate sensory attenuation in a larger group of FMD patients and compare it with healthy individuals. The goal is to see if reduced sensory attenuation could be used as a marker to measure the severity of FMD.