The purpose of this study is to investigate the potential of using mirror box therapy as a therapeutic technique amongst patients with functional movement disorders. It is hypothesized that a brief, single, in-office mirror therapy session will lead to a noticeable decrease in FMD-related involuntary movements.

Patients diagnosed with Functional Movement Disorder presenting with a unilateral or asymmetrical bilateral hand tremor will be asked to participate in a series of hand exercises with and without a mirror box. The severity of the tremor will be rated subjectively by the subject and objectively by the neurologist after hand exercises with and without the mirror box.

Inclusion Criteria:

1. Patients diagnosed with functional movement disorder by a fellowship trained movement disorders neurologist, presenting predominantly with unilateral or asymmetrical bilateral involuntary movement in the upper extremity
2. In patients with bilateral involuntary movements, the symptoms in one arm must be minimal

Exclusion Criteria:

1. Patients with moderate to severe involuntary movement in both arms
2. Significant cognitive impairment that prevents proper informed consent
3. Severe involuntary movement that interferes with the use of the apparatus
4. Patients with hemiparesis or the loss of one arm due to various reasons (e.g. amputations, birth defects, etc.

Patients diagnosed with functional movement disorder (functional tremor) by a fellowship trained movement disorders neurologist