Functional movement disorders.

Functional movement disorders (FMD) represent a complex and disabling entity characterized by a broad range of clinical symptoms not explained by a classical neurological disease. In 2013, the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) added a clinical criterion based on incongruence and inconsistency, supported by recent literature highlighting the role of "positive clinical signs". These clinical signs allow a "rule-in" procedure in making a diagnosis of FMD so that the diagnosis is no longer a "rule-out" or "by default" diagnosis made after exclusion of other neurological conditions. This review summarizes current evidence on common clinical features and highlights bedside signs in FMD, such as tremor, dystonia, myoclonus and parkinsonism. Tics, chorea and hemiballism are also briefly discussed.