MIRROR MOVEMENTS: AN UNDERESTIMATED CLINICAL SIGN

Abstract

Mirror movements (MM) are involuntary movements on one side of the body which mimic voluntary movements of the corresponding side. The MM can be observed in normal individuals, in congenital disorders and in diseases of the central nervous system. The Woods and Teuber scale is widely used for the evaluation of the MM. The pathogenetic mechanism of the MM is not the same in all the diseases; it reflects dysfunction of a network that comprises the primary motor cortex, the supplementary motor area, the dorsal premotor cortex, basal ganglia, and communication between the respective centers, mainly through the corpus callosum. Three genes, involved in the development of the motor system of the brain, have been implicated in the rare familiar disorder of isolated congenital MM with autosomal inheritance. MM may occur in other congenital disorders together with additional symptomatology. Furthermore MM can be found in neurodegenerative diseases of the CNS, in cerebrovascular disease, in cranio-vertebral anomalies, in epilepsy and in cerebral palsy. MM is a sign that should be looked for in the neurological examination and further research concerning their pathogenesis will provide useful information for the mechanism of bimanual movements.