Mirror movements in neurology
- Correspondence to: Dr S F Farmer National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK; s.farmerion.ucl.ac.uk
There is a high prevalence of mirror movements in patients with asymmetric parkinsonism
Examination of patients for the presence or absence of mirror movements does not normally form part of a routine neurological investigation nor is this simple part of the motor examination normally taught to medical students and trainee neurologists. The examination requires the examiner only to observe both hands during voluntary fine finger movements of each hand in turn; for example, sequentially pressing each finger against the thumb of one hand whilst the other hand is relaxed. Mirroring occurs when there are visible involuntary movements of the “relaxed” hand that appear to replicate the timing and type of movement being carried out by the voluntarily activated hand.
Mirror movements occur during normal motor development and may reflect children’s inability to suppress the activity of the ipsilateral motor cortex during attempted unilateral activation, possibly due to immaturity of transcallosal inhibition.1 Mirror movements are common at the age of 4 years, …
