Mu Rhythm

The “Mu Rhythm was first described by Gastaut et al. in 1952, and is considered a normal variant. The Mu rhythm is similar to the PDR that occurs in the posterior head regions, and it is considered the idling activity of the sensorimotor cortex during wakefulness. Mu appears over the central head regions, has a frequency of 7-11 Hz, can be unilateral or bilateral and is often asynchronous. Mu is attenuated by both thoughts of or actual motor activity of the contralateral extremity. This pattern is twice as common in girls as in boys, and rarely seen in the elderly population.