Journal of Shoulder and Elbow Surgery vol:19 issue:8 pages:e14-e16
Parsonage-Turner syndrome is a well-known clinical entity. One-third of patients present with bilateral involvement of the brachial plexus.6 The motor deficits are primarily clustered in the upper trunk, but the middle or lower trunk may also be involved. We describe an unusual case of bilateral Parsonage-Turner syndrome with unilateral wasting of the left brachialis muscle. Electromyographic (EMG) studies
demonstrated that only the brachialis muscle was affected without involvement of any other muscles of the left brachial plexus.