Unilateral all ulnar hand including sensory without forearm communication.

The prevalence of "ulnar hand" is extremely rare. In the ulnar hand, all the intrinsic hand muscles are innervated exclusively by the ulnar nerve; however, all reported cases have been limited to ulnar motor innervation. We present a case that demonstrated exclusive unilateral ulnar motor and sensory innervation. Although the all ulnar hand is extremely rare, an awareness of this variation is essential for the correct interpretation of the findings on electrodiagnostic examination.