High Median Nerve Paralysis: Is the Hand of Benediction or Preacher’s Hand A Correct Sign?

Abstract

Background: High median nerve injuries are commonly presented in textbooks as adopting the typical posture of hand of benediction or preacher’s hand. This study aimed to show that the hand of benediction or preacher’s hand is incorrectly associated with a high median nerve paralysis. Methods: A retrospective review of four cases with a high median nerve injury is presented. Diagnosis of a high median nerve injury was performed by means of intraoperative findings, electrodiagnostic studies, or ultrasound imaging. None of the patients presented in this study had a hand of benediction on physical examination despite the presence of a high median nerve lesion. Results: All four patients with high median nerve injuries showed a similar hand posture when attempting to make a fist. Firstly, the index finger still flexed at the metacarpophalangeal joint because of the ulnar innervated interossei muscles. Secondly the thumb is completely abducted at the carpometocarpal joint and extended at the interphalangeal joint. Lastly, middle finger flexion is possible due to dual innervation of its flexor digitorum profundus by the ulnar nerve as well as due to the quadriga phenomenon. Conclusions: The clinical appearance of a high median nerve palsy is different from the classical hand of benediction or preacher’s hand posture pointing finger. We have shown that this incorrect association can result in delayed referral of patients with high median nerve injuries.