Hanna, Amgad S.

Since its introduction into medical terminology by Lord Henry Cohen in 1941, the term “neurapraxia” has become established in the neurological and neurosurgical lexicon, although it is often misused or misspelled. It denotes a transient dysfunction of a peripheral nerve, as distinct from axonotmesis and neurotmesis, which describe more significant structural injuries to a peripheral nerve. To expand our understanding of neurapraxia, it is necessary to examine the phenomenon in both temporal and spatial contexts. This study examines neurapraxia in: (A) Time—(1) the origins of the term neurapraxia and (2) the time-course of a neurapraxic injury and its recovery, and (B) Space—(3) the microstructure of a neurapraxic injury and (4) the locations of neurapraxic injuries within the peripheral nervous system. We demonstrate that the term neurapraxia encompasses both a temporal and a spatial definition. In time, it applies to transient peripheral nerve palsy, from which recovery occurs before there is sufficient time for axonal regeneration, typically within a few weeks. In space, there is a histopathological change limited to localized demyelination in nerves lined by epineurium and myelinated by Schwann cells. Nerves distal to the spine qualify as nerves to which the term neurapraxia can apply; however, cranial nerves and spinal nerve roots (including cauda equina) are inconsistent with this owing to the variability in myelinating cells along their course (oligodendroglia proximally, i.e., central glial segment), the absence of an epineurial covering, and exposure to cerebrospinal fluid.

ABSTRACT Nowadays, consent to use donor bodies for medical education and research is obtained from the body donors and their families before the donation. Recently, the International Federation of Associations of Anatomists (IFAA) published guidelines that could restrict the appearance of cadaveric images in commercial anatomical resources such as textbooks and other educational products. These guidelines state that the donor must expressly consent to using such images for this purpose. Cadaveric photos and drawings made from dissections of cadavers have been used in anatomy textbooks and atlases for hundreds of years. They are invaluable for anatomy students and clinical/surgical practitioners. The IFAA guidelines should not restrict the use of those older books; to do so would infringe the rights of those seeking knowledge from these resources. As the images in such textbooks and atlases are anonymized and are used for teaching and research, and the donors and their families are informed about this before the donation, we believe no additional consent is needed. It is impossible to separate educational from “commercial” usage entirely in any situation, e.g., publications from publishers and the use of cadavers in medical schools. Therefore, our best efforts to avoid unethical use of cadaveric images by following traditional consent processes are still needed so that more people will reap the benefits from them. As senior textbook/atlas authors/editors from over 10 countries, we believe that using cadaveric images in anatomy textbooks is appropriate, and no additional consent should be necessary. Such usage falls within the good faith of professionals using these invaluable gifts.

Background: The median nerve anatomy and its clinical presentation are crucial for surgeons to consider avoiding iatrogenic injury and performing effective surgical interventions. Case Description: An atypical presentation of median nerve anatomy proximal to the carpal tunnel was found during cadaveric dissection. The median nerve was located deep to a uniquely double-headed flexor carpi radialis and curved medially around the tendons of the forearm to enter the carpal tunnel superficially. Conclusion: The atypical presentation of median nerve anatomy can assist surgeons in adverse event reduction during surgeries such as carpal tunnel and pronator teres syndrome releases.