First documented clinical account of brachial plexus palsy from the 12th century

Although literary depiction of brachial plexus injury can be traced to Homer's Iliad, there is a scientific consensus that the first clinical description of brachial plexus palsy was not documented until the British physician Smellie reported it in the 18th century. However, the authors' recent review of the Syriac Book of Medicines (12th century) has uncovered a much earlier clinical documentation.

For this historical vignette, the authors reviewed the historical and anatomical literature regarding earlier descriptions of brachial plexus anatomy and pathology, including a thorough analysis of the Syriac Book of Medicines (attributed to an unknown Syriac physician in the Middle Ages) and Galen's On Anatomical Procedures and On the Usefulness of the Parts of the Body.

Building on the galenic tradition with reference to independent dissections, the Syriac physician discussed nervous system anatomy and the clinical localization of neurological injuries. He described a patient who, after initial pulmonary symptoms, developed upper-extremity weakness more pronounced in the proximal muscles. His anatomical correlation placed the injury "where the nerves issue from the first and second muscles between the ribs" (scalene muscles), are "mixed," and "spread through many parts." The patient's presentation and recovery raise the possibility of Parsonage-Turner syndrome. The anatomical description of the brachial plexus is in line with Galen's earlier account and step-by-step surgical exposure, which the authors reviewed. They also examined Ibn Ilyas' drawing of the brachial plexus, which is believed to be a copy of the earliest artistic representation of the plexus.

Whereas the Middle Ages were seen as a period of scientific stagnation from a Western perspective, Galen's teachings continued to thrive and develop in the East. Syriac physicians were professional translators, clinicians, and anatomists. There is evidence that brachial plexus palsy was documented in the Syriac Book of Medicines 6 centuries before Smellie.