Mitchell's Influence on European Studies of Peripheral Nerve Injuries During World War I

Objective: Describe the influence of S. Weir Mitchell's (1829-1914) work, and in particular his ideas on causalgia, on European physicians who treated peripheral nerve injuries during World War I (WWI). Background: During the American Civil War (1861-1865), Mitchell studied peripheral nerve injuries with colleagues George Read Morehouse and William Williams Keen. Three monographs resulted from this work. All were important landmarks in the evolution of knowledge of peripheral nerve injuries. A subsequent occasion to improve knowledge came in WWI. Methods: The most important European monographs or series on peripheral nerve injuries from WWI were studied with special interest in references to causalgia and Mitchell's works on peripheral nerve injuries. We included works by Tinel, Athanassio-Bénisty, Purves-Stewart & Evans and Carter, Foerster and Oppenheim. Results: Tinel and Athanassio-Bénisty provided the most detailed information on peripheral nerve injuries and causalgia and often referred to Mitchell. Both mentioned a possible sympathetic origin. Athanassio-Bénisty described tremor and other movement disorders in relation to causalgia. Purves-Stewart and Evans mentioned Mitchell and causalgia in the second edition of their book. They advocated the term "thermalgia." Carter, who had access to data of many cases, concentrated his work on causalgia, referring to Mitchell. Foerster provided data of a great number of peripheral nerve injuries, but did not refer to Mitchell. However, he described the symptoms of causalgia cursorily, applying the term Reflexschmerz (reflexpain). Oppenheim was particularly interested in muscle innervation and referred to Mitchell with respect to hypertrichosis and glossy skin. Oppenheim did not use the term causalgia, although he described the syndrome in some of his patients. It wasn't until around 1920 that German physicians devoted significant attention to causalgia and began using the term. Conclusion: Knowledge of peripheral nerve injuries was greatly advanced during and after WWI. Mitchell's influence was mainly found in the French medical literature, where his findings provided the basis for further research on the origin of causalgia. In England, Mitchell and causalgia were also well-known. We found evidence to suggest that some of the English knowledge came from French physicians. German physicians described the symptoms of causalgia, but did not use the term, nor did they refer to Mitchell. This variation in Mitchell's influence by country probably reflects the fact that Mitchell's Injuries of nerves and their consequences was translated into French but not German.     

The Dercum-Muybridge Collaboration and the Study of Pathologic Gaits Using Sequential Photography

In the late 1870s and 1880s, prior to the development of movie cameras or projectors, English-American photographer Eadweard Muybridge (1830–1904) photographed sequential images of people and animals in motion, using arrays of sequentially triggered single-image cameras. In 1885, Philadelphia neurologist Francis Dercum (1856–1931) collaborated with Muybridge at the University of Pennsylvania to photograph sequential images of patients with various neurological disorders involving abnormal movements, and particularly various gait disorders, including both the sensory ataxic gait of tabes dorsalis and various spastic gaits. Dercum used tracings of sequential photographic images to plot trajectories of limbs as a way to characterize and distinguish pathologic gaits. The Dercum-Muybridge collaboration produced the first motion-picture sequences of neurological gait disorders ever filmed. These sequences and the trajectory-based studies that derived from them were a milestone in studies of pathologic gaits.