James Watson Kernohan (1896–1981)

Renaut Corpuscles or Peripheral Nerve Infarcts? A Historical Overview

Renaut corpuscles are cylindrical hyaline structures that arise from the peripheral nerve perineurium and project into the endoneurium. Despite their earlier accurate description in the French and German literature, Kernohan and Woltman (1938) reported very similar structures as “nerve infarcts” in a case series of vasculitic neuropathy. Krücke (1955) deserves credit for discovering this error and further explaining how peripheral nerves react differently (from brain parenchyma) to ischemia. We tried to elucidate the reason why Kernohan and Woltman, and others, made this scientific error by describing the historical evolution of our understanding of the structure and function of Renaut corpuscles.

From the notch to a glioma grading system: the neurological contributions of James Watson Kernohan

During his lifetime and a career spanning 42 years, James Watson Kernohan made numerous contributions to neuropathology, neurology, and neurosurgery. One of these, the phenomenon of ipsilateral, false localizing signs caused by compression of the contralateral cerebral peduncle against the tentorial edge, has widely become known as "Kernohan's notch" and continues to bear his name. The other is a grading system for gliomas from a neurosurgical viewpoint that continues to be relevant for grading of glial tumors 60 years after its introduction. In this paper, the authors analyze these two major contributions in detail within the context of Kernohan's career and explore how they contributed to the development of neurosurgical procedures.

Henry Woltman (1889-1964): pioneering American neurologist

Henry Woltman became the first neurologist at the Mayo Clinic in Rochester, Minnesota at a time when there were few practitioners working full-time in this field in North America. The remarkable growth in the neurology section at Mayo mirrored the expansion that occurred in the Mayo Clinic in the early 20th century. His leadership was instrumental in establishing neurology as a viable specialty, distinct from psychiatry and aligned more closely with internal medicine. The distinctive features he instituted included an original scoring and notation system, and a close collaboration with neurosurgery. He is also remembered for Woltman's sign, the finding of slow relaxation of the muscle when the tendon reflex is elicited in hypothyroidism.