[Henry Head (1861-1940) and his importance for neurology]

Nowadays, Henry Head is best known for his Head zones. The concept was understood very differently by Head in comparison to what current medical books falsely describe them to be. In reality, there is no direct relationship between one particular skin zone and one single organ. It is certain that the drawings considered depictions of the Head zones in today's medical textbooks were actually not created by Head. From a neurological point of view, Head is important for two reasons: his self-experiment in 1909 to damage one of his own peripheral nerves followed by regeneration was heroic. It has helped generations of neurologists to have a better understanding of the pathophysiology of peripheral nerve damage and thus make a better assessment of the prognosis of such injuries. Head's second contribution pertains to the radicular organization at the level of the spinal cord. The pathophysiology of herpes zoster radiculitis enabled him to develop the concept of the dermatomes on the basis of preliminary work around 1900. Henry Head's contribution was the systematic compilation of the existing publications of the time and amendment of his own cases. As he was the most important neurologist at that time, at least in the English speaking world, and was well connected with people in the German neurology community, it was probably easy for him to make his dermatome maps well known. In retrospect, Head was less successful in neuropsychology with holistic concepts for higher cognitive functions which were in vogue during his lifetime. His late work on aphasia is now considered refuted. Head's criticism of the strict localization was well in syncronization with the zeitgeist of the early twentieth century. Establishing the fact that Broca's aphasia and Wernicke's aphasia are not easily diagnostically distinguishable from each other was more an achievement of subsequent generations of neurologists and neuropsychologists as well as technical advances.