Jules Tinel (1879-1952) and Paul Hoffmann (1884-1962)

Abstract

A 45-year-old female presented with a 2-month history of numbness and tingling in her right hand. The symptoms, which were localized to the fingers, occurred throughout the day and wakened the patient at night. She reported that the symptoms were partially relieved by “shaking” her hand. The patient also reported weakness in her right hand, causing her difficulty in carrying her briefcase. Physical examination revealed asymmetric weakness on thumb adduction with evidence of thenar atrophy. Sensation to two-point discrimination testing was impaired in the first and second fingers of the patient’s right hand. She had a negative Phalen sign but a positive Hoffmann-Tinel sign. Jules Tinel, a French neurologist, and Paul Hoffmann, a German physiologist, served as physicians for opposing sides during the First World War and both described the findings of the sign that bears their names. Hoffmann further described the sign as a diagnostic maneuver used to localize levels of nerve damage and assess the course and adequacy of nerve regeneration after peripheral nerve injury. In modern medical practice the Hoffmann-Tinel sign, also referred to as Tinel’s sign, is most commonly used with suspected cases of entrapment neuropathies affecting either the median nerve within the carpal tunnel or the ulnar nerve in the postcondylar groove (table 1 ▶). The Tinel sign is elicited in suspected cases of carpal tunnel syndrome by tapping or percussing on the distal wrist crease over the median nerve (figure 1 ▶). A positive sign is defined as the occurrence of paresthesias in the distribution of the median nerve in the hand. Classic, probable and unlikely patterns of carpal tunnel within the hand are identified depending upon the number of digits involved (e.g., at least two digits in classic carpal tunnel, only one digit in probable carpal tunnel).1 Hoffmann recommended that when testing for the Hoffmann-Tinel sign, light pressure should be applied, since increased pressure may elicit a positive sign even in patients with a normal nerve.2 Thus, in the assessment of carpal tunnel syndrome, a greater percussion force results in improved sensitivity but lower specificity of the Hoffmann-Tinel sign.3 Figure 1. Hoffmann-Tinel sign is elicited by percussing using the extended index finger (A) or blunt end of a reflex hammer (B) over median nerve. Table 1. Application of the Tinel sign. Dr. Paul Hoffmann described the sign in March of 1915 in On a Method of Evaluating the Success of a Nerve Suture.2,4 Several months later in October 1915, Dr. Jules Tinel published his work on the sign in The Sign of Tingling in Lesions of Peripheral Nerves.5 Interestingly, neither Hoffmann nor Tinel was aware of the other’s publication, possibly a result of the wartime blockade of international communication.6 Ironically, various authors have proposed that neither physician should be credited with the original description of the phenomenon.7 In 1909, Trotter and Davies discussed their findings that sensations elicited distal to the point of nerve resection are referred to the area or point of nerve resection. Unlike Hoffmann and Tinel, however, Trotter and Davies failed to comment on the clinical relevance of their observation.8 Why the sign has classically been referred to as Tinel’s sign and not Trotter, Davies or Hoffmann’s sign is not entirely clear. Perhaps it is because Tinel had greater notoriety than Hoffmann, and his description was more thoroughly documented. Tinel’s paper was also published in a widely circulated journal and was engrained within the writings of surgical and medical textbooks published in the earlier part of the century.2,6 It can also be postulated that Tinel had the good fortune of being on the victorious side during the war, and thus, his publication may have been perceived as being more prestigious by the medical community.6,7,9