Research on the most common hand and arm nerve entrapment disorder carpal tunnel syndrome (CTS) is conducted in collaboration with the departments of Occupational Medicine at Aarhus University Hospital and Hospital Unit West. The collaboration allows for a link between the results of electrophysiological studies and data on occupational exposures.

CTS causes nocturnal numbness and pain in the median nerve innervated fingers, and in severe cases also atrophy of the thenar region. An incidence of 2-3% per year has been reported in working populations, and the incidence is 2-5 times higher among workers exposed to hand intensive work (repetition, force, awkward postures, and hand-arm vibration).

Three research studies are conducted at our department:

The first study assesses which occupational exposures result in CTS and CTS-like symptoms comparing three groups: 1) Patients with CTS verified with nerve conduction studies, 2) Patients with CTS-like symptoms with normal nerve conduction studies, and 3) A healthy control group. The methodology used in the study is a triple case-referent study design together with a job exposure matrix based on experts’ ratings - a methodology that has been developed by the group in a previous project on ulnar nerve entrapment.

The second study examines the prognosis of CTS related to CTS-like symptoms based on 500 patients. A baseline standardised clinical examination, a baseline questionnaire, and electrophysiological data are compared with a follow-up questionnaire 9-12 months later.

A third study investigates the impact of seasonal hand intensive work on nerve conduction in the median and ulnar nerves. The study is based on mink skinners in Denmark. Serial nerve conduction studies are performed on mink skinners before, during, and after the mink skinning season, and the results are related to symptoms of CTS and to exposure measures.

It is expected that the projects will provide extended knowledge on CTS as a work related disorder including knowledge that can be used in the prevention of this common disorder.

Contact

Birger Johnsen, Associate Professor, MD, PhD birgjohn@rm.dk
Anders Fuglsang-Frederiksen, Professor, MD, DMSc andefugl@rm.dk