Reliability and responsiveness of a graduated tuning fork in immune mediated polyneuropathies
- I S J Merkiesa,
- P I M Schmitzb,
- F G A van der Mechéa,
- P A van Doorn for the Inflammatory Neuropathy Cause and Treatment (INCAT) Groupa
- aDepartment of Neurology, Daniel den Hoed Cancer Centre, University Hospital Rotterdam/Erasmus University, Dr Molewaterplein 40, 3015 GD, Rotterdam, The Netherlands , bDepartment of Statistics
- Dr I S J Merkies email merkies{at}neur.azr.nl
- Received 26 August 1999
- Revised 14 December 1999
- Accepted 5 January 2000
Abstract
The interobserver and intraobserver reliability of the Rydel-Seiffer (RS) graduated tuning fork was evaluated in 113 patients with a clinically stable immune mediated polyneuropathy (83 patients who had had Guillain-Barré syndrome (GBS) in the past, 22 with a chronic inflammatory demyelinating polyneuropathy (CIDP), and eight with a polyneuropathy associated with a gammopathy of undetermined significance). Additionally, the responsiveness of this instrument was serially investigated in 20 patients with recently diagnosed GBS or CIDP and changing clinical conditions. The measures were done in triplicate at eight different locations in the limbs and the values were compared with the recently published vibration threshold reference values. Good interobserver and intraobserver agreements (quadratic weighted κ=0.67–0.98) and high responsiveness values (standardised response mean scores>0.8) were demonstrated for the RS tuning fork. These results provide, in addition to literature findings, further evidence for incorporation of this easily applicable instrument in routine neurological examination.
