Intention tremor rated according to different finger-to-nose test protocols: a survey.

OBJECTIVES

To investigate the dependence of intention tremor rating scores on different finger-to-nose test (FNT) protocols, varying in arm position and the time the finger has to be kept on the nose, and to examine their relevance to function.

DESIGN

Observational survey. Video recordings were made while patients performed the FNTs and functional tasks such as pouring water.

SETTING

Three European rehabilitation centers in Belgium, Finland, and England.

PARTICIPANTS

Twenty-six multiple sclerosis patients with intention tremor (avg age, 44.1y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Six examiners rated the degree of intention tremor by using the Fahn Tremor Rating Scale.

RESULTS

Interrater reliability for rating intention tremor during the FNTs was high (kappa=.65-.74). Both the required arm position and time constraints affected the magnitude of intention tremor rating scores (mean rank, 2.27-2.95) and their functional relevance (rho=.70-.84). Intention tremor was scored the highest when the arm was lifted to 90 degrees of abduction at the shoulder and the subject was required to stabilize the finger on the nose. However, its functional relevance was lower compared with a more "functionally" executed FNT.

CONCLUSIONS

The rating of intention tremor during the FNT depends on test instructions. A standardized protocol is needed.