RR-PO-1903

Monday 12:30, Palau de Congressos, Exhibition Hall  [Display No. 496]

A FUNCTIONAL MEASURE OF NAVIGATION. Kaldas J, Paquet N, Dannenbaum E, Fung J; School of Physical and Occupational Therapy, McGill University and Jewish Rehabilitation Hospital Research Center; Quebec, Canada PURPOSE: Healthy subjects manifest errors of navigation in the estimation of both distance and direction when they walk with eyes closed towards previously seen targets (Paquet et al., J. Otolaryngol, in press). Our objectives are (1) to develop a test of spatial navigation; (2) to determine test-retest reliability of navigation measures within a 7-day interval in healthy individuals. RELEVANCE: Aging and many neurological conditions lead to navigation disabilities. However, no clinical tool exists to detect and quantify errors of navigation. SUBJECTS: Ten healthy subjects (20-40 y/o) were tested twice in a 7-day interval. METHODS: Subjects side stepped with eyes closed towards targets located 1.25 meters to their right and left, and stopped when they estimated that they were standing in front of the target. Head and body position was recorded in 3-D to determine (1) the total distance traveled (TDT); (2) angular deviation (AD): angle formed between the line joining the initial and end targets and the line joining their two shoulders; (3) area under the trajectory (AUT): area formed in the triangle between the subject’s actual trajectory and the line joining the targets. ANALYSIS: Intraclass correlation coefficients (ICC) were calculated. RESULTS: Mean TDT at test was 1.74 ± 0.20 m and 1.74 ± 0.32 m at retest (ICC = 0.79); mean AD was 6° ± 6° at test and 6° ± 5° at retest (ICC = 0.62); mean AUT was 1.6 ± 0.2 m^2 at test and 1.5 ± 0.3 m^2 at retest (ICC = 0.78). CONCLUSION: A consistent overshooting was found in all healthy subjects during navigation. Our measures of direction errors and deviation yielded good to very good reproducibility in a 7-day period.  We acknowledge the support from  CIHR, CFI, FRSQ, REPAR and Burroughs Wellcome Fund.