INTRODUCTION

Path integration is impaired in prodromal and preclinical sporadic Alzheimer's disease (AD). To determine the timing of PI deficits in AD relative to other cognitive impairments (e.g. episodic memory) we tested the Colombian PSEN1 E280A kindred with autosomal dominant AD. We hypothesized that PI would be impaired in gene carriers prior to symptom onset and before, or at similar time, to deficits in other cognitive tests.

METHODS

188 cognitively unimpaired (MMSE > 24 and FAST < 3) participants, 18–53 years. 92 PSEN1 E280A carriers, 96 non-carriers (Fig. A).
Each participant completed:
•an immersive virtual reality triangle completion task (TCT) to assess path integration1 (fig. B)
•a comprehensive neuropsychological battery (fig. C)
Bootstrapped 6-Year Age-windows
•Identified the earliest overlapping 6-year window showing a carrier - non-carrier difference
•Used 1,000 PSEN1 bootstrap resamples within group
•Retained only windows FDR-significant in ≥80% of resamples

DISCUSSIONS