Evaluating the relationship between response to an olfactory stress test and level of cognitive decline in older adults.

The study is designed to determine the extent to which olfactory testing, performed conventionally, and also the change in olfaction following an intranasal anticholinergic challenge, is associated with cognitive decline. Study participants returning to Phase 2 of the study will be assessed for cognitive change now that 4 years has passed. Participants will receive two mail out surveys used in Phase 1. Participants who are eligible will participate in two visits. Visit 1 (duration 3-3.5 hours): Like Phase 1, participants will complete the Audio Recorded Cognitive Screen (ARCS), complete a series of questionnaires regarding medical history and cognition, and complete two smell tests. Smell Test 1: University of Pennsylvania Smell Identification Test (UPSIT). Participants are asked to identify odours from a scratch and sniff booklet. Twenty items of the UPSIT will be administered prior to atropine being administered. After 45 minutes we will test with the remaining 20 items of the UPSIT. Smell Test 2 (following Smell Test 1): Sniffin sticks are used as a test of nasal chemosensory performance that is based on pen-like odour-dispensing devices. Participants will be presented with 16 pens at an interval of 30 seconds. Each participant is provided with a sheet of paper which describes 16 lists with 4 items each. Participants have to identify the item that best describes the presented odour. Test repeated at 45 minute interval, following atropine administration. Upon completion participants will be asked to complete a sleep diary for 1 week and wear an accelerometer during that period. Visit 2 (within 7 days of visit 1, duration 1.5 hours): Participants will attend a clinic appointment for a Neuropsychological Test Battery (NTB). The NTB is comprised of the following tests: California Verbal Learning Test (CVLT), WMS IV Visual Reproduction Test, WAIS IV Block Design, Similarities and Digit Span, WAIS IV Symbol Search & Coding, Colour Word Interference Task and the test of Premorbid Functioning. The major implication and novelty of this study lies in the new technique for administering 1% atropine during Visit 1. . This involves using a soft narrow tube attached to a syringe that the study participant gently inserts into their left nostril until they feel the end touching the inside of their nose, which occurs as it reaches the olfactory cleft, where we wish to deposit atropine. The participant then squirts the syringe to deposit a measured dose (0.05 ml) of the atropine.