Olfactory testing in consecutive patients referred with suspected dementia.

BACKGROUND: Alzheimer's disease (AD) is the most common cause of dementia and early and accurate diagnosis is important. Olfactory dysfunction is an early sign of AD. The contribution by test of olfactory function has been surveyed in AD vs a line of conditions but remains to be settled in the workup of unselected patients referred with suspected dementia. METHODS: We performed a two-step investigation: first, a comparative study of healthy controls and probable AD patients to test the applicability of the chosen scents (cuisine study); second, a study of consecutive patients referred to our geriatric outpatient clinic for suspected dementia with the investigating personnel blinded to the results of the Olfactory Test (blinded study). RESULTS: The sum of scents detected discriminated patients with probable AD from controls in the cuisine study (n = 40; p < 0.001; area under ROC curve 0.94). In the blinded study (n = 50) the diagnosis was probable AD in 48%, minimal cognitive impairment in 24%, vascular dementia in 8%, alcohol induced impairment in 12%, depression in 4%, and Parkinson's disease and Lewy body dementia in 2%. Area under the ROC-curve was 0.67. The odds ratio for probable AD with 2+ smell errors was 12 (95%-CI: 1.3-101; p = 0.026 (reference 0-1 smell errors)) age adjusted. None in the AD group had zero smell errors (Negative Predictive Value 100%). CONCLUSION: Olfactory testing may support to dismiss the diagnosis of probable AD in the workup of a mixed group of patients referred with cognitive impairment. Still, it had a low sensitivity for probable AD.

Intrarater reproducibility and validity of Nintendo Wii balance testing in community-dwelling older adults.

The aims of the current study were to examine the intrarater intersession reproducibility of the Nintendo Wii agility and stillness tests and explore the concurrent validity in relation to gold-standard force-plate analysis. Within-day intersession reproducibility was examined in 30 older adults (age 71.8 ± 5.1 yr). No systematic test-retest differences were found for the Wii stillness test; however, the Wii agility test scores differed systematically between test sessions (p < .05). The Wii stillness test yielded a test-retest ICC of .86 (95% CI 0.74-0.93), CV of 6.4%, LOA of 11.0, and LOA% of 17.9%. Likewise for the Wii agility test ICC was .73 (95% CI 0.50-0.86), CV 5.3%, LOA 1.8, and LOA% of 14.6%. Wii stillness scores correlated to force plate measures (r = .65-.82, p < .01), reflecting moderate to excellent validity. In conclusion, it appears that the Wii stillness test represents a low-cost, objective, reproducible, and valid test of undisturbed postural balance in community-dwelling older adults.