Neuropsychology, Vol 30(1), Jan 2016, 87-97. http://dx.doi.org.ezp1.lib.umn.edu/10.1037/neu0000212
- Objective: To examine changes in odor identification performance and cognitive measures in healthy aging individuals. While cross-sectional studies reveal associations between odor identification and measures of episodic memory, processing speed, and executive function, longitudinal studies so far have been ambiguous with regard to demonstrating that odor identification may be predictive of decline in cognitive function. Method: One hundred and 7 healthy aging individuals (average age 60.2 years, 71% women) were assessed with an odor identification test and nonolfactory cognitive measures of verbal episodic memory, mental processing speed, executive function, and language 3 times, covering a period of 6.5 years. Results: The cross-sectional results revealed odor identification performance to be associated with age, measures of verbal episodic memory, and processing speed. Using linear mixed models, the longitudinal analyses revealed age-associated decline in all measures. Controlling for retest effects, the analyses demonstrated that gender was a significant predictor for episodic memory and mental processing speed. Odor identification performance was further shown to be a significant predictor for episodic verbal memory. Conclusion: This study shows age-related decline in odor identification as well as nonolfactory cognitive measures. The finding showing that odor identification is a significant predictor for verbal episodic memory is of great clinical interest as odor identification has been suggested as a sensitive measure of incipient pathologic cognitive decline. (PsycINFO Database Record (c) 2015 APA, all rights reserved)
Olfactory identification and its relationship to executive functions, memory, and disability one year after severe traumatic brain injury.
Sigurdardottir, Solrun; Andelic, Nada; Skandsen, Toril; Anke, Audny; Roe, Cecilie; Holthe, Oyvor Oistensen; Wehling, Eike
Neuropsychology, Vol 30(1), Jan 2016, 98-108. http://dx.doi.org.ezp1.lib.umn.edu/10.1037/neu0000206
- Objective: To explore the frequency of posttraumatic olfactory (dys)function 1 year after severe traumatic brain injury (TBI) and determine whether there is a relationship between olfactory identification and neuropsychological test performance, injury severity and TBI-related disability. Method: A population-based multicenter study including 129 individuals with severe TBI (99 males; 16 to 85 years of age) that could accomplish neuropsychological examinations. Olfactory (dys)function (anosmia, hyposmia, normosmia) was assessed by the University of Pennsylvania Smell Identification Test (UPSIT) or the Brief Smell Identification Test (B-SIT). Three tests of the Delis-Kaplan Executive Function System (D-KEFS) were used to assess processing speed, verbal fluency, inhibition and set-shifting, and the California Verbal Learning Test-II was used to examine verbal memory. The Glasgow Outcome Scale-Extended (GOSE) was used to measure disability level. Results: Employing 2 different smell tests in 2 equal-sized subsamples, the UPSIT sample (n = 65) classified 34% with anosmia and 52% with hyposmia, while the B-SIT sample (n = 64) classified 20% with anosmia and 9% with hyposmia. Individuals classified with anosmia by the B-SIT showed significantly lower scores for set-shifting, category switching fluency and delayed verbal memory compared to hyposmia and normosmia groups. Only the B-SIT scores were significantly correlated with neuropsychological performance and GOSE scores. Brain injury severity (Rotterdam CT score) and subarachnoid hemorrhage were related to anosmia. Individuals classified with anosmia demonstrated similar disability as those with hyposmia/normosmia. Conclusions: Different measures of olfaction may yield different estimates of anosmia. Nevertheless, around 1 third of individuals with severe TBI suffered from anosmia, which may also indicate poorer cognitive outcome. (PsycINFO Database Record (c) 2015 APA, all rights reserved)