Traumatic brain injury and olfactory deficits: the tale of two smell tests!

PRIMARY OBJECTIVE

Olfactory functions are not systematically evaluated following traumatic brain injury (TBI). This study aimed at comparing two smell tests that are used in a clinical setting.

RESEARCH DESIGN

The University of Pennsylvania Smell Identification Test (UPSIT) and the Alberta Smell Test were compared in terms of assessment time, cost and diagnosis. Parameters associated with olfactory loss such as injury severity, type of cerebral lesion and depressive data were considered. Forty-nine TBI patients admitted to an outpatient rehabilitation programme took part in this experiment.

RESULTS

The scores of the two smell tests were significantly correlated. Both tests indicated that patients with frontal lesion performed significantly worse than patients with other types of lesion. Mood and injury severity were not associated with olfactory impairment when age was taken into account. Between 40-44% of the patients showing olfactory impairments were not aware of their deficit.

CONCLUSIONS

Since a significant proportion of the patients showing olfactory impairments were not aware of their deficit, it is recommended than clinicians systematically evaluate olfactory functions using the Alberta Smell test. To refine their diagnosis, the UPSIT can also be used.