Lavender Discrimination in Parkinson’s Disease

The scent of lavender has been purported to promote sleep in patients with neurodegenerative disease, but an obvious paradox is how, given the widely recognized deficits in olfaction observed in such patients, such an effect could occur. In this study we examined the ability of Parkinson’s Disease patients to discriminate lavender from rose in a forced-choice discrimination task. Results indicated that most Parkinson’s patients could not discriminate lavender above chance, although about a third were able to do so. This preserved ability was unrelated to disease severity or years with diagnosis. It was unrelated to age- and sex-adjusted performance on a standardized test of olfaction (University of Pennsylvania Smell Identification Test). These results were compatible with lavender’s potential impact via trigeminal afferents and leave open the possibility that lavender could indeed impact sleep in some patients with neurodegenerative disease.