Olfactory function in Parkinson's Disease - effects of training

• Published in: Acta neurologica Scandinavica Vol. 132; no. 6; pp. 395 - 400
• Main Authors: Knudsen, K., Flensborg Damholdt, M., Mouridsen, K., Borghammer, P.
• Format: Journal Article
• Language: English
• Published: Denmark Blackwell Publishing Ltd 01-12-2015; Hindawi Limited
• Subjects: Aged; Cognition; Discrimination (Psychology); Dopamine Plasma Membrane Transport Proteins - metabolism; Female; Humans; hyposmia; Incidence; Learning; Male; Middle Aged; Neuropsychological Tests; olfaction; Olfaction Disorders - epidemiology; Olfaction Disorders - psychology; Panic attacks; Parkinson Disease - diagnostic imaging; Parkinson Disease - psychology; Parkinson Disease - rehabilitation; Parkinson's disease; Patients; Psychomotor Performance; Putamen - diagnostic imaging; Quality of Life; Sensation; single photon emission computed tomography (SPECT); Smell; Studies; Surveys and Questionnaires; Tomography, Emission-Computed, Single-Photon; training effect; olfaction; training effect; Parkinson's disease; single photon emission computed tomography (SPECT); hyposmia
• ISSN: 0001-6314; 1600-0404
• DOI: 10.1111/ane.12406

Background
Up to 90% of patients with Parkinson's disease (PD) exhibit olfactory dysfunction, but little is known about the effects of olfactory training. The study aim was to investigate whether the ability to identify olfactory stimuli can be improved by means of a brief training session. Furthermore, the impact of hyposmia on quality of life in PD was investigated by means of a questionnaire.
Methods
Olfactory function was rated in 34 patients with PD and in 26 controls before and after a training session. An additional 20 patients with PD served as a control group and were tested twice without an intervening training session. Long‐term effects were evaluated in a small subset of patients. Cognitive tests and DaT SPECT scans were performed.
Results
We demonstrated significant same‐day and long‐term training effects in trained PD patients compared with non‐trained PD patients. A slightly significant correlation was seen between the training effect and DaT putamen values, but not with cognitive test scores. Furthermore, patients with PD reported that hyposmia significantly decreased their quality of life.
Conclusions
Patients with PD improved the number of correctly identified odors in an olfactory test through a brief training session. Olfactory training may have potential in rehabilitation of patients with PD.