Objective: To investigate the prevalence of loss sense of smell and its possible link with the natural history of PD.

Background: Non-motor symptoms (NMS) in Parkinson’s disease (PD) are important to investigate because they substantially affect patients and carers quality of life.

Methods: This is an open cross-sectional observational study, involving 112 patients (72 males and 40 females; age range 49-89 years (mean =71 (SD+7.82)), selected from a local PD database with a confirmed clinical diagnosis of PD.

The 40 item University of Pennsylvania Smell Identification Test (UPSIT) was used to test sense of smell. Motor symptoms were measured using the Unified Parkinson’s Disease Rating Scale (UPDRS-III), NMS were assessed using the NMS Questionnaire, quality of life was measured using PDQ39 Quality of Life Questionnaire, disease stage was measured using Hoehn and Yahr scale, rapid eye movement behaviour disorder was assessed using the RBD Screening Questionnaire and cognitive state was assessed using Montreal Cognitive Assessment. 

Results: UPSIT scores showed that no PD patient had a normal sense of smell. (75 patients had anosmia, 27 patients had severe microsmia, and 10 patients had mild/moderate microsmia).  Females had an overall higher median UPSIT score than males (p=0.024). There was a trend in reduction in sense of smell as PD patients get older (r=-0.210; (p=0.026). 

Only 33% of the study group self-reported decreased sense of smell which was started I month to 60 years (before PD diagnosis),  with a mean loss of sense of smell (pre-diagnosis period) of 7 years.

Furthermore, 29 out of the 33 PD patients (self-reporting normal sense of smell) had, in fact, a severe degree of sense of smell loss (UPSIT range 7-25;  mean=16 )

Furthermore, ten (9%) patients reported phantosmia whose UPSIT scores lower but not statistically significant compared to those patients reporting no phantosmia (P=0.095) 

Conclusions: The findings of this study conclude that 100% of this study sample had an abnormal sense of smell and that self-reporting of smell dysfunction is regarded as too unreliable and needs formal testing.  This may then support the need to review the Parkinson’s Disease National Institute for Health and Clinical Excellence Guideline (2006) on treatment and management for Parkinson’s disease.

« Back to 2017 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/are-patients-with-parkinsons-disease-who-have-either-mild-to-moderate-microsmia-severe-microsmia-or-anosmia-clinically-different/