High prevalence of olfactory dysfunction in cervical dystonia. (August 2018)

• Record Type: Journal Article
• Authors: Marek, Milena; Linnepe, Susanne; Klein, Christine; Hummel, Thomas; Paus, Sebastian
• Is Part Of: Parkinsonism & related disorders. Volume 53(2018)
• Page Start: 33
• Page End: 36
• Publication Date: 2018-08
• Subjects: Cervical dystonia -- Olfactory dysfunction; Parkinson's disease -- Periodicals; Movement disorders -- Periodicals; Movement Disorders -- Periodicals; Nerve Degeneration -- Periodicals; Nervous System Diseases -- Periodicals; Parkinson Disease -- Periodicals; Tremor -- Periodicals; Parkinson, Maladie de -- Périodiques; Parkinson's disease; 616.833
• DOI: 10.1016/j.parkreldis.2018.04.028
• Languages: English
• ISSNs: 1353-8020

Abstract

Abstract: Introduction: Olfactory dysfunction has been established as a frequent non-motor symptom in neurodegenerative and movement disorders such as Parkinson's disease, Alzheimer's disease, and hereditary ataxias. To expand knowledge of non-motor symptoms in dystonia, and to test for a potential endophenotype, we examined olfactory function in cervical dystonia (CD). Methods: In patients with CD, and neurologically healthy controls, olfactory function was examined by " Sniffin' Sticks ", a test of nasal chemosensory function based on pen-like odor dispensing devices. This test enables to define an individual's odor threshold, odor discrimination, and odor identification. Owing to the etiological heterogeneity of olfactory dysfunction, strict exclusion criteria were applied, especially smoking, and sinonasal disease. Results: 58 CD patients completed the study. Olfactory dysfunction was present in 29 patients (50.0%), significantly more frequent than in two groups of matched healthy control subjects (20.7%; 22.4%; p = 0.001). Analysis of the pattern of hyposmia revealed that odor threshold ( p = 0.002), and odor identification ( p < 0.001) were significantly worse in CD patients compared to controls, while odor discrimination was unchanged. Higher age was the only clinical characteristic to correlate with olfactory dysfunction in CD. Conclusions: Our observations establish olfactory dysfunction, possibly of both peripheral and central origin, as a new non-motor, and probably motor-unrelated, symptom of CD. Additionally, the potential involvement of cerebellar functions in olfactory identification and discrimination tasks, as well as in pathophysiology of dystonia, justifies further studies of olfactory dysfunction as a possible endophenotype in dystonia. Highlights: Olfactory dysfunction was seen in about 52% of patients with cervical dystonia. Olfactory dysfunction is a common non-motor and probably motor-unrelated symptom in cervical dystonia. Results of olfactory testing refer to possibly both peripheral and central origin of hyposmia.