Relationship between the type and side of motor symptoms with the prevalence of non-motor symptoms in Parkinson's disease

Introduction: the relationship between laterality and asymmetry of Parkinson's disease and non-motor dysfunction has been studied mainly from the perspective of cognitive functions, and the few studies that have included other symptoms have mixed reports. The relationship between non-motor symptoms and the type of onset of the disease has not been studied in detail.

Objective: to analyse the association between the side and type of motor onset and the prevalence of non-motor symptoms.

Patients and methods: we included 232 patients diagnosed with Parkinson's disease. Type of onset and the side initially affected were documented. The presence of non-motor symptoms was determined by applying the non-motor symptom questionnaire (NMSQuest).

Results: when analysing the side of onset and presence of each non-motor symptom explored, statistically significant differences were found in the frequency of hallucinations (P=0.04) and sleep behaviour disorder (P<0.01) in subjects with right side onset. The motor type of onset differences were not statistically significant.

Conclusions: subjects with right side onset seem to have a higher risk of having hallucinations and sleep behaviour disorders. These symptoms should be intentionally sought in order to provide treatment and improve the patient's quality of life.