The interrelationship between non-motor symptoms in Atypical Parkinsonism.

Background: Atypical Parkinsonism is less common and has more severe symptoms than Parkinson's disease (PD). Little is known about the non-motor symptom (NMS) characteristics of multiple systemic atrophy (MSA) or progressive supranuclear palsy (PSP). We report the interrelationship of NMS in MSA, PSP, and PD.

Methods: We studied 117 cases of PD and 57 of Atypical Parkinsonism. Out of the 57 patients, 31 had multiple systemic atrophy parkinsonian subtype (MSA-P), 14 had multiple systemic atrophy cerebellar dysfunction subtype (MSA-C), and 12 had PSP. We assessed the condition of the patients using the United Parkinson's Disease Rating Scale part III (UPDRS-III), the modified Hoehn & Yahr scale (H&Y), the non-motor symptom scale (NMSS), and the Parkinson's Disease Questionnaire (PDQ-39).

Results: In Atypical Parkinsonism, the NMSS scores significantly correlated with PDQ-39 scores, but not with UPDRS-III. In the MSA-P group, the mood/cognitive domain significantly correlated with both the urinary and sleep/fatigue domains. In the MSA-C group, the sleep/fatigue domain correlated with the mood/cognition and cardiovascular domains. Finally, in the PSP and PD groups, the attention/memory domain significantly correlated with the sleep/fatigue and mood/cognition domains.

Discussion: These results suggest that, with respect to cognitive function, dysautonomia and sleep/fatigue are detrimental factors in MSA and PSP, respectively.