Prevalence and correlates of sleep disorders in Parkinson’s disease: a polysomnographic study

Objective Sleep disorders in Parkinson’s disease are very common. Polysomnography (PSG) is considered the gold standard for diagnosis. The aim of the present study is to assess the prevalence of nocturnal sleep disorders diagnosed by polysomnography and to determine the associated clinical factors. Method A total of 120 patients with Parkinson’s disease were included. All patients underwent a standardized overnight, single night polysomnography. Results Ninety-four (78.3%) patients had an abnormal PSG. Half of the patients fulfilled criteria for sleep apnea-hypopnea syndrome (SAHS); rapid eye movement behavior disorder (RBD) was present in 37.5%. Characteristics associated with SAHS were age (p = 0.049) and body mass index (p = 0.016). Regarding RBD, age (p < 0.001), left motor onset (p = 0.047) and levodopa equivalent dose (p = 0.002) were the main predictors. Conclusion SAHS and RBD were the most frequent sleep disorders. Higher levodopa equivalent dose and body mass index appear to be risk factors for RBD and SAHS, respectively

Low specificity and sensitivity of smell identification testing for the diagnosis of Parkinson?s disease

Objective: The aim of this study is to determine if the University of Pennsylvania’s Smell Identification Test (UPSIT) is an accurate diagnostic tool for olfactory dysfunction in Parkinson’s disease (PD). Method: We included 138 non-demented PD subjects and 175 control subjects matched by gender. Smell identification was tested using UPSIT. Results: The mean number of UPSIT items correctly identified by controls was 27.52±5.88; the mean score for PD subjects was 19.66±6.08 (p=<0.001). UPSIT sensitivity was 79.7% with a specificity of 68.5% using a cut-off score of ≤25. The overall accuracy for the diagnosis of PD was of 75.3%. Conclusion: UPSIT accuracy and specificity were lower than what has been previously reported. Our data demonstrates that 17.5% of items of the UPSIT were not well identified by healthy controls. Further research of the identification of a truly cross-cultural test is warranted