Remor, bradykinesia and axial scores) Intermediate Progression rate Intermediate depression, anxiety and frontal cognitive impairment High NMS score (Urinary domain selectively affected)Group 4 – MD (n = 20) 62 years at onset High UPDRS III score (with high bradykinesia and axial scores) High Progression rate High depression, anxiety and frontal cognitive impairment Intermediate NMS scoreIntermediate UPDRS III score (with mild Low UPDRS III score (with low tremor tremor and bradykinesia scores) and bradykinesia scores) Intermediate Progression rate Low Progression rate Absent depression, anxiety and frontal cognitive impairment Very low NMS score (Memory, Sleep and Psychiatric CAL-120 chemical information domains selectively spared) doi:10.1371/journal.pone.Fexinidazole price 0070244.t004 Mild depression, anxiety and frontal cognitive impairment Intermediate NMS score (Sex domain selectively affected)The Heterogeneity of Early Parkinson’s DiseaseFigure 1. Summary of main features of the clusters according to clinical involvement, severity and age at onset. doi:10.1371/journal.pone.0070244.gscores measuring total NMS and NMS-D reflect more the involvement of different non-motor domains, rather than an index of their severity. It means that the NMD cluster would have widespread involvement of NMS-D, but milder non-motor severity (at least regarding depression, anxiety and frontal impairment) compared to MD group, possibly suggesting a mild to moderate dopaminergic degeneration (as also confirmed by the intermediate motor scores) and the involvement of extra-dopaminergic systems, which instead would be relatively spared in the MD group. The latter would therefore show an attitude for the involvement of such non-motor features (i.e. frontal-type cognitive deficits and neuropsychiatric issues), which have been consistently linked to the striatal dopaminergic denervation [12,40?4], whereas the NMD cluster would have a widespread involvement of several NMS-D, with possibly further underpinning mechanisms. One would suspect some NMS-D such as urinary, gastrointestinal and cardiovascular (i.e. all domains which have been to supposed to be part of the autonomic system) to travel together. We failed to identify clear patterns of non-motor grouping in such sense. A limitation which may accounts for this is that the NMSQuest simply detects the involvement of different domains, including such as the gastrointestinal, which may be not specific for PD. Moreover, by considering disaggregated items according to their own relevance (i.e., not the raw number of gastrointestinal symptoms but a measure of the intensity of each one of them), it may be possible to disclose more delineated non-motor grouping. The relative low frequency of some NMS (due to the nature of our cohort of de-novo patients) may have further accounted for such lack of non-motor grouping. Nevertheless, we found clear nonmotor differences between groups. For instance, NMD is characterized by urinary issues while MD is characterized by cognitive/neuropsychiatric symptoms, suggesting that these twoNMS-D travel separately, in line with other reports [45]. It may further indicate that such two groups (i.e., the “advanced” clusters, which to some extent share a common pattern of motor disability) may be prone to develop either autonomic or neuropsychiatric issues, respectively, but this needs to be clarified in further longitudinal studies. Finally, the logistic regression showed that total UPDRS III, Sexual disturbances and Acting out d.Remor, bradykinesia and axial scores) Intermediate Progression rate Intermediate depression, anxiety and frontal cognitive impairment High NMS score (Urinary domain selectively affected)Group 4 – MD (n = 20) 62 years at onset High UPDRS III score (with high bradykinesia and axial scores) High Progression rate High depression, anxiety and frontal cognitive impairment Intermediate NMS scoreIntermediate UPDRS III score (with mild Low UPDRS III score (with low tremor tremor and bradykinesia scores) and bradykinesia scores) Intermediate Progression rate Low Progression rate Absent depression, anxiety and frontal cognitive impairment Very low NMS score (Memory, Sleep and Psychiatric domains selectively spared) doi:10.1371/journal.pone.0070244.t004 Mild depression, anxiety and frontal cognitive impairment Intermediate NMS score (Sex domain selectively affected)The Heterogeneity of Early Parkinson’s DiseaseFigure 1. Summary of main features of the clusters according to clinical involvement, severity and age at onset. doi:10.1371/journal.pone.0070244.gscores measuring total NMS and NMS-D reflect more the involvement of different non-motor domains, rather than an index of their severity. It means that the NMD cluster would have widespread involvement of NMS-D, but milder non-motor severity (at least regarding depression, anxiety and frontal impairment) compared to MD group, possibly suggesting a mild to moderate dopaminergic degeneration (as also confirmed by the intermediate motor scores) and the involvement of extra-dopaminergic systems, which instead would be relatively spared in the MD group. The latter would therefore show an attitude for the involvement of such non-motor features (i.e. frontal-type cognitive deficits and neuropsychiatric issues), which have been consistently linked to the striatal dopaminergic denervation [12,40?4], whereas the NMD cluster would have a widespread involvement of several NMS-D, with possibly further underpinning mechanisms. One would suspect some NMS-D such as urinary, gastrointestinal and cardiovascular (i.e. all domains which have been to supposed to be part of the autonomic system) to travel together. We failed to identify clear patterns of non-motor grouping in such sense. A limitation which may accounts for this is that the NMSQuest simply detects the involvement of different domains, including such as the gastrointestinal, which may be not specific for PD. Moreover, by considering disaggregated items according to their own relevance (i.e., not the raw number of gastrointestinal symptoms but a measure of the intensity of each one of them), it may be possible to disclose more delineated non-motor grouping. The relative low frequency of some NMS (due to the nature of our cohort of de-novo patients) may have further accounted for such lack of non-motor grouping. Nevertheless, we found clear nonmotor differences between groups. For instance, NMD is characterized by urinary issues while MD is characterized by cognitive/neuropsychiatric symptoms, suggesting that these twoNMS-D travel separately, in line with other reports [45]. It may further indicate that such two groups (i.e., the “advanced” clusters, which to some extent share a common pattern of motor disability) may be prone to develop either autonomic or neuropsychiatric issues, respectively, but this needs to be clarified in further longitudinal studies. Finally, the logistic regression showed that total UPDRS III, Sexual disturbances and Acting out d.
