Consistency and Stability of Motor Subtype Classifications in Patients With de novo Parkinson’s Disease

Abstract

ObjectivePatients with Parkinson’s disease (PD) are commonly classified into subtypes based on motor symptoms. The aims of the present study were to determine the consistency between PD motor subtypes, to assess the stability of PD motor subtypes over time, and to explore the variables influencing PD motor subtype stability.MethodsThis study was part of a longitudinal study of de novo PD patients at a single center. Based on three different motor subtype classification systems proposed by Jankovic, Schiess, and Kang, patients were respectively categorized as tremor-dominant/indeterminate/postural instability and gait difficulty (TD/indeterminate/PIGD), TDS/mixedS/akinetic-rigidS (ARS), or TDK/mixedK/ARK at baseline evaluation and then re-assessed 1 month later. Demographic and clinical characteristics were recorded at each evaluation. The consistency between subtypes at baseline evaluation was assessed using Cohen’s kappa coefficient (κ). Additional variables were compared between PD subtype groups using the two-sample t-test, Mann–Whitney U-test or Chi-squared test.ResultsOf 283 newly diagnosed, untreated PD patients, 79 were followed up at 1 month. There was fair agreement between the Jankovic, Schiess, and Kang classification systems (κS = 0.383 ± 0.044, κK = 0.360 ± 0.042, κSK = 0.368 ± 0.038). Among the three classification systems, the Schiess classification was the most stable and the Jankovic classification was the most unstable. The non-motor symptoms questionnaire (NMSQuest) scores differed significantly between PD patients with stable and unstable subtypes based on the Jankovic classification (p = 0.008), and patients with a consistent subtype had more severe NMSQuest scores than patients with an inconsistent subtype.ConclusionFair consistency was observed between the Jankovic, Schiess, and Kang classification systems. For the first time, non-motor symptoms (NMSs) scores were found to influence the stability of the TD/indeterminate/PIGD classification. Our findings support combining NMSs with motor symptoms to increase the effectiveness of PD subtypes.

Nigral neuropathology of Parkinson’s motor subtypes coincide with circuitopathies: a scoping review

“…While authors found that 79% of those in the mild motor-predominant subtype were TD and 33% of the diffuse malignant subtype were PIGD, the tremor/PIGD classifications alone could not predict prognosis unlike their global subtyping solution that integrated additional daily living and cognition factors (Fereshtehnejad et al 2017 ). These results speak towards the utility of incorporating various motor and non-motor symptoms as well as other biomarkers in the identification of PD subtypes, as more multivariate groupings may produce greater clinical applications and prove more stable over time (Ren et al 2021 ). It is still unknown why certain subpopulations of cells undergo different degeneration patterns within each PD subtype, what initiates these divergences, whether they are a cause or a consequence of other co-occurring pathogenic mechanisms, and how they may be best targeted for treatment.…”

Stability of MDS-UPDRS Motor Subtypes Over Three Years in Early Parkinson's Disease

“…To date, only one previous study has investigated motor subtypes using the criteria set by Stebbins et al However, one limitation of that study was that the study had a short followup duration of 12 months (19). Another recent study studied the various subtyping methods and their stability, but had a relatively short follow-up period of 1 month (20). We, therefore, undertook this study to understand (1) the distribution of pre-defined motor subtypes of PD using the MDS-UPDRS criteria, (2) their stability over 3 years, and (3) determine independent factors predicting the stability of these subtypes.…”

A feasibility study of dual-task strategy training to improve gait performance in patients with Parkinson’s disease

“…In a subset of PD patients (n = 9), further assessments were available (mean MDS-UPDRS III 24 ± 8.2 with medication, mean disease duration of 8.5 ± 5.0 years, LEDD 1048.4 mg ± 683.4 mg). Most of the PD patients were of the akinetic-rigid subtype (67%), two PD patients had implanted STN-DBS 33 . All patients were tested in everyday conditions with medication and DBS switched on.…”