Parkinson's disease subtypes: lost in translation?

Marras, Connie; Lang, Anthony E.

doi:10.1136/jnnp-2012-303455

Cited by 200 publications

(143 citation statements)

References 34 publications

(45 reference statements)

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“…Clinical separation into PIGD and TD types has been the most extensively studied classification method [33,34]. Just recently, a new formula was introduced whilst optimal sensitivity and specificity were obtained with MDS-UPDRS cutoff-scores of C1.15 for TD classification and B0.90 for PIGD [35].…”

Section: Considerations In Regards To Classification Into Pigd and Tdmentioning

confidence: 99%

Gait and balance in Parkinson’s disease subtypes: objective measures and classification considerations

et al. 2014

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Parkinson's disease (PD) is often divided into tremor dominant (TD) and postural instability gait difficulty (PIGD) subtypes. However, objective measures of gait (e.g., stride length, variability) and balance have not been well studied in these subtypes. To better understand these motor subtypes, we objectively quantified gait and balance and their behavioral correlates. 110 patients with PD underwent a clinical evaluation and were stratified into PIGD and TD subtypes. Participants walked under single and dual task conditions while wearing a single body-fixed sensor, both "OFF" and "ON" medications and at home for 3 days. We also examined performance-based tests of mobility, balance, and fall risk. Stricter criteria were also applied, dividing the subjects into predominant representative subgroups: p-PIGD and p-TD. Both the PIGD (n = 62) and TD (n = 42) groups and the p-PIGD (n = 31) and p-TD (n = 32) subgroups were similar with respect to basic disease characteristics (e.g., disease duration, p > 0.69). Surprisingly gait speed, stride length, and variability did not differ between the PIGD and TD groups (p > 0.05). In contrast, the p-PIGD group had reduced gait speed (under single and dual task conditions), shorter strides, increased stride variability, and decreased stride regularity (regularity: p-PIGD 0.66 ± 0.10; p-TD 0.74 ± 0.08; p = 0.003). The p-PIGD group also scored worse on performance-based tests, compared to the p-TD. Clinical assessments of the disturbances seen in patients with the PIGD subtype are not consistent with objective measures; overlapping between the groups is seen in many objective features of gait and balance. These findings suggest that the proposed alternate classification scheme may be useful.

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Section: Considerations In Regards To Classification Into Pigd and Tdmentioning

confidence: 99%

Gait and balance in Parkinson’s disease subtypes: objective measures and classification considerations

et al. 2014

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“…22,23 So far, none of the proposed subtype classifications appears sufficiently robust to warrant formal delineation. 22 Our findings suggest that in future classifications, early-onset and late-onset subtypes should also be considered.…”

Section: Allmentioning

confidence: 99%

Age at onset and Parkinson disease phenotype

et al. 2016

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Objective: To explore clinical phenotype and characteristics of Parkinson disease (PD) at different ages at onset in recently diagnosed patients with untreated PD. Methods:We have analyzed baseline data from the Parkinson's Progression Markers Initiative database. Four hundred twenty-two patients with a diagnosis of PD confirmed by DaTSCAN imaging were divided into 4 groups according to age at onset (onset younger than 50 years, 50-59 years, 60-69 years, and 70 years or older) and investigated for differences in side, type and localization of symptoms, occurrence/severity of motor and nonmotor features, nigrostriatal function, and CSF biomarkers.Results: Older age at onset was associated with a more severe motor and nonmotor phenotype, a greater dopaminergic dysfunction on DaTSCAN, and reduction of CSF a-synuclein and total tau. The most common presentation was the combination of 2 or 3 motor symptoms (bradykinesia, resting tremor, and rigidity) with rigidity being more common in the young-onset group. In about 80% of the patients with localized onset, the arm was the most affected part of the body, with no difference across subgroups. Conclusions:Although the presentation of PD symptoms is similar across age subgroups, the severity of motor and nonmotor features, the impairment of striatal binding, and the levels of CSF biomarkers increase with age at onset. The variability of imaging and nonimaging biomarkers in patients with PD at different ages could hamper the results of future clinical trials.

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“…There are 3 commonly identified subtypes of PD, based on the main motor symptoms: tremor dominant, postural instability gait disorder and akinetic-rigid [1,2]. Cognitive decline is frequently observed in people diagnosed with PD (PwPD) even at the onset of the disease, with over 80% having some cognitive impairment or dementia within 15 years of onset [3].…”

mentioning

confidence: 99%

Pattern of Executive Impairment in Mild to Moderate Parkinson's Disease

Kudlicka¹,

Clare²,

Hindle

2013

Dement Geriatr Cogn Disord

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Background/Aims: The exact pattern of impairment in executive functions (EF) among people with Parkinson's disease (PD) is still debated. Using a data-driven approach we investigated which areas of EF are particularly problematic in mild to moderate PD. Methods: Thirty-four patients with mild to moderate PD, who scored in the normal range on general cognition screening tests, but displayed frontal-type deficits indicated by Frontal Assessment Battery screening, completed the 9 tests that comprise the Delis-Kaplan Executive Function System. Patterns of performance were explored using cluster analysis and principal component analysis (PCA), and the frequency of impairments was established using normative data. Results: Both cluster analysis and PCA identified two distinct groups of EF tests. The first group included tests requiring time-efficient attentional control (e.g. the Trail Making test). The second group included tests measuring abstract reasoning and concept formation abilities (e.g. the 20 Questions test). Impairment was more frequent on the attentional control tests than on the abstract thinking tests. Conclusion: PD pathology in the mild to moderate PD appears to affect the attentional control aspect of EF to a greater extent than abstract reasoning. Understanding the nature of executive deficits in PD is important for the development of targeted pharmacological and cognitive interventions for cognitive disturbances.

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Parkinson's disease subtypes: lost in translation?

Cited by 200 publications

References 34 publications

Gait and balance in Parkinson’s disease subtypes: objective measures and classification considerations

Gait and balance in Parkinson’s disease subtypes: objective measures and classification considerations

Age at onset and Parkinson disease phenotype

Pattern of Executive Impairment in Mild to Moderate Parkinson's Disease

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