Contributions of mild parkinsonian signs to gait performance in the elderly

Abstract

Mild parkinsonian signs (MPS) and gait abnormalities are common in aging, but the association between MPS and objective gait measures is not established in the elderly. This study aims to identify the link between MPS and quantitative gait measures, as well as to determine the pathogenesis of MPS in nondemented community-dwelling older adults without idiopathic Parkinson's disease or other parkinsonian syndromes. Three hundred seventy-four non-demented older adults (mean age, 76.44±6.71 years, 57 % women) participated in this study, where comprehensive neurological and medical assessments were conducted. We defined MPS based on the presence of any one of bradykinesia, rigidity, or rest tremor. Velocity and spatial, temporal, and variability gait parameters were recorded using an instrumented walkway. The associations of MPS and gait parameters as well as the relationship of individual MPS with medical illnesses were assessed with linear regressions controlling for key covariates. Participants with MPS walked slower and with disturbed spatial and variability components of gait compared to those without MPS. Bradykinesia was associated with worse spatial and variability gait parameters. This association was only significant for axial bradykinesia, but not for the presence of bradykinesia in the limbs. Cerebrovascular disease (β=.20, p<.01) was associated with bradykinesia, whereas cardiovascular disease (β=.15, p<.05) was associated with rigidity. Among MPS, bradykinesia but not rigidity or tremor was associated with worse quantitative gait performance in older adults. Cerebrovascular disease, a preventable condition, was specifically associated with bradykinesia.

The role of postural instability/gait difficulty and fear of falling in predicting falls in non-demented older adults

“…Individual EPS were calculated by summing clinician ratings (0–4) within 4 core domains: 1) PIGD (UPDRS#29-30); 2) bradykinesia (UPDRS#23-26, 31); 3) rigidity (UPDRS#22); and 4) rest tremor (UPDRS#20). In accordance with our previous studies, EPS were diagnosed by the presence of any one of these four cardinal domains; this approach has shown good internal reliability (Allali et al, 2014; Mahoney et al, 2014). Mild PIGD and other EPS features were defined by the presence of one point in any one of the EPS features; and moderate/severe PIGD and other EPS features were defined by a severity score > 1.…”

“…Measuring FoF with two validated instruments (Oh-Park et al, 2011; Powell and Myers, 1995) in combination with a validated comprehensive neurological assessment of EPS (Allali et al, 2014; Mahoney et al, 2014) represents the main strengths of this longitudinal study. However, some limitations should be acknowledged: as no validated scale for identifying extrapyramidal symptoms exists in older adults without PD, we used the UPDRS validated in PD patients to assess EPS, like in previous studies conducted by different research groups (Allali et al, 2014; Buchman et al, 2012; de Laat et al, 2012); although we excluded participants with dementia, recall bias could still affect the report of incidental fall by using a bi-monthly telephone interview or by reporting fear of falling at baseline assessment; this very healthy sample (GHS: 1.63 ± 1.06) with the consequence of a low impact of EPS (EPS total score: 2.51 ± 3.77) forces us to use EPS feature as a 3 steps scale (no; mild; moderate/severe) instead of a continuous measure; similarly, the low prevalence of rest tremor (6%) prevents us to study this EPS feature, as a falls predictor; a measure of the various drug classes was not included as covariate in our analyses; and finally, the highly functioning study sample could limit the generalization of the study findings.…”

The role of prefrontal cortex during postural control in Parkinsonian syndromes a functional near-infrared spectroscopy study

“…All participants were categorized into one of three groups: MPS, PS, or healthy control (i.e., normal). As in our previous studies (Allali et al, 2014a; Mahoney et al, 2014), MPS were systematically ascertained in participants by the study clinician using the motor evaluation portion (Part III) of the original version of the Unified Parkinson’s Disease Rating Scale (UPDRS; Fahn and Elton, 1987). MPS diagnosis was based on the presence of any one of the four cardinal features (bradykinesia, rigidity, rest tremor, or postural instability and gait disturbance, regardless of its severity (see Section 4 for specific details).…”

The evolution of mild parkinsonian signs in aging

“…Gait velocity in the elderly represents a final pathway combining balance, motor, sensory systems, as well as cognition [30]. In addition, the fact that gait velocity predicted persistent MPS is supported by recent findings in non-demented older adults without idiopathic PD: bradykinesia that represents a required feature for parkinsonism has been associated with gait velocity [21]. From a metabolic perspective, gait speed was associated with cholinergic but not dopaminergic denervation in PD patients; [31] suggesting a close relationship between gait and the cholinergic system.…”

“…A total MPS score was subsequently created, both at baseline and at follow-up, by adding the severity indices of the individual MPS. As in our previous work, we aimed to identify early markers of abnormal motor aging by taking a sensitive approach to define MPS based on the presence of any one feature of MPS [21], but more stringent methods have previously been employed [7, 10]. For the MPS severity score, the Cronbach’s α of 0.85 indicated good internal consistency, with excellent internal consistency for bradykinesia (0.90) and tremor (0.90), and good internal consistency for rigidity (0.88).…”