Quincy J. Almeida

Bio: Quincy J. Almeida is an academic researcher from Wilfrid Laurier University. The author has contributed to research in topics: Gait (human) & Parkinson's disease. The author has an hindex of 30, co-authored 111 publications receiving 2912 citations. Previous affiliations of Quincy J. Almeida include McMaster University & London Health Sciences Centre.

Gait impairments in Parkinson's disease.

Abstract: Summary Gait impairments are among the most common and disabling symptoms of Parkinson's disease. Nonetheless, gait is not routinely assessed quantitatively but is described in general terms that are not sensitive to changes ensuing with disease progression. Quantifying multiple gait features (eg, speed, variability, and asymmetry) under natural and more challenging conditions (eg, dual-tasking, turning, and daily living) enhanced sensitivity of gait quantification. Studies of neural connectivity and structural network topology have provided information on the mechanisms of gait impairment. Advances in the understanding of the multifactorial origins of gait changes in patients with Parkinson's disease promoted the development of new intervention strategies, such as neurostimulation and virtual reality, aimed at alleviating gait impairments and enhancing functional mobility. For clinical applicability, it is important to establish clear links between specific gait impairments, their underlying mechanisms, and disease progression to foster the acceptance and usability of quantitative gait measures as outcomes in future disease-modifying clinical trials.

Freezing of gait in parkinson’s disease: a perceptual cause for a motor impairment?

Abstract: While freezing of gait (FOG) is typically considered a motor impairment, the fact that it occurs more frequently in confined spaces suggests that perception of space might contribute to FOG. The present study evaluated how doorway size influenced characteristics of gait that might be indicative of freezing. Changes in spatiotemporal aspects of gait were evaluated while walking through three different-sized doorways (narrow (0.675 m wide x 2.1 m high), normal (0.9 m wide x 2.1 m high) and wide (1.8 m wide x 2.1 m high)) in three separate groups: 15 individuals with Parkinson's disease confirmed to be experiencing FOG at the time of test; 16 non-FOG individuals with Parkinson's disease and 16 healthy age-matched control participants. Results for step length indicated that the FOG group was most affected by the narrow doorway and was the only group whose step length was dependent on upcoming doorway size as indicated by a significant interaction of group by condition (F(4,88)=2.73, p<0.034). Importantly, the FOG group also displayed increased within-trial variability of step length and step time, which was exaggerated as doorway size decreased (F(4,88)=2.99, p<0.023). A significant interaction between group and condition for base of support measures indicated that the non-FOG participants were also affected by doorway size (similar to Parkinson's disease FOG) but only in the narrow doorway condition. These results support the notion that some occurrences of freezing may be the result of an underlying perceptual mechanism that interferes with online movement planning.

Measurement instruments to assess posture, gait, and balance in Parkinson's disease: Critique and recommendations

Abstract: BACKGROUND: Disorders of posture, gait, and balance in Parkinson's disease (PD) are common and debilitating. This MDS-commissioned task force assessed clinimetric properties of existing rating scales, questionnaires, and timed tests that assess these features in PD. METHODS: A literature review was conducted. Identified instruments were evaluated systematically and classified as "recommended," "suggested," or "listed." Inclusion of rating scales was restricted to those that could be used readily in clinical research and practice. RESULTS: One rating scale was classified as "recommended" (UPDRS-derived Postural Instability and Gait Difficulty score) and 2 as "suggested" (Tinetti Balance Scale, Rating Scale for Gait Evaluation). Three scales requiring equipment (Berg Balance Scale, Mini-BESTest, Dynamic Gait Index) also fulfilled criteria for "recommended" and 2 for "suggested" (FOG score, Gait and Balance Scale). Four questionnaires were "recommended" (Freezing of Gait Questionnaire, Activities-specific Balance Confidence Scale, Falls Efficacy Scale, Survey of Activities, and Fear of Falling in the Elderly-Modified). Four tests were classified as "recommended" (6-minute and 10-m walk tests, Timed Up-and-Go, Functional Reach). CONCLUSION: We identified several questionnaires that adequately assess freezing of gait and balance confidence in PD and a number of useful clinical tests. However, most clinical rating scales for gait, balance, and posture perform suboptimally or have been evaluated insufficiently. No instrument comprehensively and separately evaluates all relevant PD-specific gait characteristics with good clinimetric properties, and none provides separate balance and gait scores with adequate content validity for PD. We therefore recommend the development of such a PD-specific, easily administered, comprehensive gait and balance scale that separately assesses all relevant constructs. (c) 2016 International Parkinson and Movement Disorder Society.

Symptom and gait changes after sensory attention focused exercise vs aerobic training in Parkinson's disease†

Abstract: The current study compared lower-limb aerobic training and sensory attention focused exercise (PD SAFEx) to a non-exercise control group with the overall objective of determining which strategy would have a greater benefit for Parkinson's disease (PD) symptoms and gait. PD SAFEx was developed to focus on sensorimotor deficits identified in PD with the aim of increasing sensory feedback and body awareness, while the lower-limb aerobic training utilized a specially designed semi-recumbent elliptical device. Intervention groups (PD SAFEx, n = 18; aerobic, n = 13) exercised three times/week for 10-12 weeks, while nonexercise control participants (n = 15) maintained their regular activity level for 12 weeks. Outcome measures included the Unified Parkinson's disease rating scale motor section (UPDRS) administered by a blinded clinician; a posture and gait (PG) score (total of UPDRS items 27-31); the Timed-Up-and-Go (TUG); and spatiotemporal aspects of self-paced gait. PD SAFEx resulted in an improved UPDRS, PG score, and TUG (reached significance when participants with poor attendance were excluded) but not self-paced gait. The lower-limb aerobic training led to increased step length and velocity but had no change to disease severity. Since gait improvements were not combined with symptomatic changes, lower-limb aerobic exercise may not be optimal for individuals with PD. Conversely, sensory-based exercise (PD SAFEx) was beneficial, and led to improvement in symptoms and functional movement control.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

The Movement Disorder Society Evidence-Based Medicine Review Update: Treatments for the non-motor symptoms of Parkinson's disease

Abstract: The Movement Disorder Society (MDS) Task Force on Evidence-Based Medicine (EBM) Review of Treatments for Parkinson's Disease (PD) was first published in 2002 and was updated in 2005 to cover clinical trial data up to January 2004 with the focus on motor symptoms of PD. In this revised version the MDS task force decided it was necessary to extend the review to non-motor symptoms. The objective of this work was to update previous EBM reviews on treat- ments for PD with a focus on non-motor symptoms. Level-I (randomized controlled trial, RCT) reports of pharmacological and nonpharmacological interventions for the non-motor symptoms of PD, published as full

Freezing of gait: Moving forward on a mysterious clinical phenomenon

Abstract: Freezing of gait (FoG) is a unique and disabling clinical phenomenon characterised by brief episodes of inability to step or by extremely short steps that typically occur on initiating gait or on turning while walking. Patients with FoG, which is a feature of parkinsonian syndromes, show variability in gait metrics between FoG episodes and a substantial reduction in step length with frequent trembling of the legs during FoG episodes. Physiological, functional imaging, and clinical-pathological studies point to disturbances in frontal cortical regions, the basal ganglia, and the midbrain locomotor region as the probable origins of FoG. Medications, deep brain stimulation, and rehabilitation techniques can alleviate symptoms of FoG in some patients, but these treatments lack efficacy in patients with advanced FoG. A better understanding of the phenomenon is needed to aid the development of effective therapeutic strategies.