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Visual Function During Gait in Parkinson's Disease: Impact of Cognition and Response to Visual Cues

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ClinicalTrials.gov Identifier: NCT02610634
Recruitment Status : Completed
First Posted : November 20, 2015
Results First Posted : January 30, 2017
Last Update Posted : October 23, 2017
Sponsor:
Collaborator:
Newcastle University
Information provided by (Responsible Party):
Newcastle-upon-Tyne Hospitals NHS Trust

Brief Summary:

Parkinson's disease (PD) is associated with problems of gait such as veering, difficulty turning, an inability to perceive doorways or obstacles, and negotiate uneven terrain. Gait problems, especially veering, may be exacerbated by visuospatial dysfunction which predispose to falls, freezing and festination of gait. Visuospatial dysfunction is common in PD and likely involves peripheral features (e.g. contrast sensitivity) as well as central cognitive mechanisms (e.g. attention).

Central neuro-degeneration in PD, PD dementia, and dementia with Lewy Bodies may influence visual function, as impaired visual sampling has been reported in these conditions. Visual sampling is measured via saccadic (fast eye movement) activity, as saccades are the mechanisms through which people orientate and explore the environment. The use of objective devices to reliably measure saccades is important to detect disease related eye movement changes. Emerging visuomotor research has measured visual sampling in PD using devices such as electrooculography and infra-red eye tracking, revealing reduced amplitude, speed and frequency of saccades during various tasks.

Despite recent increases in visuomotor research it remains unclear how PD influences visual sampling of the environment during gait and the influence of attentional and cognitive deficits. Recent work demonstrated that people with PD sample their environment less frequently than controls, despite a slower gait. Saccadic timing was unchanged in response to environmental cues. Despite this, environmental visual cues (transverse lines on the floor) have been shown to increase the number of fixations made during gait. However the mechanisms of this response remain unclear. Cognition is likely of importance, with response potentially influenced by attentional control.

This observational study aims to examine the influence of cognition on visuomotor control during gait in PD. This aim will be achieved by observation of visual sampling under several environmental challenges (straight walk, doorways, turns, visual cue) and a dual task.


Condition or disease
Parkinson's Disease

  Show Detailed Description

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Study Type : Observational
Actual Enrollment : 100 participants
Observational Model: Case-Control
Time Perspective: Cross-Sectional
Official Title: Visual Function During Gait in Parkinson's Disease: Impact of Cognition and Response to Visual Cues
Study Start Date : July 2013
Actual Primary Completion Date : February 2015
Actual Study Completion Date : February 2015

Resource links provided by the National Library of Medicine


Group/Cohort
Parkinson's disease
People with Parkinson's disease (≥ 50 years old) who do not have dementia (MoCA ≥ 21).
Older Adults
Aged-matched older adults (≥ 50 years old) who are cognitively intact (MoCA ≥26).



Primary Outcome Measures :
  1. Visual Sampling Parameter: Saccade Frequency During Gait [ Time Frame: Session 1: observation during gait assessments (lasting approx. 90mins) ]
    Number of fast eye movements made per second observed when walking, measured via EOG and Dikablis mobile eye-tracker. Walking conditions include; single task, dual task, through a doorway, whilst turning and with a visual cue in place.


Secondary Outcome Measures :
  1. Gait Parameter: Gait Speed [ Time Frame: Session 1: observation during gait assessments (lasting approx. 90mins) ]
    Measured in meters per second observed when walking recorded via Vicon 3D motion capture. Walking conditions include; single task, dual task, through a doorway, whilst turning and with a visual cue in place.

  2. Gait Parameter: Step Length [ Time Frame: Session 1: observation during gait assessments (lasting approx. 90mins) ]
    Measured in meters recorded via Vicon 3D motion capture. Observed during the following walking conditions; single task, dual task, through a doorway, whilst turning and with a visual cue in place.

  3. Gait Parameter: Step Time [ Time Frame: Session 1: observation during gait assessments (lasting approx. 90mins) and one week later in Session 2 for a sub-group (PD and controls n = upto 25) (lasting approx. 60mins) ]
    Measured in seconds recorded via Vicon 3D motion capture. Observed during the following walking conditions; single task, dual task, through a doorway, whilst turning and with a visual cue in place.

  4. Gait Parameter: Single Support Time [ Time Frame: Session 1: observation during gait assessments (lasting approx. 90mins) ]
    Measured in seconds recorded via Vicon 3D motion capture. Observed during the following walking conditions; single task, dual task, through a doorway, whilst turning and with a visual cue in place.

  5. Gait Parameter: Double Support Time [ Time Frame: Session 1: observation during gait assessments (lasting approx. 90mins) ]
    Measured in seconds recorded via Vicon 3D motion capture. Observed during the following walking conditions; single task, dual task, through a doorway, whilst turning and with a visual cue in place.

  6. Visual Sampling Parameter: Saccade Number During Gait [ Time Frame: Session 1: observation during gait assessments (lasting approx. 90mins) and one week later in Session 2 for a sub-group (PD and controls n = upto 25) (lasting approx. 60mins) ]
    Number of fast eye movements observed when walking, measured via EOG and Dikablis mobile eye-tracker. Walking conditions include; single task, dual task, through a doorway, whilst turning and with a visual cue in place.

  7. Visual Sampling Parameter: Saccade Velocity During Gait [ Time Frame: Session 1: observation during gait assessments (lasting approx. 90mins) ]
    Velocity (degrees per second) of fast eye movements observed when walking, measured via EOG and Dikablis mobile eye-tracker. Walking conditions include; single task, dual task, through a doorway, whilst turning and with a visual cue in place.

  8. Visual Sampling Parameter: Saccade Amplitude During Gait [ Time Frame: Session 1: observation during gait assessments (lasting approx. 90mins) ]
    Distance (degrees) of fast eye movements observed when walking, measured via EOG and Dikablis mobile eye-tracker. Walking conditions include; single task, dual task, through a doorway, whilst turning and with a visual cue in place.

  9. Visual Sampling Parameter: Saccade Acceleration During Gait [ Time Frame: Session 1: observation during gait assessments (lasting approx. 90mins) ]
    Acceleration (degrees per second squared) of fast eye movements observed when walking, measured via EOG and Dikablis mobile eye-tracker. Walking conditions include; single task, dual task, through a doorway, whilst turning and with a visual cue in place.

  10. Visual Sampling Parameter: Fixation Number During Gait [ Time Frame: Session 1: observation during gait assessments (lasting approx. 90mins) ]
    Number of pauses (fixations) between fast eye movements observed when walking, measured via EOG and Dikablis mobile eye-tracker. Walking conditions include; single task, dual task, through a doorway, whilst turning and with a visual cue in place.

  11. Visual Sampling Parameter: Fixation Duration During Gait [ Time Frame: Session 1: observation during gait assessments (lasting approx. 90mins) ]
    Duration (ms) of pauses (fixations) between fast eye movements observed when walking, measured via EOG and Dikablis mobile eye-tracker. Walking conditions include; single task, dual task, through a doorway, whilst turning and with a visual cue in place.

  12. Visual Sampling Parameter: Saccade Duration During Gait [ Time Frame: Session 1: observation during gait assessments (lasting approx. 90mins) ]
    Duration (ms) of fast eye movements observed when walking, measured via EOG and Dikablis mobile eye-tracker. Walking conditions include; single task, dual task, through a doorway, whilst turning and with a visual cue in place.

  13. Visual Sampling Parameter: Number of Blinks During Gait [ Time Frame: Session 1: observation during gait assessments (lasting approx. 90mins) and one week later in Session 2 for a sub-group (PD and controls n = upto 25) (lasting approx. 60mins) ]
    Number of blinks observed when walking, measured via EOG and Dikablis mobile eye-tracker. Walking conditions include; single task, dual task, through a doorway, whilst turning and with a visual cue in place.


Other Outcome Measures:
  1. CDR Attention Battery (Cognitive Drug Research - CDR, United Biosource Corporation, UK) [ Time Frame: Session 1 (full session lasts approx. 3 hours) ]
    The Attention CDR involves a series of computerised tests, which the subjects respond to by pressing one of two buttons. Scores for sub-sections of Simple reaction time, Digit vigilance and Choice reaction time will be obtained.

  2. Benton's Judgement of Line Orientation (JLO) Test [ Time Frame: Session 1 (full session lasts approx. 3 hours) ]
    JLO is a test of visuospatial ability, which involves a subject viewing a set of numbered lines and then being shown two lines of the same orientation. Participants then have to name the numbers that the shown lines correspond to.

  3. Clock Copying (CLOX 1 and 2) [ Time Frame: Session 1 (full session lasts approx. 3 hours) ]
    Participants are required to draw a clock with the numbers and arrows pointed at a particular time. Then the subjects have to copy a clock drawn by the researcher.

  4. Visual Object and Space Perception Battery (VOSP) [ Time Frame: Session 1 (full session lasts approx. 3 hours) ]
    This study will use a selection of these tests; incomplete letters, dot counting and position discrimination.

  5. Visual Acuity [ Time Frame: Session 1 (full session lasts approx. 3 hours) ]
    VA is measured binocularly used a standard LogMAR chart. Participants will be seated at a distance of 4m from the chart. Participants will be instructed to read aloud down the chart starting from the top left.

  6. Contrast Sensitivity [ Time Frame: Session 1 (full session lasts approx. 3 hours) ]
    CS will be measured using the Mars CS sheets placed on an adjustable holder. The sheet consists of 48 Latin letters of uniform height; the contrast from the white background decreases with subsequent letters. Room illumination is adjusted so that average CS sheet luminance is between 80 and 120cd/m² (measured via a luminance meter). Assessment is done binocularly with the average distance from the patients eyes being 50cm. Participants read aloud down the sheet starting at the top left. Errors are recorded on the pre-set score sheet and testing is terminated after 2 consecutive errors.

  7. The Unified Parkinson's Disease Rating Scale (UPDRS) [ Time Frame: Session 1 (full session lasts approx. 3 hours) ]
    The Unified Parkinson's Disease Rating Scale will be used to assess motor and non-motor features of PD and disease severity. The UPDRS is scored from a total of 195 points; higher scores reflect worsening disability.

  8. Hoehn & Yahr (H & Y) Scale [ Time Frame: Session 1 (full session lasts approx. 3 hours) ]
    The Hoehn and Yahr rating scale is a widely used clinical rating scale, which defines broad categories of motor function in Parkinson's disease (PD). All participants' will be tested who are in H &Y stages I-III.

  9. Freezing of Gait (FOG) Questionnaire [ Time Frame: Session 1 (full session lasts approx. 3 hours) ]
    This is a 10 item questionnaire intended to classify freezing of gait. The questionnaire has 3 parts; distinction of freezers from non-freezers, Freezing severity, frequency and duration and impact of freezing on daily life.

  10. Falls Efficacy Scale - International (FES-I) [ Time Frame: Session 1 (full session lasts approx. 3 hours) ]
    Fear of falling will be measured using the falls efficacy scale - international version. This is a short and valid measure of fear of falling in older adults, which assesses basic and demanding activities (both physical and social). It consists of 16 scenarios (e.g. cleaning the house) and subjects must rate their fear of falling on a scale from 1 (Not at all concerned) to 4 (Very concerned).

  11. Montreal Cognitive Assessment (MoCA) [ Time Frame: Session 1 (full session lasts approx. 3 hours) ]
    Different cognitive domains are assessed (attention and concentration, executive functions, memory, language, visuo-constructional skills, conceptual thinking, calculations, and orientation).

  12. Addenbrookes Cognitive Examination (ACE-R) [ Time Frame: Session 1 (full session lasts approx. 3 hours) ]
    The ACE-R involves testing of attention, orientation, memory, fluency, language and visuospatial abilities.

  13. Geriatric Depression Scale (GDS-15) [ Time Frame: Session 1 (full session lasts approx. 3 hours) ]
    This involves 15 questions about the mood of the subjects. Scores of 0 to 4 to be in the normal range, 5 to 9 to indicate mild depression, and 10 to 15 to indicate moderate to severe depression.



Information from the National Library of Medicine

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Ages Eligible for Study:   50 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

Parkinson's disease participants will be recruited from Movement Disorder Clinics in Newcastle upon-Tyne.

Healthy control older adults will be recruited locally within the Newcastle upon Tyne region.

Criteria

Inclusion Criteria:

Common to all groups

  • Aged ≥50 years
  • Able to walk unaided
  • Adequate hearing (as evaluated by the whisper test; stand 2m behind participant and whisper a 2 syllable word, participant repeats word) and vision capabilities (as measured using a Snellen chart - 6/18-6/12).
  • Stable medication for the past 1 month and anticipated over a period of 6 months

Group Specific Criteria

Participants with PD:

  • Diagnosis of idiopathic PD, as defined by the UK Brain Bank criteria
  • Hoehn and Yahr stage I-III
  • Stable medication for past 1 month and anticipated over next 6 months or stable Deep Brain Stimulation for at least one month and expected following 6 months
  • Score ≥21/30 on Montreal cognitive assessment (MoCA) which is used to classify non-demented PD (PD dementia is <21/30)
  • Free from any neurological disorders that may have caused cognitive impairment
  • No restriction was made for medication usage and participants on stable doses of medication or treatment were permitted.

Exclusion Criteria:

Common to all groups

  • Psychiatric co-morbidity (e.g., major depressive disorder as determined by geriatric depression scale (GDS-15); >10/15)
  • Clinical diagnosis of dementia or other severe cognitive impairment (PD = MoCA <21/30, Controls = MoCA <26/30)
  • History of stroke, traumatic brain injury or other neurological disorders (other than PD, for that group)
  • Acute lower back or lower extremity pain, peripheral neuropathy, rheumatic and orthopaedic diseases
  • Unstable medical condition including cardio-vascular instability in the past 6 months
  • Unable to comply with the testing protocol or currently participating in another interfering research project
  • Interfering therapy

Vision specific Criteria

  • Any pupillary diameter disorder; such as significantly non-round pupils, Adies pupil (tonic or dilated pupil), Argyll-Robertson pupil (absence of light reaction), unilateral small pupil
  • Neuromotility disorders, such as Nystagmus or other ocular oscillations
  • Significant left eye disorders (i.e. squint, twitching, Ptosis [drooping eyelids])
  • Known significant visual field deficits; such as hemianopia
  • Optic nerve disease
  • Optic disc elevation
  • Optic disc swelling; such as Papilledema or Papillitis

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02610634


Locations
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United Kingdom
Clinical Ageing Research Unit
Newcastle upon Tyne, United Kingdom, NE4 5PL
Sponsors and Collaborators
Newcastle-upon-Tyne Hospitals NHS Trust
Newcastle University
Investigators
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Principal Investigator: Lynn Rochester, PhD Newcastle University

Publications of Results:
Other Publications:
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Responsible Party: Newcastle-upon-Tyne Hospitals NHS Trust
ClinicalTrials.gov Identifier: NCT02610634     History of Changes
Other Study ID Numbers: 6601
CLRN ( Other Identifier: 125425 )
REC number ( Other Identifier: 13/NE/0128 )
First Posted: November 20, 2015    Key Record Dates
Results First Posted: January 30, 2017
Last Update Posted: October 23, 2017
Last Verified: September 2017

Keywords provided by Newcastle-upon-Tyne Hospitals NHS Trust:
Parkinson's disease
Older adults
Vision
Cognition
Visual cues
Eye-tracking
Gait
Saccades
Dual task
Visual sampling

Additional relevant MeSH terms:
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Parkinson Disease
Parkinsonian Disorders
Basal Ganglia Diseases
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Movement Disorders
Neurodegenerative Diseases