Andrew Duker

Dr. Andrew Duker

orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 April 2011 in Movement Disorders
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Journal Article
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DHDustin A. Heldman
Dustin A. Heldman
JGJoseph P. Giuffrida
Joseph P. Giuffrida
RCRobert Chen
Robert Chen
MPMegan Payne
Megan Payne
FMFilomena Mazzella
Filomena Mazzella
AEAlberto J. Espay
Alberto J. Espay

23 September 2011 in Movement Disorders
Verified
Journal Article
Closed access
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AEAlberto J. Espay
Alberto J. Espay
JGJoe P. Giuffrida
Joe P. Giuffrida
RCRobert Chen
Robert Chen
MPMegan Payne
Megan Payne
FMFilomena Mazzella
Filomena Mazzella
DHDustin A. Heldman
Dustin A. Heldman

1 January 2010 in Journal of Rehabilitation Research and Development
Verified
Journal Article
Closed access
AEAlberto J. Espay
Alberto J. Espay
YBYoram Baram
Yoram Baram
ADAlok Kumar Dwivedi
Alok Kumar Dwivedi
RSRakesh Shukla
Rakesh Shukla
MGMaureen Gartner
Maureen Gartner
FRFredy J. Revilla
Fredy J. Revilla
Shuffling and freezing while walking can impair function in patients with Parkinson disease (PD). Open-loop devices that provide fixed-velocity visual or auditory cues can improve gait but may be unreliable or exacerbate freezing of gait in some patients. We examined the efficacy of a closed-loop, accelerometer-driven, wearable, visual-auditory cueing device in 13 patients with PD with off-state gait impairment at baseline and after 2 weeks of twice daily (30 minute duration) at-home use. We measured gait velocity, stride length, and cadence using a validated electronic gait-analysis system. Subjects underwent standard motor assessment and completed a self-administered Freezing of Gait Questionnaire (FOGQ) (range 0-24; lower is better). After training, device use enhanced walking velocity (61.6 ± 20.1 cm/s to 72.6 ± 26.5 cm/s, p = 0.006) and stride length (74.3 ± 16.4 cm to 84.0 ± 18.5 cm, p = 0.004). Upon device removal, walking velocity (64.5 ± 21.4 cm/s to 75.4 ± 21.5 cm/s, p < 0.001) and stride length (79.0 ± 20.3 cm to 88.8 ± 17.7 cm, p = 0.003) exhibited a greater magnitude of change, suggesting immediate residual benefits. Also upon device removal, nearly 70 percent of subjects improved by at least 20 percent in either walking velocity, stride length, or both. An overall improvement in gait was measured by the FOGQ (14.2 ±1.9 to 12.4 ± 2.5, p = 0.02). Although issues related to compliance and response variability render a definitive interpretation of study outcome difficult, devices using closed-loop sensory feedback appear to be effective and desirable nonpharmacologic interventions to improve walking in selected individuals with PD.

2 October 2012 in Movement Disorders
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Journal Article
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Alfonso FasanoAlfonso Fasano
Alfonso Fasano
AVAnabela Valadas
Anabela Valadas
KBKailash P. Bhatia
Kailash P. Bhatia
LPL.K. Prashanth
L.K. Prashanth
ALAnthony E. Lang
Anthony E. Lang
AEAlberto J. Espay
Alberto J. Espay
The facial phenotype of psychogenic movement disorders has not been fully characterized. Seven tertiary‐referral movement disorders centers using a standardized data collection on a computerized database performed a retrospective chart review of psychogenic movement disorders involving the face. Patients with organic forms of facial dystonia or any medical or neurological disorder known to affect facial muscles were excluded. Sixty‐one patients fulfilled the inclusion criteria for psychogenic facial movement disorders (91.8% females; age: 37.0 ± 11.3 years). Phasic or tonic muscular spasms resembling dystonia were documented in all patients most commonly involving the lips (60.7%), followed by eyelids (50.8%), perinasal region (16.4%), and forehead (9.8%). The most common pattern consisted of tonic, sustained, lateral, and/or downward protrusion of one side of the lower lip with ipsilateral jaw deviation (84.3%). Ipsi‐ or contralateral blepharospasm and excessive platysma contraction occurred in isolation or combined with fixed lip dystonia (60.7%). Spasms were reported as painful in 24.6% of cases. Symptom onset was abrupt in most cases (80.3%), with at least 1 precipitating psychological stress or trauma identified in 57.4%. Associated body regions involved included upper limbs (29.5%), neck (16.4%), lower limbs (16.4%), and trunk (4.9%). There were fluctuations in severity and spontaneous exacerbations and remissions (60%). Prevalent comorbidities included depression (38.0%) and tension headache (26.4%). Fixed jaw and/or lip deviation is a characteristic pattern of psychogenic facial movement disorders, occurring in isolation or in combination with other psychogenic movement disorders or other psychogenic features. © 2012 Movement Disorder Society

5 April 2011 in Neurology
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AEA.J. Espay
A.J. Espay
ADA.K. Dwivedi
A.K. Dwivedi
MPM. Payne
M. Payne
LGL. Gaines
L. Gaines
JVJ.E. Vaughan
J.E. Vaughan
RSR. Shukla
R. Shukla
Background: There is a paucity of therapies for gait impairment in Parkinson disease (PD). Open-label studies have suggested improved gait after treatment with methylphenidate (MPD). Objective: To evaluate the efficacy of MPD for the treatment of gait impairment in PD. Methods: Twenty-seven subjects with PD and moderate gait impairment were screened for this 6-month placebo-controlled, double-blind study. Subjects were randomly assigned to MPD (maximum, up to 80 mg/day) or placebo for 12 weeks and crossed over after a 3-week washout. The primary outcome measure was change in a gait composite score (stride length + velocity) between groups at 4 and 12 weeks. Secondary outcome measures included changes in motor function, as measured by the Unified Parkinson9s Disease Rating Scale (UPDRS), Freezing of Gait Questionnaire (FOGQ), number of gait-diary freezing episodes, and measures of depression, sleepiness, and quality of life. Three-factor repeated-measures analysis of variance was used to measure changes between groups. Results: Twenty-three eligible subjects with PD were randomized and 17 completed the trial. There was no change in the gait composite score or treatment or time effect for any of the variables. Treatment effect was not modified by state or study visit. Although there was a trend for reduced frequency of freezing and shuffling per diary, the FOGQ and UPDRS scores worsened in the MPD group compared to placebo. There was a marginal improvement in some measures of depression. Conclusions: MPD did not improve gait and tended to worsen measures of motor function, sleepiness, and quality of life. Classification of evidence: This study provides Class III evidence for the lack of benefit of MPD on PD-associated gait impairment. Clinical trial registration: NCT00526630.

29 August 2008 in Movement Disorders
Verified
Journal Article
Closed access
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AEAlberto J. Espay
Alberto J. Espay
ADAndrew Duker
Andrew Duker
RCRobert Chen
Robert Chen
MOMichael S. Okun
Michael S. Okun
EBEdwin T. Barrett
Edwin T. Barrett
FRFredy J. Revilla
Fredy J. Revilla