Jean-Michel Gracies

Mount Sinai Medical Center, New York City, New York, United States

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Publications (35)80.22 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine the efficacy and safety of 2 doses of botulinum toxin type B (rimabotulinumtoxinB, BoNT/B) in spastic upper limb muscles. Randomized, double-blind, placebo-controlled trial with a 3-month follow-up SETTING: Tertiary care center PARTICIPANTS: Referred sample of 24 adult hemiparetic patients with disabling elbow flexor overactivity after stroke or traumatic brain injury. Injection of 10,000U of rimabotulinumtoxinB (fixed 2500U dose into elbow flexors; n=8), 15,000U (5000U into elbow flexors; n =8), or placebo (n=8), into overactive upper limb muscles selected as per investigator's discretion. At 1 month post-injection, active range of elbow extension (goniometry; primary outcome); active upper limb function (Modified Frenchay Scale, MFS); subjective global self-assessment (GSA) of arm pain, stiffness, and function; rapid alternating elbow flexion-extension movement frequency over the maximal range; elbow flexor spasticity grade and angle (Tardieu), and tone (Ashworth). No adverse effects were associated with either BoNT/B dose. Both doses improved active elbow extension vs placebo (+8.3°, 95%CI [1.1-15.5°], p=0.028, ANCOVA). The high dose of BoNT/B also improved subject-perceived stiffness (p=0.005) and the composite pain, stiffness and function GSA (p=0.017), effects that persisted 3 months from injection. No MFS change was demonstrated although subjects with baseline MFS <70/100 seemed more likely to benefit from BoNT/B. In this short-term study, BoNT/B up to 15,000U into spastic upper limb muscles including elbow flexors, was well tolerated and improved active elbow extension and subject-perceived stiffness.
    Archives of physical medicine and rehabilitation 04/2014; · 2.18 Impact Factor
  • Clinical neurophysiology: official journal of the International Federation of Clinical Neurophysiology 12/2013; · 3.12 Impact Factor
  • Muscle & Nerve 11/2013; · 2.31 Impact Factor
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    ABSTRACT: OBJECTIVE: Spastic co-contraction is a misdirected supraspinal command in spastic paresis. We quantified the influence of effort and gastrocnemius stretch on plantar flexor co-contraction and torque during dorsiflexion efforts in hemiparetic and healthy subjects. METHODS: Eighteen healthy and 18 hemiparetic subjects produced "light", "medium" and "maximal" isometric dorsi- and plantar flexion efforts in two gastrocnemius positions, stretched (knee extended) and slack (knee flexed), ankle at 90°. Measuring ankle torque and soleus and medial gastrocnemius surface EMG, we calculated the co-contraction index (CCI) as the ratio of the EMG root mean square (RMS) from the muscle acting as antagonist over its RMS when acting as agonist in a maximal effort, in each knee position. RESULTS: Co-contraction was abnormally high in hemiparetic subjects at all effort levels, e.g. for soleus in the knee extended position (CCI(SO) 0.37±0.08 in hemiparesis vs 0.18±0.02 in healthy subjects, p<0.05). In hemiparetic subjects knee extended, dorsiflexion torque, (i) was reversed or canceled in 26% trials; and (ii) correlated negatively with plantar flexor CCI. SIGNIFICANCE: Major dynamometric impact of co-contraction with stretched position of the cocontracting muscle may justify muscle length modifications (e.g. through aggressive stretch programs) to improve function in spastic paresis.
    Clinical neurophysiology: official journal of the International Federation of Clinical Neurophysiology 10/2012; · 3.12 Impact Factor
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    ABSTRACT: Gait training at fast speed has been suggested as an efficient rehabilitation method in hemiparesis. We investigated whether maximal speed walking might positively impact inter-segmental coordination in hemiparetic subjects. We measured thigh-shank and shank-foot coordination in the sagittal plane during gait at preferred (P) and maximal (M) speed using the continuous relative phase (CRP), in 20 healthy and 27 hemiparetic subjects. We calculated the root-mean square (CRP(RMS)) and its variability (CRP(SD)) over each phase of the gait cycle. A small CRP(RMS) indicates in-phasing, i.e. high level of synchronization between two segments along the gait cycle. A small CRP(SD) indicates high stability of the inter-segmental coordination across gait cycles. Increase from preferred to maximal speed was 57% in healthy and 49% in hemiparetic subjects (difference NS). In healthy subjects, the main change was shank-foot in-phasing at stance (CRP(Shank-Foot/RMS), P, 98±10; M, 67±12, p<0.001). In hemiparetic subjects, we also found shank-foot in-phasing at late stance bilaterally (non-paretic CRP(Shank-Foot/RMS), P, 37±9; M, 29±8, p<0.001; paretic CRP(Shank-Foot/RMS), P, 38±13; M, 32±12, p<0.001), and thigh-shank in-phasing at mid-stance in the non-paretic limb (CRP(Thigh-Shank/RMS), P, 57±9; M, 49±9, p<0.001). CRP(Thigh-Shank) variability diminished in the paretic limb (CRP(Thigh-Shank/SD), P, 18.3±6.3; M, 16.1±5.2, p<0.001). During gait velocity increase in hemiparesis, there is improvement of thigh-shank coordination stability in the paretic limb and of shank-foot synchronization at late stance bilaterally, which optimizes the propulsive phase similarly to healthy subjects. These findings may add incentive for rehabilitation clinicians to explore maximal velocity gait training in hemiparesis.
    Gait & posture 04/2012; 36(2):205-11. · 2.58 Impact Factor
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    ABSTRACT: Introduction: In this study of spastic hemiparesis we evaluated cocontraction during sustained agonist/antagonist efforts, before and after botulinum toxin (BoNT) injection in 1 agonist. Methods: Nineteen hemiparetic subjects performed maximal isometric elbow flexion/extension efforts with the elbow at 100° (extensors stretched). Using flexor and extensor surface electromyography we calculated agonist recruitment/cocontraction indices from 500-ms peak voluntary agonist recruitment, before and 1 month after onabotulinumtoxinA injection (160 U) into biceps brachii. Results: Before injection, agonist recruitment and cocontraction indices were higher in extensors than flexors [0.74 ± 0.15 vs. 0.59 ± 0.10 (P < 0.01) and 0.43 ± 0.25 vs. 0.25 ± 0.13 (P < 0.05), respectively]. Biceps injection decreased extensor cocontraction index (-35%, P < 0.05) while increasing flexor agonist recruitment and cocontraction indices. Conclusions: In spastic hemiparesis, stretch may facilitate agonist recruitment and spastic cocontraction. In the non-injected antagonist, cocontraction may be reduced by enhanced reciprocal inhibition from a more relaxed, and therefore stretched, agonist, or through decreased recurrent inhibition from the injected muscle. Muscle Nerve, 2012.
    Muscle & Nerve 04/2012; · 2.31 Impact Factor
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    ABSTRACT: To examine the safety and efficacy of onabotulinumtoxinA (Botox) for plantarflexor overactivity following stroke. Double-blind randomized controlled trial, open-label extension phase. Neurology rehabilitation facilities. Eighty-five subjects with lower limb hypertonia received 200 U (n = 28) or 300 U (n = 28) of onabotulinumtoxinA or saline (n = 29) injection. Plantarflexor Ashworth scores at 12 weeks post injection and adverse events. Secondary measures: self-reported spasm frequency and pain, physician rating of hypertonia severity, gait quality and active dorsiflexion. Differences were not seen between onabotulinumtoxinA groups; hence data were pooled. Incidence of adverse events was not different between groups (P = 0.61). Reduction in hypertonia was not different between groups at 12 weeks (P = 0.53); however for subjects with Ashworth scores of >3 at baseline, 14/31 in the onabotulinumtoxinA group demonstrated a reduction of >1 grade versus 1/17 receiving placebo injection (P = 0.01). Overall, onabotulinumtoxinA-injected subjects demonstrated significantly greater improvement in spasm frequency (22/54 versus 4/29, P = 0.01), pain reduction (8/54 versus 1/29, P = 0.02), active dorsiflexion (8/54 versus 1/29 P = 0.03) and gait quality (17/54 versus 6/29, P = 0.02) than controls. In the open-label phase, a second onabotulinumtoxinA injection was associated with greater hypertonia reduction (P = 0.005) and gait quality (P = 0.002) compared with single injection. OnabotulinumtoxinA injection for ankle flexor overactivity after stroke was safe and well tolerated but did not alter local spasticity at 12 weeks; it did reduce spasms and improve gait quality. There were no detectable differences between higher and lower doses. A second injection may be associated with greater change.
    Clinical Rehabilitation 02/2012; 26(9):787-97. · 2.19 Impact Factor
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    ABSTRACT: Consistent with the hypothesis that dopamine is implicated in the processing of salient stimuli relevant to the modification of various behavioral responses, Parkinson's disease is associated with emotional blunting. To address the hypothesis that emotional attention and memory are modulated by dopaminergic neurotransmission in Parkinson's disease, we assessed 15 nondemented patients with Parkinson's disease while on and off dopaminergic medication and 15 age-matched healthy controls. Visual stimuli were presented, and recognition was used to assess emotional memory. Response latency was used as a measure of emotional attention modulation. Stimuli were varied based on valence (pleasant, neutral, and unpleasant) and arousal (high and low) dimensions. Controls had significantly better memory for positive than negative stimuli, whereas patients with Parkinson's disease tested off medication had significantly better memory for negative than positive items. This negativity bias was lost when they were tested while on dopaminergic medication. Reaction times in patients with Parkinson's disease off medication were longer than in healthy controls and, paradoxically, were even longer when on medication. Further, although both healthy controls and patients with Parkinson's disease in the "off" state had arousal-induced prolongation of reaction time, this effect was not seen in patients with Parkinson's disease on medication. These data indicate that dopaminergic neurotransmission is implicated in emotional memory and attention and suggest that dopamine mediates emotional memory via the valence dimension and emotional attention via arousal. Furthermore, our findings suggest that emotional changes in Parkinson's disease result from the effects of both the disease process and dopaminergic treatment.
    Movement Disorders 06/2011; 26(9):1677-83. · 5.63 Impact Factor
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    ABSTRACT: Whereas aging affects cognitive and psychomotor processes negatively, the impact of aging on emotional processing is less clear. Using an "old-new" binary decision task, we ascertained the modulation of response latencies after presentation of neutral and emotional pictures in "young" (M = 27.1 years) and "young-old" adults with a mean age below 60 (M = 57.7 years). Stimuli varied on valence (pleasant, neutral, and unpleasant) and arousal (high and low) dimensions. Young-old adults had significantly longer reaction times. However, young and young-old adults showed the exact same pattern of response time modulation by emotional stimuli: Response latencies were longer for high-arousal than for low-arousal pictures and longer for negative than for positive or neutral stimuli. This result suggests that the specific effects of implicitly processed emotional valence and arousal information on behavioral response time are preserved in young-old adults despite significant age-related psychomotor decline.
    The International journal of neuroscience 05/2011; 121(8):430-6. · 0.86 Impact Factor
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    ABSTRACT: Emotions can affect various aspects of human behavior. The impact of emotions on behavior is traditionally thought to occur at central, cognitive and motor preparation stages. Using EMG to measure the effects of emotion on movement, we found that emotional stimuli differing in valence and arousal elicited highly specific effects on peripheral movement time. This result has conceptual implications for the emotion-motion link and potentially practical implications for neurorehabilitation and professional environments where fast motor reactions are critical.
    Journal of Neural Transmission 04/2011; 118(9):1319-22. · 3.05 Impact Factor
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    ABSTRACT: The mechanisms altering knee flexion in hemiparetic gait may be neurological (muscle overactivity) or orthopedic (soft tissue contracture) in nature, a distinction which is difficult to ascertain clinically during gait. This study aimed to distinguish the 2 mechanisms in evaluating thigh-shank coordination, which may show instability across the gait cycle in the case of bursting rectus femoris overactivity. We measured thigh-shank coordination in the sagittal plane using the continuous relative phase during gait in 15 healthy subjects without and with an orthotic knee constraint (control and constrained) and 14 subjects with hemiparesis and rectus femoris overactivity before (pre) and after botulinum toxin injection. Compared with the control group, both orthopedic and neurological knee flexion limitations were associated with decreased root-mean square of continuous relative phase over swing (control, 72.9; constrained, 26.0, P<0.001; pre, 31.3, P<0.001). However, only the neurological limitation was characterized by a higher number of continuous relative phase reversals over swing (control, 2.3; pre, 4.0; P=0.001) and late stance (control, 0.6; pre, 1.7; P<0.001). Botulinum toxin injection was associated with a 40% increase in root-mean square of continuous relative phase during swing and a 41% decrease in number of continuous relative phase reversals during late stance, while peak knee flexion was increased by 31%. In hemiparesis, rectus femoris overactivity at swing phase is associated with alternating thigh-shank coordination in swing and late stance, which improves after botulinum toxin injection. Coordination analysis may help to distinguish neurological from orthopedic factors in knee flexion impairment.
    Clinical biomechanics (Bristol, Avon) 11/2010; 26(3):304-11. · 1.76 Impact Factor
  • Jean-Michel Gracies, N Bayle, M Vinti, S Alkandari, P Vu, C M Loche, C Colas
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    ABSTRACT: Among the three main factors of motor impairment that emerge in chronological order following a lesion to central motor pathways, the last two antagonize movement: 1) stretch-sensitive paresis, a reduction of agonist motor unit recruitment upon voluntary command, worsened by antagonist stretch; 2) soft tissue contracture, and 3) muscle overactivity. Types of muscle overactivity include 1) spasticity, an increase in the velocity-dependent response to muscle stretch, measured at rest; 2) spastic dystonia, i.e., chronic tonic muscle activity at rest, sensitive to stretch of the dystonic muscle and 3) spastic co-contraction, an inappropriate degree of antagonistic contraction during voluntary agonist command, sensitive to stretch of the co-contracting muscle. A five-step clinical assessment may closely parallel this phenomenology, in which the first four steps aim at quantifying the antagonistic potential of each muscle group. Step-1 measures passive range of motion, i.e., the angle of arrest upon slow stretch of the muscle group assessed (minimizing spastic dystonia), which provides insight on soft tissue length and extensibility. Step-2 measures the angle of catch or clonus upon fast passive stretch of the muscle group assessed, which provides insight on stretch reflex excitability. Step-3 measures the range of active motion against the muscle group assessed, a net result of agonist recruitment minus the combined resistance from passive soft tissue stiffness and spastic co-contraction in the muscle group assessed. Step-4 measures the maximal frequency of rapid alternating movements along the maximal active range of motion, evaluating Step-3 performance repeatability. Step-5 evaluates active function, using for example a walking test (10 m or 2 min) for lower limb and the Modified Frenchay Scale for upper limb assessment, and perceived function through patient global subjective assessment.
    European journal of physical and rehabilitation medicine 09/2010; 46(3):411-21. · 2.06 Impact Factor
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    ABSTRACT: Botulinum toxin (BTX) injection into rectus femoris (RF) is a therapeutic modality used to improve knee flexion during the swing phase of gait in hemiparesis. The impact of this treatment on lower limb coordination is unknown. The authors evaluated whether BTX injection into RF is associated with modifications of intersegmental coordination in hemiparesis. The authors evaluated gait in 10 control and 14 hemiparetic subjects with low peak knee flexion associated with inappropriate RF activity in mid-swing, using 3-dimensional analysis before and 1 month after BTX injection into RF (Botox, 200 units). Thigh-shank coordination was measured in the sagittal plane by averaging the continuous relative phase (CRP(Thigh-Shank)) during each phase of the gait cycle in both lower limbs. The CRP is a validated metric that integrates angle positions and velocities of 2 limb segments to quantify their temporal-spatial coordination. Before treatment, the low peak knee flexion in hemiparetic subjects (paretic limb 29 +/- 9 degrees) was associated with a decreased CRP(Thigh-Shank) in the paretic limb in swing (paretic limb 26.0 +/- 16.6 degrees vs controls 73.5 +/- 7.4 degrees, P < .001) and with a trend of an increased CRP(Thigh-Shank) in the nonparetic limb over the full gait cycle (nonparetic limb 77.9 +/- 14.1 degrees vs controls 66.2 +/- 19.8 degrees, P = .083). After treatment, the CRP(Thigh-Shank) increased by 11.9 degrees in the swing phase of the paretic limb (P = .002) and decreased by 8.0 degrees over the full gait cycle ( P = .002) in the nonparetic limb. BTX injection into RF was associated with improved thigh-shank coordination in parts of the gait cycle, in both injected paretic and noninjected nonparetic limbs.
    Neurorehabilitation and neural repair 03/2010; 24(5):442-9. · 4.28 Impact Factor
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    ABSTRACT: To measure the Tardieu Scale's reliability in children with cerebral palsy (CP) when used by raters with and without experience in using the scale, before and after training. Single-center, intrarater and interrater reliability study. Institutional ambulatory care. Referred children with CP in the pretraining phase (n=5), during training (n=3), and in the posttraining phase (n=15). The Tardieu Scale involves performing passive muscle stretch at 2 velocities, slow and fast. The rater derives 2 parameters; the Spasticity Angle X is the difference between the angles of arrest at slow speed and of catch-and-release or clonus at fast speed; the Spasticity Grade Y is an ordinal variable that grades the intensity (gain) of the muscle reaction to fast stretch. In phase 1, experienced raters without formalized training in the scale graded elbow, knee, and ankle plantar flexors bilaterally, without and with a goniometer. In phase 2, after training, the experienced and nonexperienced raters graded the same muscles unilaterally. Intrarater and interrater reliability of the Tardieu Scale. After training, nonexperienced raters had mean +/- SD intrarater and interrater agreement rates across all joints and parameters of 80%+/-14% and 74%+/-16%, respectively. For experienced raters, intrarater and interrater agreement rates before training were 77%+/-13% and 66%+/-15%, respectively, versus 90%+/-8% and 81%+/-13%, respectively, after training (P<.001 for both). Specific angle measurements at the knee were less reliable for the angles of catch measured at fast speed. Across all joints, agreement rates were similar using visual or goniometric measurements. Both parameters of the Tardieu Scale have excellent intrarater and interrater reliability when assessed at the elbow and ankle joints of children with CP, with no difference noted between visual and goniometric measurements. Angle measurements were less reliable at the knee joints. Training was associated with a highly significant improvement in reliability.
    Archives of physical medicine and rehabilitation 03/2010; 91(3):421-8. · 2.18 Impact Factor
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    ABSTRACT: A group of clinicians from across Europe experienced in the use of botulinum toxin type A for the treatment of spasticity following acquired brain injury gathered to develop a consensus statement on best practice in managing adults with spasticity. This consensus table summarizes the current published data, which was collated following extensive literature searches, their assessment for level of evidence and discussion among the whole group. Published information is supplemented by expert opinion based on clinical experience from 16 European countries, involving 28 clinicians, who treat an average of approximately 200 patients annually, representing many thousand spasticity treatments with botulinum toxin per year.
    Journal of rehabilitation medicine: official journal of the UEMS European Board of Physical and Rehabilitation Medicine 02/2009; 41(1):13-25. · 1.88 Impact Factor
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    ABSTRACT: To determine the effects of botulinum neurotoxin type A (BTX-A) dilution and endplate-targeting in spastic elbow flexors. Double blind randomized controlled trial; 4-month follow-up after a 160-unit injection of BTX-A into spastic biceps brachii (4 sites). Randomization into: group 1: 100 mouse units (MU)/mL dilution, 0.4cc/site, 4-quadrant injection; group 2: 100MU/mL dilution, 0.4cc/site, 4 sites along endplate band; group 3: 20MU/mL dilution, 2cc/site, 4-quadrant injection (n=7 per group). Institutional tertiary care ambulatory clinic. Referred sample of 21 adults with spastic hemiparesis. No participant withdrew due to adverse effects. A 160-unit injection of BTX-A of different dilutions and locations into biceps brachii. Primary: agonist and antagonist (cocontraction) mean rectified voltage (MRV) of elbow flexors/extensors during maximal isometric flexion/extension; secondary: maximal voluntary power of elbow flexion/extension; spasticity angle and grade in elbow flexors/extensors (Tardieu Scale); active range of elbow extension/flexion. BTX-A injection overall reduced agonist flexor MRV (-47.5%, P<0.0001), antagonist flexor MRV (-12%, P=.037), antagonist extensor MRV (-19%, P<.01), flexion maximal voluntary power (-33%, P<.001), elbow flexor spasticity angle (-30%, P<.001) and grade (-17%, P=.03), and increased extension maximal voluntary power (24%, P=.037) and active range of elbow extension (5.5%, 8 degrees , P=.002). Agonist and antagonist flexor MRV reductions in group 3 (-81% and -31%) were greater than in groups 1 and 2, whereas increase in active range of elbow extension was greater in group 2 (10%) than in groups 1 and 3 (P<.05, analysis of covariance [ANCOVA]). Elbow flexor spasticity was significantly reduced in groups 2 and 3 only (P<.05, ANCOVA). In spastic biceps, high-volume or endplate-targeted BTX-A injections achieve greater neuromuscular blockade, cocontraction and spasticity reduction, and active range of elbow extension improvement, than low volume, nontargeted injections.
    Archives of physical medicine and rehabilitation 01/2009; 90(1):9-16.e2. · 2.18 Impact Factor
  • Archives of Physical Medicine and Rehabilitation - ARCH PHYS MED REHABIL. 01/2009; 90(10).
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    ABSTRACT: To determine the effects of dopaminergic medication withdrawal in an elderly, demented and minimally ambulatory nursing home population with parkinsonism in New York City. In our double-blind, randomized study, 11 patients (7 males, 4 females) were randomized into 2 groups: one group underwent levodopa medication withdrawal (experimental group) and the other group continued on their levodopa (control group). Patients were evaluated weekly over the course of a month with a neurologic examination and a series of assessment tools, including the motor UPDRS (Unified Parkinson's disease rating scale), Hoehn and Yahr staging scale, the Mini-Mental State Examination (MMSE) and the Nursing Assistant Behavioral Detection Form. An academic nursing home in New York City. The patients had a mean age of 82.00 +/- 10.14 years, with a mean MMSE score of 9.50 +/- 6.60 out of 30.00 maximum. The control and experimental groups did not differ significantly with respect to age (P = .52), dementia severity (P = .35), nor severity of PD symptoms as measured by the UPDRS (P = .22) and Hoehn and Yahr staging (P = .65). Overall, no significant changes were observed between the control and experimental groups in cognitive, behavioral, and motor function across each time period. Of interest, 2 of the drug withdrawal patients showed modest improvements in cognitive function as measured by the MMSE. Our findings suggest that in patients with advanced parkinsonism and dementia, dopaminergic medication withdrawal may be a feasible way to reduce polypharmacy and potential medication-related side effects, with a minimal risk of worsening motor deterioration. Therefore, our findings may have potential implications for a medication intervention that could prevent potential deleterious side effects and improve health-related quality of life in this frail population.
    Journal of the American Medical Directors Association 12/2008; 9(9):670-5. · 5.30 Impact Factor
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    ABSTRACT: The aim of this study was to assess the effect of dopaminergic treatment on emotional memory in patients with Parkinson's disease (PD). We tested memory for emotional and neutral visual stimuli in ten non-demented PD patients on and off dopaminergic medication. Patients recalled significantly more emotional items during the off- than on-medication testing session. In contrast, treatment condition did not affect memory for neutral items. These findings demonstrate that emotional memory deficits observed in PD may result from dopaminergic treatment and suggest an involvement of dopaminergic neurotransmission in emotional processing.
    Journal of Neural Transmission 06/2008; 115(8):1159-63. · 3.05 Impact Factor
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    ABSTRACT: The aim of this study was to quantify the dynamic response of locomotion to the first oral levodopa administration of the day in patients with fluctuating Parkinson's disease (PD). Stride length, walking speed, cadence and gait variability were measured with an ambulatory gait monitor in 13 PD patients (8 males) with a clinical history of motor fluctuations. The Unified Parkinson's Disease Rating Scale (UPDRS) gait score (part 29) was also determined by a movement disorders specialist from video recordings. Subjects arrived in the morning in an 'off' state (no PD medication) and walked for a maximum length of 100 m. They then took their usual morning dose of oral levodopa and repeated the walking task at 13 min intervals (on average) over a 90 min period. Changes in stride length over time were fit with a Hill (Emax) function. Latency (time until stride length increased 15% of the difference between baseline and maximum response) and the Hill coefficient (shape of the 'off-on' transition) were determined from the fitted curve. Latency varied from 4.7 to 53.3 min post-administration [23.31 min (SD 14.9)], and was inversely correlated with age at onset of PD (R = -0.83; P = 0.0004). The Hill coefficient (H) ranged from a smooth hyperbolic curve (0.9) to an abrupt 'off-on' transition (16.9), with a mean of 8.1 (SD 4.9). H correlated with disease duration (R = 0.67; P = 0.01) and latency (R = 0.67; P = 0.01), and increased with Hoehn & Yahr stage in the 'off' state (P = 0.02) from 5.7 (SD 3.5) (H&Y III) to 11.9 (SD 4.7) (H&Y IV). Walking speed correlated with changes in mean stride length, whereas cadence and gait variability did not. UPDRS gait score also reflected improving gait in the majority of subjects (8), providing clinical confirmation of the objective measures of the locomotor response to levodopa. Increasing abruptness (H) of the 'off-on' transition with disease duration is consistent with results from finger-tapping studies, and may reflect reduced buffering capacity of pre-synaptic nigrostriatal dopaminergic neurons. Ambulatory monitoring of gait objectively measures the dynamic locomotor response to levodopa, and this information could be used to improve daily management of motor fluctuations.
    Experimental Brain Research 02/2008; 184(4):469-78. · 2.22 Impact Factor

Publication Stats

604 Citations
80.22 Total Impact Points

Institutions

  • 2004–2014
    • Mount Sinai Medical Center
      New York City, New York, United States
  • 2012
    • Université Paris-Est Créteil Val de Marne - Université Paris 12
      Créteil, Île-de-France, France
  • 2010–2012
    • Assistance Publique – Hôpitaux de Paris
      Lutetia Parisorum, Île-de-France, France
    • Hôpital Henri Mondor (Hôpitaux Universitaires Henri Mondor)
      Créteil, Île-de-France, France
  • 2008–2011
    • Mount Sinai School of Medicine
      • • Department of Neurology
      • • Department of Otolaryngology
      Manhattan, NY, United States
    • L’Institut Régional de Médecine Physique et de Réadaptation
      Nancy, Lorraine, France