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Computer-assisted cognitive rehabilitation on freezing of gait in Parkinson’s disease: A pilot study

BACKGROUND In Parkinsons Disease (PD), effects of a cognitive training have been systematically evaluated only for cognitive and behavioral outcome measures, with mild to moderate effects. Despite the demonstrated interplay between cognition and gait, no studies have investigated the effect of cognitive rehabilitation protocols on gait in PD. METHODS Patients affected by PD with freezing of gait were treated twice a week for six weeks with one hour sessions of computer-assisted training of attention ability and information processing tasks. Gait parameters were recorded at baseline, after six weeks and at three months. RESULTS Seven patients completed the evaluations at six weeks, six patients at three months. We observed at six weeks a significant reduction in both legs cycle duration, with an increment in mean velocity and cadence. Bilateral cycle and step lengths increased even if not significantly. No significant differences in gait parameters were detected at three months with respect to the baseline. CONCLUSIONS This pilot study suggests that a computer-assisted rehabilitation protocol based on executive functions training could improve walking in PD patients with freezing of gait.

Electroencephalographic lateralization, clinical correlates and pharmacological response in untreated Parkinson's disease

BACKGROUND In Parkinsons disease (PD), different topographically defined cortical-subcortical oscillatory networks have been implicated in motor program dysfunction. Few studies have focused on clinical correlates of cortical activity asymmetry using quantitative electroencephalography. METHODS We retrospectively selected N = 34 L-dopa naïve PD subjects who had undergone standardized electroencephalography. We selected N = 18 subjects group-matched by age, sex and hand dominance with normal electroencephalography and no parkinsonism and/or cognitive decline as controls. A Welchs periodogram was applied to electroencephalographic signal epochs recorded from homologous pairs of electrodes over each hemisphere. An index of lateralization was then obtained as the absolute value of the electroencephalographic asymmetry index, computed by subtracting left from right-sided log power spectral density for each homologous site and frequency band. A standardized L-dopa acute challenge test was performed on all PD subjects to compute short-duration response magnitude. RESULTS In mid/lateral frontal regions higher index of lateralization for the beta band (p = 0.015) and lower index of lateralization for the theta band (p = 0.036) were found in PD subjects as compared to controls. Both parameters correlated with Hoehn-Yahr staging (beta: r = 0.428, p = 0.012; theta: r = -0.464, p = 0.006). In occipital region lower index of lateralization for the alpha band was found in PD correlating with L-dopa short-duration response magnitude (r = 0.456; p = 0.007). CONCLUSIONS Lateralization of frontal cortex beta electroencephalographic activity is associated with clinical disability. Occipital cortex alpha activity may relate to L-dopa responsiveness in untreated PD subjects.

A Wearable Device to Support the Pull Test for Postural Instability Assessment in Parkinson’s Disease

The pull test (PT) is a common practice to assess the postural instability of patients with Parkinson’s disease. Postural instability is a serious issue for elderly and people with neurological disease, which can cause falls. The implementation of the PT consists in observing the user response after providing a tug to the patients’ shoulders, in order to displace the center of gravity from its neutral position. The validity of the test can be compromised by a nonstandard backward tug provided to the patient. The solution proposed in this paper consists of a low-cost multisensor system allowing an instrumented estimation of the input solicitation. Moreover, the system provides supplementary information on the user postural stability, by means of a set of features extracted from the user stabilogram. A wide set of experiments have been performed to assess the system capability to provide a rough classification between stable and unstable behaviors. Results obtained demonstrate the validity of the approach proposed, with very low rates of false positive and false negative.

Side effects induced by the acute levodopa challenge in Parkinson's Disease and atypical parkinsonisms.

Introduction Acute levodopa challenge may be performed to predict levodopa chronic responsiveness. The aim of the study was to investigate frequency of side effects during the acute levodopa challenge in PD and atypical parkinsonisms. Methods We enrolled 34 de novo PD patients and 29 patients affected by atypical parkinsonisms (Multiple System Atrophy, MSA, n = 10; Progressive Supranuclear Palsy, PSP, n = 12 and Corticobasal Degeneration, CBD, n = 7) who underwent an acute levodopa challenge. Side effects occurring during test were recorded. Results Side effects were more frequent among atypical parkinsonisms as unique group when compared to PD patients (64.3% versus 23.5%; p-value 0.002) with an adjusted OR of 4.36 (95%CI 1.40–13.5). Each atypical parkinsonisms showed almost double occurrence of side effects (MSA 90%, PSP 41.7% and CBD 57%). Conclusions Side effects during acute levodopa challenge may be frequent in atypical parkinsonisms. This information could be useful in order to better prepare the patient for the test. Furthermore, it could represent a useful cue in differential diagnosis with PD.

Does the StartReact effect apply to first-trial reactive movements?

Introduction StartReact is the acceleration of reaction time by a startling acoustic stimulus (SAS). The SAS is thought to release a pre-prepared motor program. Here, we investigated whether the StartReact effect is applicable to the very first trial in a series of repeated unpractised single-joint movements. Methods Twenty healthy young subjects were instructed to perform a rapid ankle dorsiflexion movement in response to an imperative stimulus. Participants were divided in two groups of ten. Both groups performed 17 trials. In one group a SAS (116 dB) was given in the first trial, whereas the other group received a non-startling sound (70 dB) as the first imperative stimulus. In the remaining 16 trials, the SAS was given as the imperative stimulus in 25% of the trials in both groups. The same measurement was repeated one week later, but with the first-trial stimuli counterbalanced between groups. Results When a SAS was given in the very first trial, participants had significantly shorter onset latencies compared to first-trial responses to a non-startling stimulus. Succeeding trials were significantly faster compared to the first trial, both for trials with and without a SAS. However, the difference between the first and succeeding trials was significantly larger for responses to a non-startling stimulus compared to responses triggered by a SAS. SAS-induced acceleration in the first trial of the second session was similar to that in succeeding trials of session 1. Discussion The present results confirm that the StartReact phenomenon also applies to movements that have not yet been practiced in the experimental context. The excessive SAS-induced acceleration in the very first trial may be due to the absence of integration of novel context-specific information with the existing motor memory for movement execution. Our findings demonstrate that StartReact enables a rapid release of motor programs in the very first trial also without previous practice, which might provide a behavioural advantage in situations that require a rapid response to a potentially threatening environmental stimulus.

Switching L-dopa Therapy from Pulsatile to Pulse Administration Reduces Motor Complications in Parkinsonʼs Disease

Objective To evaluate the severity of wearing-off and dyskinesia in patients with complicated Parkinson disease (PD) after switching L-dopa oral therapy from a “pulsatile” administration, consisting in intermittent multiple daily small doses of the drug, to a “pulse” administration, consisting in standard oral doses given at specific interdose intervals. Methods Thirty-four PD patients with motor complications were monitored twice with standardized waking day motor status evaluations using the Unified Parkinson Disease Rating Scale-Motor Examination (UPDRS-ME) and the Abnormal Involuntary Movement Scale (AIMS) after switching L-dopa administration modality from “pulsatile” to “pulse.” To quantify predictable motor fluctuations, a Wearing Off Index was computed based on changes in treatment response magnitude. Results On the whole, after switching from “pulsatile” to “pulse” administration, there was a reduction in number of L-dopa daily doses and an increase in the amount of the dosage of the single doses, AIMS maximum score decreased without increasing motor disability. More specifically, in predominant fluctuating patients, there was a significant reduction in UPDRS-ME average score as well as in Wearing Off Index. In predominant dyskinetic patients, there was a significant reduction in average and maximum AIMS scores with no changes in average and maximum UPDRS-ME scores. Conclusions Switching L-dopa therapy from “pulsatile” to “pulse” modality may reduce the severity of wearing-off and dyskinesia in complicated PD.

Temperament Traits And Executive Functions In Parkinson's Disease.

INTRODUCTION Aim of the study was to evaluate the possible relationship between Temperament traits and executive dysfunction in patients with Parkinsons disease (PD). METHODS Patients affected by PD diagnosed according to the UK Parkinsons disease Society Brain Bank criteria were enrolled in the study. Patients with a Mini Mental State Examination <24 were excluded from the study. The Temperament and Character Inventory (TCI), a self-report questionnaire assessing the Harm Avoidance (HA), Novelty Seeking (NS) and Reward Dependence (RD) temperamental traits, has been performed. The executive functions were assessed with the Frontal Assessment Battery (FAB). RESULTS Fifty PD patients (28 men and 22 women; mean age 59.1 ± 10.1 years) were enrolled. High HA (mean score 73.3 ± 24.7) and a low NS score (24.2 ± 18.7) were recorded. Fifteen (30%) patients presented a pathological FAB score (≤13.5). Patients with a pathological FAB score presented an HA score significantly higher than patients with normal FAB score (respectively 84.9 ± 13.7 versus 69.8 ± 26.9; p = 0.045). At the univariate analysis an association between high HA score and pathological FAB score was found (OR 3.85, 95%CI 1.06-13.9; p-value 0.040). CONCLUSION Our study confirmed an association between executive disturbances and HA in PD patients, possibly related to a common impairment of the frontostriatal circuits.

Dopaminergic and non-dopaminergic gait components assessed by instrumented timed up and go test in Parkinson’s disease

The timed up and go test (TUG) is a widely used clinical test for the evaluation of balance and mobility. An instrumented version of TUG (iTUG) has been proposed to provide quantitative information on TUG performances. Here, we hypothesized that l-dopa may differently influence gait parameters recorded by a portable inertial sensor. To test this idea, we evaluated iTUG test in patients with Parkinson’s disease (PD), both in l-dopa OFF and ON state. Twenty-eight PD patients performed the iTUG. Subjects were instructed to perform the task both in practical “OFF” and “ON” state. The system differentiated the test in six phases, recording phase durations, three-axial accelerations, average and peak angular speeds during turning. In all patients, sit-to-stand vertical and medio-lateral accelerations together with turning phase duration and angular speeds improved after l-dopa administration, while sit-to-stand and stand-to-sit phases antero-posterior accelerations were less responsive. In PD, l-dopa modulates iTUG in different ways, mostly improving the turning phases and less acting on postural controls during the sit-to-stand and stand-to-sit phases. Our results suggest different involvement of dopaminergic mechanisms on gait as assessed by iTUG. This is important for those aspects which are not improved by pharmacological therapy.