Quantitative EEG in Parkinson's disease: when REM sleep behavior disorder onset really matters.

Parkinson's Disease (PD) body-first subtype is characterized by prodromal autonomic symptoms and REM sleep behavior disorder (RBD), symmetric dopaminergic degeneration, and increased risk of dementia. On the other hand, the PD brain-first subtype has fewer non-motor symptoms and a milder motor phenotype. The temporal relationship between RBD onset and motor symptoms onset may differentiate these two subtypes. We aimed to investigate electrocortical differences between brain-first and body-first PD patients. PD patients with an available routinely collected EEG were retrospectively selected. RBD was diagnosed using the RBD screening questionnaire (≥ 6). According to the onset of RBD patients were classified into PD-RBDpre (RBD onset before motor symptoms) and PD-RBDpost (RBD onset after motor symptoms). Patients without RBD were classified as PD-RBD-. Presence of Mild Cognitive Impairment (MCI) was diagnosed according to the MDS criteria. EEG Spectral analysis was performed in resting state by computing the Power Spectral Density (PSD) of site-specific signal epochs for the common frequency bands (delta, theta, alpha, beta). Thirty-eight PD-RBD-, 14 PD-RBDpre and 31 PD-RBDpost patients were recruited. Comparing both global and site-specific absolute values, we found a significant trend toward beta band reduction going from PD-RBD-, PD-RBDpost and PD-RBDpre. No significant differences were found between PD-RBDpost and PD-RBD- patients. PD-RBDpre patients may represent a different subset of patients as compared to patients without RBD, while patients with later onset have intermediate EEG spectral features. Quantitative EEG may provide new hints in PD subtyping.

Can mobile health apps with smartphones and tablets be the new frontier of cognitive rehabilitation in older individuals? A narrative review of a growing field.

INTRODUCTION: A recent interesting field of application of telemedicine/e-health involved smartphone apps. Although research on mHealth began in 2014, there are still few studies using these technologies in healthy elderly and in neurodegenerative disorders. Thus, the aim of the present review was to summarize current evidence on the usability and effectiveness of the use of mHealth in older adults and patients with neurodegenerative disorders. METHODS: This review was conducted by searching for recent peer-reviewed articles published between June 1, 2010 and March 2023 using the following databases: Pubmed, Embase, Cochrane Database, and Web of Science. After duplicate removal, abstract and title screening, 25 articles were included in the full-text assessment. RESULTS: Ten articles assessed the acceptance and usability, and 15 articles evaluated the efficacy of e-health in both older individuals and patients with neurodegenerative disorders. The majority of studies reported that mHealth training was well accepted by the users, and was able to stimulate cognitive abilities, such as processing speed, prospective and episodic memory, and executive functioning, making smartphones and tablets valuable tools to enhance cognitive performances. However, the studies are mainly case series, case-control, and in general small-scale studies and often without follow-up, and only a few RCTs have been published to date. CONCLUSIONS: Despite the great attention paid to mHealth in recent years, the evidence in the literature on their effectiveness is scarce and not comparable. Longitudinal RCTs are needed to evaluate the efficacy of mHealth cognitive rehabilitation in the elderly and in patients with neurodegenerative disorders.

Retinal Thickness in Essential Tremor and Early Parkinson Disease: Exploring Diagnostic Insights.

BACKGROUND: Essential tremor (ET) represents a heterogeneous condition which may overlap with Parkinson disease (PD) even at early stages, by sharing some subtle clinical aspects. Longstanding ET demonstrated also higher risk of developing PD, especially with a Tremor-dominant (TD-PD) phenotype. Therefore, differential diagnosis between ET and early PD could be quite challenging. Optical coherence tomography (OCT) has been recognized as a reliable tool to assess the retina as a proxy of neurodegeneration. We aimed to explore the possible role of retinal assessment in differential diagnosis between ET and early PD. METHODS: Macular layers and peripapillary retinal nerve fiber layer (RNFL) thickness among ET, early PD, and healthy controls (HCs) were assessed using OCT. RESULTS: Forty-two eyes from 23 ET, 41 eyes from 21 early PD, and 33 eyes from 17 HCs were analyzed. Macular RNFL, ganglion cell layer, inner plexiform layer, and inner nuclear layer were thinner in PD as compared with ET and even more in HCs. Differences between ET and PD were more evident when considering the TD-PD subgroup, especially for RNFL. Among ET patients, thickness of the inner macular layers showed negative linear relationship with both age at onset and disease duration. Peripapillary temporal quadrant thinning was found in ET compared with HCs. CONCLUSIONS: Macular inner retina was thinner in patients with ET and early PD compared with HCs. These findings suggest that the retinal assessment may have a utility in the differential diagnosis between ET and PD.

Gender differences in non-motor fluctuations in Parkinson's disease.

Non-motor symptoms (NMS) and Non-motor fluctuations (NMF) in Parkinson's Disease (PD) are common, involving several domains and affecting quality of life. Aim of the study is to estimate the burden of NMF in PD patients and to evaluate the possible gender effect. PD patients fulfilling the MDS-PD diagnostic criteria attending the "Parkinson's Disease and Movement Disorders Centre" of the University of Catania were evaluated using the Non-Motor Fluctuations Assessment (NoMoFA) Questionnaire. NoMoFA items were also grouped into the following domains: cognitive, mood, sleep/fatigue, dysautonomia, hallucination/perception and miscellaneous domains were identified. One-hundred and twenty-one patients with PD (67 men, 55.4%; mean age 70.2 ± 8.9 years, disease duration 8.3 ± 4.6 years) were evaluated. All PD patients reported at least one NMS, whereas 87 (71.9%) also reported NMF. "Feel sluggish or had low energy levels" (47.2%) along with "Feel excessively sleepy during the day" (40.0%) were the most common NMF reported in the whole sample. The majority of PD patients reported the presence of NMF during the OFF state (79, 65.3%). At multivariate analysis, NMF were positively associated with the female gender (adjusted OR 3.13; 95%CI 1.21-8.11 p-value 0.01). Women with PD had higher NMF scores especially in depression/anxiety, sleep/fatigue and dysautonomia domains. Our study reported the presence of a gender-related pattern in the frequency of NMS and NMF in PD patients, with female gender associated with a higher risk of developing NMF, highlighting the need for personalized treatment strategies when addressing NMF.

Brain linear measurements for differentiating normal pressure hydrocephalus from Alzheimer's disease: an exploratory study.

BACKGROUND AND PURPOSE: Easy and reliable tools for the differential diagnosis between idiopathic normal pressure hydrocephalus (iNPH) and Alzheimer's disease (AD) are needed. MATERIALS AND METHODS: In this cross-sectional study iNPH and AD patients referred to the Neurology Unit of the University of Catania from 1 January 2020 to 1 December 2022 were enrolled. The following brain linear measurements (BLMs) were calculated: Evan's index (EI), the parieto-occipital ratio (POR) and the temporal ratio (TR). For each index, sensitivity, specificity and the area under the curve (AUC) were calculated. Moreover, a cumulative index, the BLM index, was also considered. RESULTS: Fifty patients (25 iNPH and 25 AD) were enrolled. In differentiating iNPH from AD, EI had the highest AUC (0.956), POR had the highest specificity (100%) whilst TR had the highest sensitivity (92%). The BLM index differentiated iNPH and AD with a sensitivity of 96%, a specificity of 92% and an AUC of 0.963 with an optimal cut-off value of 0.303. CONCLUSION: Evan's index, POR and TR may be useful in the differential diagnosis between iNPH and AD. At an individual level, the BLM index represents a valid and reliable tool to achieve an accurate differentiation between these two conditions.

Corticobasal syndrome and Parkinson's disease at the beginning: asymmetrical patterns of MRI and Blink Reflex for early diagnosis.

Differential diagnosis between Parkinson's disease (PD) and corticobasal syndrome (CBS) could be challenging at the early stage, due to the asymmetric onset of both diseases. Despite the clinical overlap, the anatomical circuits involved in these disorders are different. We evaluated R2 Blink Reflex Recovery Cycle (R2BRRC) and cortical thickness (CTh) in drug-naïve PD and CBS patients for characterizing pathophysiological mechanisms underlying these conditions. Patients with a clinically probable diagnosis of PD and possible CBS were recruited. R2BRRC was evaluated bilaterally at interstimulus intervals (ISIs) of 100-150-200-300-400-500-750 ms. Asymmetry index (AI) of R2BRRC for each ISI was computed. Patients underwent a structural brain MRI and hemisphere CTh and AI of MRI was calculated. Fourteen drug-naïve PD patients and 10 patients with early CBS diagnosis were enrolled. R2BRRC of PD patients showed an increased brainstem excitability for less affected side (LAS) stimulation at ISIs of 100 and 150 ms (p < 0.001) compared to most affected side (MAS), whereas no differences between LAS and MAS were found in CBS. AI of R2BRRC at ISI-100 ms showed significant difference, being higher in PD. CTh analysis showed significant differences between groups in hemisphere cortical volume contralateral to MAS, and, conversely, AI of MRI was significantly higher in CBS. PD patients exhibited an asymmetric pattern of brainstem excitability, compared to CBS. Conversely, CBS patients showed an asymmetric pattern of cortical atrophy. This opposite pattern of neurophysiological and structural abnormalities involving cortical and subcortical brain structures could highlight the different pathophysiological mechanisms underlying these disorders.

Executive functioning and serum lipid fractions in Parkinson's disease-a possible sex-effect: the PACOS study.

The association between dyslipidemia and cognitive performance in Parkinson's disease (PD) patients still needs to be clarified. Aim of the study was to evaluate the presence of possible associations between serum lipids fractions and executive dysfunction also exploring the sex-specific contribute of lipids level on cognition. Patients from the PACOS cohort, who underwent a complete serum lipid profile measures (total cholesterol-TC, low-density lipoprotein cholesterol-LDL, high-density lipoprotein cholesterol-HDL and triglycerides-TG) were selected. Adult Treatment Panel III guidelines of the National Cholesterol Education Program were used to classify normal/abnormal lipid fractions. Executive functioning was assessed with the Frontal Assessment Battery (FAB). Logistic regression was performed to assess associations between lipids fractions and FAB score. Correlations between lipids fractions and FAB score were explored. Sex-stratified analysis was performed. Three hundred and forty-eight PD patients (148 women; age 66.5 ± 9.5 years; disease duration 3.9 ± 4.9 years) were enrolled. Women presented significantly higher TC, LDL and HDL than men. In the whole sample, any association between lipid profile measures and FAB score was found. Among women, a positive association between hypertriglyceridemia and FAB score under cutoff was found (OR 3.4; 95%CI 1.29-9.03; p value 0.013). A statistically significant negative correlation was found between the FAB score and triglyceride serum levels (r = - 0.226; p value 0.005). Differently, among men, a statistically significant negative association between hypercholesterolemia and FAB score under cutoff (OR 0.4; 95%CI 0.17-0.84; p value 0.018) and between high LDL levels and FAB score under cutoff (OR 0.4; 95%CI 0.18-0.90; p value 0.027) were found. Our data suggest a sex-specific different role of lipids in executive functioning.

Morphometric magnetic resonance imaging cortico-subcortical features in Parkinson's disease with mild cognitive impairment.

BACKGROUND AND PURPOSE: Parkinson's disease (PD) patients with cognitive impairment undergo progressive atrophy of several cortical and subcortical areas. The aim was to study the magnetic resonance imaging (MRI) morphometric features of PD patients with mild cognitive impairment (MCI). METHODS: Patients from the Parkinson's Disease Cognitive Impairment Study (PACOS) cohort with an available structural volumetric brain MRI and morphometric measurements of the midbrain and pons areas, middle cerebellar peduncle, superior cerebellar peduncle width and midbrain anteroposterior diameter (A-Pdiam) were included. MCI was diagnosed according to the Movement Disorder Society level II criteria. Additionally, cortical thickness analysis was performed and correlated with morphometric brainstem measurements. RESULTS: Morphometric measurements were available for 168 subjects, of whom 67 (39.9%) were diagnosed with PD-MCI. The mean age (± standard deviation) of the sample was 64.2 ± 9.8. Amongst patients, 84 (50%) were men with a disease duration of 5.2 ± 5.4 years and a Unified Parkinson's Disease Rating Scale-Motor Examination score of 32.1 ± 12.9. In the univariate and multivariate analysis, after adjusting for age, sex, years of schooling and disease duration, MCI was associated with midbrain area (odds ratio 0.98; 95% confidence interval 0.96-0.99; p = 0.048) and A-Pdiam (odds ratio 0.63; 95% confidence interval 0.46-0.86; p = 0.005). Furthermore, 121 PD patients underwent cortical thickness analysis, which showed the presence of cortical thinning in lateral orbitofrontal regions of patients with PD-MCI. No correlation was found between cortical thickness and brainstem morphometric measurements. CONCLUSIONS: A mild midbrain atrophy and the presence of frontal cortical thickness reduction might be considered a structural MRI feature of PD patients with MCI.

Pure sensitive chronic inflammatory axonal polyneuropathy following Pfizer COVID-19 vaccine.

BACKGROUND: During the worldwide mass vaccination campaign against SARS-CoV-2, multiple side effects have been observed. We described the case of a patient who developed pure sensitive chronic inflammatory axonal polyneuropathy (CIAP) in a close temporal relationship with the administration of the BNT162b2 (Pfizer®) vaccine. CASE REPORT: An 82-year-old woman developed lower limb sensory loss and "pricking" associated with marked gait imbalance after she had received her second dose of Pfizer-BioNTech COVID-19 vaccine. At the electroneurographic examination, the motor nerves conduction study was normal. Median, ulnar, and sural nerves sensory compound nerve action potential (CNAP) were bilaterally absent. Somatosensory evoked potentials (SSEPs) were not recordable. Spine MRI demonstrated roots enhancement from C3 to Th2 and diffuse enhancement of cauda equina nerve roots. She was treated with IV methylprednisolone whit benefit. A follow-up visit was made 4 months after the disease onset; a diagnosis of pure sensitive CIAP has been made. DISCUSSION: To the best of our knowledge, this is the first description of CIAP occurring in a close temporal relationship with the administration of Pfizer-BioNTech COVID-19 vaccine.

Accuracy of the clinical diagnosis of dementia with Lewy bodies (DLB) among the Italian Dementia Centers: a study by the Italian DLB study group (DLB-SINdem).

INTRODUCTION: Dementia with Lewy bodies (DLB) may represent a diagnostic challenge, since its clinical picture overlaps with other dementia. Two toolkits have been developed to aid the clinician to diagnose DLB: the Lewy Body Composite Risk Score (LBCRS) and the Assessment Toolkit for DLB (AT-DLB). We aim to evaluate the reliability of these two questionnaires, and their ability to enhance the interpretation of the international consensus diagnostic criteria. METHODS: LBCRS and AT-DLB were distributed to 135 Italian Neurological Centers for Cognitive Decline and Dementia (CDCDs), with the indication to administer them to all patients with dementia referred within the subsequent 3 months. We asked to subsequently apply consensus criteria for DLB diagnosis, to validate the diagnostic accuracy of the two toolkits. RESULTS: A total of 23 Centers joined the study; 1854 patients were enrolled. We found a prevalence of possible or probable DLB of 13% each (26% total), according to the consensus criteria. LBCRS toolkit showed good reliability, with a Cronbach alpha of 0.77, stable even after removing variables from the construct. AT-DLB toolkit Cronbach alpha was 0.52 and, after the subtraction of the "cognitive fluctuation" criterion, was only 0.31. Accuracy, sensitivity, and specificity were higher for LBCRS vs. AT-DLB. However, when simultaneously considered in the logistic models, AT-DLB showed a better performance (p < 0.001). Overall, the concordance between LBCRS positive and AT-DLB possible/probable was of 78.02% CONCLUSIONS: In a clinical setting, the LBCRS and AT-DLB questionnaires have good accuracy for DLB diagnosis.

Feasibility and usability of a non-immersive virtual reality tele-cognitive app in cognitive rehabilitation of patients affected by Parkinson's disease.

BACKGROUND: Cognitive impairment is one of the most common non-motor features of Parkinson's disease (PD). The aim of the present study was to evaluate the feasibility and acceptability/usability of a protocol using a non-immersive virtual reality tele-cognitive app, performed remotely in a sample of Italian patients with PD. METHODS: Non-demented patients with mild PD were included in the study. Patients performed the cognitive rehabilitation in a remote way, at home (three training sessions lasting 20 min/week for 6 weeks) using the NeuroNation app, downloaded for free on the patients' smartphones. The usability and feasibility of the tele-cognitive rehabilitation program were assessed with the System Usability Scale (SUS) and the Goal Attainment Scaling (GAS). RESULTS: Sixteen patients (9 men and 7 women; mean age 58.4 ± 8.3 years; mean disease duration 4.6 ± 2.1 years) were included in the study. At the end of the study, the mean SUS was 83.4 ± 11.5. The GAS score recorded at the end of the study (65.6 ± 4.2) was significantly higher than at baseline (38.5 ± 2.4; P-value <0.001). CONCLUSION: In our sample, good feasibility and usability were observed for a 6-week cognitive rehabilitation protocol based on the non-immersive virtual reality tele-cognitive app NeuroNation. Our data support the usefulness of cognitive rehabilitation performed in a remote way in PD patients.

Neuroanatomical changes in early Parkinson's disease with mild cognitive impairment: a VBM study; the Parkinson's Disease Cognitive Impairment Study (PaCoS).

INTRODUCTION: Mild cognitive impairment (MCI) is common in Parkinson's disease (PD), but the underlying pathological mechanism has not been fully understood. Voxel-based morphometry could be used to evaluate regional atrophy and its relationship with cognitive performances in early PD-MCI. PATIENTS AND METHODS: One hundred and six patients with PD were recruited from a larger cohort of patients, the Parkinson's Disease Cognitive Impairment Study (PaCoS). Subject underwent a T1-3D MRI and a complete clinical and neuropsychological evaluation. Patients were divided into PD with normal cognition (PD-NC) and PD-MCI according to the MDS level II criteria-modified for PD-MCI. A subgroup of early patients with short disease duration (≤ 2 years) was also identified. VBM analysis between PD-NC and PD-MCI and between early PD-NC and PD-MCI was performed using two-sample t tests with whole-brain statistical threshold of p < 0.001 uncorrected in the entire PD group and p < 0.05 FWE inside ROIs, in the early PD. RESULTS: Forty patients were diagnosed with MCI and 66 were PD-NC. PD-MCI patients showed significant gray matter (GM) reduction in several brain regions, including frontal gyrus, precuneus, angular gyrus, temporal lobe, and cerebellum. Early PD-MCI showed reduction in GM density in superior frontal gyrus and cerebellum. Moreover, correlation analysis between neuropsychological performances and GM volume of early PD-MCI patients showed associations between performances of Raven and superior frontal gyrus volume, Stroop time and inferior frontal gyrus volume, accuracy of Barrage and volume of precuneus. CONCLUSION: The detection of frontal and cerebellar atrophy, even at an early stage, could be used as an early marker of PD-related cognitive impairment.

Specific Signatures of Serum miRNAs as Potential Biomarkers to Discriminate Clinically Similar Neurodegenerative and Vascular-Related Diseases.

Neurodegenerative diseases (NDs) are age-dependent; among them, Alzheimer's disease (AD) and Parkinson's disease (PD) are the most frequent. Similarly, cerebrovascular damage can induce the development of vascular-related disorders that share common features with AD and PD, respectively, named vascular dementia (VD) and vascular parkinsonism (VP). To date, ND diagnosis is mainly clinical; therefore, since these disorders show similar symptoms, their correct discrimination may be difficult. We detected 23 ND-associated microRNAs (miRNAs) by literature mining and investigated their serum expression in a cohort of 139 patients including AD, PD, VD, and VP patients and healthy controls. TaqMan RT-PCR data showed that miR-23a upregulation was associated with an ongoing neurodegenerative process, similar to miR-22* and miR-29a, while let-7d, miR-15b, miR-24, miR-142-3p, miR-181c, and miR-222 showed an altered expression in Parkinson-like phenotypes, as well as miR-34b, miR-125b, and miR-130b in Alzheimer-like disorders. By computing logistic regression models and ROC curves, we identified signatures of neuro-miRNAs specific for each disease, showing good diagnostic performance. Interestingly, we found that miR-23a, miR-29a, miR-34b, and miR-125b exhibited a different distribution between exosomes and vesicle-free serum, suggesting a heterogeneity of secretion for these miRNAs. Our results suggest that miRNA signatures could discriminate in a non-invasive manner neurodegenerative disorders, thus improving clinical diagnoses.

Cognitive-Behavioural Correlates of Dysbiosis: A Review.

Evidence suggests an association between an altered gut microbiota (dysbiosis), cognitive performance and behaviour. This paper provides an overview of the current literature regarding the cognitive-behavioural correlates of dysbiosis, with special attention on the clinical and biochemical mechanisms underlying the association between dysbiosis, cognition (mild cognitive impairment and dementia) and behaviour (depression, schizophrenia, addiction). After providing an overview of the evidence, the review discusses the molecular aspects that could account for the cognitive-behavioural correlates of dysbiosis. Shedding light on this topic could provide insights regarding the pathogenesis of these burdening neuropsychiatric disorders and even suggest future therapeutic strategies.

Complexity of electrocortical activity as potential biomarker in untreated Parkinson's disease.

In Parkinson's disease (PD), the identification of instrumental biomarkers is crucial to evaluate disease susceptibility and motor stage. We evaluated self-similarity of electrocortical activity as expression of brain signal complexity in untreated PD, to investigate its possible role as a neurophysiological biomarker. We analyzed the data of 34 untreated PD subjects and 18 group-matched controls who underwent standardized electroencephalography. A Welch's periodogram was applied to site-specific electroencephalographic signal epochs. To investigate self-similarity of electrocortical activity, the power law exponent ß was computed for each selected coordinate. In both PD subjects and controls, ß values at each coordinate increased with an antero-posterior gradient, changing from values around one in fronto-temporal sites to values around two among parieto-occipital sites. PD subjects presented overall lower ß values among different sites compared to controls, with significant differences for the left fronto-temporal sites. Our findings suggest an increased level of fronto-temporal neuronal organization in untreated PD. We hypothesize a possible role of ß as a neurophysiological biomarker for early untreated PD.

Accuracy of MDS-UPDRS section IV for detecting motor fluctuations in Parkinson's disease.

BACKGROUND: In a precedent paper, we validated part IV of the Unified Parkinson's Disease Rating Scale (UPDRS) for detecting motor fluctuations in Parkinson's Disease (PD) patients using a 12-h Waking-Day Motor Assessment (WDMA) as gold standard, showing a high sensitivity (> 80%) and a lower specificity (< 45%). The aim of this study was to validate the Movement Disorder Society-UPDRS (MDS-UPDRS) part IV, especially items 4.3 and 4.5, using the same methodology. METHODS: PD patients attending the Movement Disorders Clinic at the University Hospital in Catania were consecutively enrolled in the study. A diurnal WDMA was performed to detect motor fluctuations. At each time interval, the motor impairment was evaluated using the motor section of the MDS-UPDRS. Presence or absence of motor fluctuations and the type of motor fluctuation were assessed by four blinded expert raters in movement disorders, by evaluating the graphical representations of the WDMA. We evaluated sensitivity and specificity together with 95% Confidence Interval (CI) of items 4.3 and 4.5, using WDMA as gold standard. RESULTS: We estimated for item 4.3 of the MDS-UPDRS a sensitivity of 74.3% (95% CI 56.7-87.5) and a specificity of 70.6% (95% CI 44-89.7), while for item 4.5, a sensitivity of 67.9% (95% CI 47.6-84.1) and a specificity of 66.7% (95% CI 44.7-84.4). CONCLUSIONS: The present showed a higher specificity level for MDS-UPDRS with respect to the UPDRS, while a slightly lower sensitivity mainly for predictable OFF.

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.