Tremor Severity Research Articles

Bilateral globus pallidus interna deep brain stimulation in Parkinson's disease: Therapeutic effects and motor outcomes prediction in a short-term follow up.

We aimed to compare the motor effect of bilateral globus pallidus interna (GPi) deep brain stimulation (DBS) on motor subtypes of Parkinson's disease (PD) patients and identify preoperative predictive factors of short-term motor outcome. We retrospectively investigated bilateral GPi DBS clinical outcomes in 55 PD patients in 1 year follow up. Motor outcome was measured by the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III before and 1 year after surgery. Clinical outcomes were compared among different motor subtypes. Preoperative predictors of motor outcome were assessed by performing univariate and multivariate linear regression and logistic regression analyses. At 1 year following implantation, GPi DBS significantly improved the off-medication MDS-UPDRS III scores in all motor subtype cohorts, with prominent improvement in tremor. No significant difference of postoperative motor symptoms changes was found except greater tremor improvement achieved in both the tremor-dominant (TD) and indeterminate (IND) patients compared to the postural instability and gait difficulty (PIGD) patients. High percentage of PIGD patients were weak responders to DBS. Better levodopa responsiveness and more severe tremor predicted greater overall improvement of motor function in the entire cohort. Similarly, both levodopa responsiveness and tremor improvement were confirmed as predictors for motor improvement in PIGD patients. Bilateral GPi DBS could effectively improve motor outcomes in PD patients regardless of motor subtypes. Both TD and IND patients obtained larger tremor improvement. The intensity of levodopa responsiveness and the severity of tremor could serve as predictors of motor improvement 1 year after GPi DBS.

Brain microstructural changes in essential tremor patients and correlations with clinical characteristics: a diffusion kurtosis imaging study.

Essential tremor (ET) is the second most common movement disorder; however, the pathophysiological mechanism of ET is unclear. We aimed to investigate the microstructural degeneration of gray matter (GM) and white matter (WM) and their correlations with cognition and tremor in patients with ET. The participants were 63 patients with ET and 63 matched healthy controls (HCs) who underwent 3D-T1 weighted and diffusion kurtosis images (DKI). Microstructural degeneration was measured using high-level diffusion parameters derived from DKI. A voxel-wise analysis of the means of the GM-based spatial statistics and tract-based spatial statistics were conducted to assess differences in diffusion parameters between the ET and HC groups. The volume differences between the two groups were also assessed, and tremor severity and multi-domain cognitive performance were evaluated. Finally, the relationship between microstructural degeneration and clinical characteristics were assessed. The ET group had significantly lower mean kurtosis of the temporal, parietal, and occipital lobes and the cerebellum and lower radial kurtosis in several tracts. These microstructural changes in GM and WM were correlated with tremor and cognitive scores. However, no significant difference in volume was found between the groups. Our findings suggest that ET entails extensive GM and WM microstructural alterations, which support the neurodegenerative hypothesis of ET. Our study contributes to a better understanding of the mechanisms underlying tremor and cognitive impairment in ET.

Tremor, Gait, and Balance Disorders in Essential Tremor and the Efficacy of Atenolol

ABSTRACT Background: To assess gait and balance in patients with essential tremor (ET), which is the most common tremor disorder characterized by bilateral action tremor of the hands with possible involvement of further tremor locations and to test the efficacy of atenolol on tremor and gait and balance. Methods: In this prospective study, gait and balance were evaluated by static posturography in addition to International Cooperative Ataxia Rating Scale (ICARS) in 22 ET patients without any additional neurologic signs on examination. Tremor severity was assessed by The Essential Tremor Rating Assessment Scale (TETRAS). The efficacy of atenolol 100 mg/day both on tremor and gait and balance was investigated. Posturographic recordings were performed in gender, age-, and height-matched healthy volunteers who constituted the control group. Results: The mean center of gravity sway velocity of the ET patients recorded on firm and foam surfaces with eyes open and closed was not significantly different from the healthy controls but sway velocity on tandem stance was significantly increased (P = 0.032). Gait speed (P = 0.015) was decreased and step width was increased (P = 0.001). An improvement in TETRAS scores was recorded with atenolol treatment (P = 0.046). An improvement not reaching statistical significance was present in ICARS scores (P = 0.059). However, posturographic parameters did not change significantly (P > 0.05). Conclusion: Increased sway velocity on tandem stance, decreased gait speed and increased step width are consistent with midline cerebellar dysfunction in ET patients with no obvious gait and balance deficits on clinical examination. Atenolol seems to be effective on tremor but does not cause a significant improvement in gait and balance deficits.

Deep Brain Stimulation for Holmes Tremors and Literature Review.

Deep Brain Stimulation for Holmes Tremors and Literature Review.

Retracted: Task-Oriented Intelligent Solution to Measure Parkinson's Disease Tremor Severity.

[This retracts the article DOI: 10.1155/2021/9624386.].

COMPARATIVE EVALUATION OF THE NUTRITIONAL STATE AND HABITS IN PARKINSON PATIENTS WITH DEEP BRAIN STIMULATION TREATMENT AND MEDICAL TREATMENT

Amaç: Bu çalışmada, derin beyin stimülasyonu (DBS) ameliyatı olan Parkinson hastaları (PH) ile ilaç tedavisi alan Parkinson hastalarının beslenme durumu ve alışkanlıklarının değerlendirilmesi amaçlandı. 
 Materyal Metot: Çalışmanın materyalini Ondokuz Mayıs Üniversitesi Hastanesi Nöromodülasyon Merkezine başvuran DBS cerrahisi uygulanmış 24, DBS cerrahisi uygulanmamış 24 Parkinson hastası ile 24 sağlıklı kontrol grubu oluşturdu. Çalışmaya katılan hastalar altı ay boyunca takip edildiler. Araştırmaya katılan tüm bireylere ait genel bilgiler, antropometrik ölçümler, besin tüketim durumları ve beslenme alışkanlıkları yöntemine uygun olarak saptandı. Levadopa eşdeğeri günlük dozları hastaların tremorunun şiddetine göre belirlendi. DBS ameliyatının ilk kısmı lokal anestezi altında, ikinci kısmı ise genel anestezi altında yapıldı.
 Bulgular: DBS uygulanmış ve DBS uygulanmamış Parkinsonlu erkek ve kadın hastaların antropometrik ölçümlerinde kalori, besin gruplarında şeker ve tatlı grubu önemli bulundu (p

The mechanism of antidepressant action of a new 3-substituted thiethane-1,1-dioxide derivative in tests of neuropharmacological interaction

Introduction: The present study is aimed at investigation of the mechanism of action of a new 3-substituted thi­etane-1,1-dioxide derivative (N-199/1) exhibiting antidepressant properties, in several tests of neuropharmaco­logical interaction.
 Materials and methods: To study the mechanism of action of N-199/1, its effect on 5-hydroxytryptophan (5-HTP)-induced head-twitch response (50 mg/kg and 300 mg/kg), haloperidol-induced catalepsy (1 mg/kg), arecoline-induced tremor (6 mg/kg), picrotoxin-induced seizures (6 mg/kg) and hypothermia, induced by apomorphine (10 mg/kg) or L-3,4-dihydroxyphenylalanine (L-DOPA, 140 mg/kg), was assessed when administered singly to white outbred male mice at a dose of 2 mg/kg.
 Results and discussion: N-199/1 reduced the number of head twitches, induced by 5-HTP (300 mg/kg), by 83% 45 min after 5-HTP injection; decreased the duration of haloperidol catalepsy by 1–32 s 15–45 min after haloperidol injection; attenuated L-DOPA-induced hypothermia by 0.7 °С and apomorphine-induced hypothermia by 0.6 °С at the timepoint of 30 min; reduced the duration and severity of arecoline tremor and did not affect the convulsive effect of picrotoxin.
 Conclusion: N-199/1 acts on serotonergic, noradrenergic, dopaminergic and cholinergic neurotransmission and does not affect neuronal reuptake of monoamines or monoamine oxidase. The mechanism of action of N-199/1 is probably due to stimulation of serotonergic 5HT1A-receptors and/or blockade of 5HT2A/2C-receptors and/or α2-adrenergic receptors; dopaminergic and cholinergic receptors may also be involved.
 Graphical abstract:

Evaluation of Cerebral Volume Changes in Patients with Tremor Treated by MRgFUS Thalamotomy.

The purpose of the study is to quantify volumetric variations of cortical and subcortical brain structures after Vim ablation using MRgFUS, and correlate them with the patients' clinical features and treatment outcomes. For this pilot retrospective study we enrolled 31 patients with a mean age of 70.86 years who were eligible for unilateral Vim thalamotomy. Clinical evaluation included tremor severity assessment using the FTM scale and cognitive assessment using the MoCA score. MRI data were acquired with a 3T scanner, using a dedicated 32-channel coil and acquiring a volumetric sequence of T1 3D IR FSPGR (BRAVO), before treatment and one year after MRgFUS thalamotomy. Image processing and volume data extraction were conducted with dedicated software. A volumetric analysis showed a significant reduction (p < 0.05) of the left thalamus 1 year after the treatment in patients with ET. Other significant results were found on the same side in the other nuclei of the basal ganglia and in the cerebellar cortex. In confronting the two groups (ET, PD), no significant differences were found in terms of age, FTM, MoCA scores, or brain volumes. Similarly, no significant correlations were found between the FTM and MoCA scores and the brain volumes before the treatment.

Stepwise Dual-Target Magnetic Resonance–Guided Focused Ultrasound in Tremor-Dominant Parkinson Disease: A Feasibility Study

Magnetic resonance-guided focused ultrasound (MRgFUS) has been applied successfully in treating refractory tremors in Parkinson disease (PD). It generates a precise thermal ablation in a specific nucleus or tract, such as ventral intermediate nucleus (VIM) or pallidothalamic tract (PTT). Despite a single lesion improving parts of the PD symptoms, the feasibility and efficacy of a stepwise dual-lesion in VIM and PTT are yet to be explored. Three patients with tremor-dominant PD (aged 60.7 ± 6.0 years) received dual-target MRgFUS treatment with a series of primary and secondary outcome measures. The VIM and PTT were navigated based on individual magnetic resonance imaging planning of the brain. The primary outcome measures were the off-status Clinical Rating Scale for Tremor and Unified Parkinson's Disease Rating Scale part III (UPDRS-III). The secondary outcome measures included UPDRS I, II, IV, Hohen and Yahr score, Neuropsychiatry Inventory, Quality of life in PD Rating Scale, Non-Motor Symptoms Scale, and Clinical Global Impression. The baseline data were compared with those acquired 1 day and 1 month following the treatment. The severity of tremor and motor deficits represented by Clinical Rating Scale for Tremor-part B and UPDRS III were significantly improved (P < 0.05 by nonparametric Mann-Whitney U tests) after dual-target ablations. The nonmotor symptoms investigated by UPDRS II and Non-Motor Symptoms Scale also showed significant improvement at the 1-day and 1-month follow-up. There was no adverse effect except temporary procedure-related headache and dizziness during the treatment. Stepwise dual-lesion targeting VIM and PTT is a safe and effective MRgFUS therapeutic strategy for patients with PD.

Identification and Characterization of Short-Term Motor Patterns in Rest Tremor of Individuals with Parkinson's Disease.

(1) Background: The dynamics of hand tremors involve nonrandom and short-term motor patterns (STMPs). This study aimed to (i) identify STMPs in Parkinson's disease (PD) and physiological resting tremor and (ii) characterize STMPs by amplitude, persistence, and regularity. (2) Methods: This study included healthy (N = 12, 60.1 ± 5.9 years old) and PD (N = 14, 65 ± 11.54 years old) participants. The signals were collected using a triaxial gyroscope on the dorsal side of the hand during a resting condition. Data were preprocessed and seven features were extracted from each 1 s window with 50% overlap. The STMPs were identified using the clustering technique k-means applied to the data in the two-dimensional space given by t-Distributed Stochastic Neighbor Embedding (t-SNE). The frequency, transition probability, and duration of the STMPs for each group were assessed. All STMP features were averaged across groups. (3) Results: Three STMPs were identified in tremor signals (p &lt; 0.05). STMP 1 was prevalent in the healthy control (HC) subjects, STMP 2 in both groups, and STMP3 in PD. Only the coefficient of variation and complexity differed significantly between groups. (4) Conclusion: These results can help professionals characterize and evaluate tremor severity and treatment efficacy.

Exploring the heterogeneous morphometric data in essential tremor with probabilistic modelling

Essential tremor (ET) is a prevalent movement disorder characterized by marked clinical heterogeneity. Here, we explored the morphometric underpinnings of this cross-subject variability on a cohort of 34 patients with right-dominant drug-resistant ET and 29 matched healthy controls (HCs). For each brain region, group-wise morphometric data was modelled by a multivariate Gaussian to account for morphometric features’ (co)variance.No group differences were found in terms of mean values, highlighting the limits of more basic group comparison approaches. Variance in surface area was higher in ET in the left lingual and caudal anterior cingulate cortices, while variance in mean curvature was lower in the right superior temporal cortex and pars triangularis, left supramarginal gyrus and bilateral paracentral gyrus. Heterogeneity further extended to the right putamen, for which a mixture of two Gaussians fitted the ET data better than a single one.Partial Least Squares analysis revealed the rich clinical relevance of the ET population’s heterogeneity: first, increased head tremor and longer symptoms’ duration were accompanied by broadly lower cortical gyrification. Second, more severe upper limb tremor and impairments in daily life activities characterized the patients whose morphometric profiles were more atypical compared to the average ET population, irrespective of the exact nature of the alterations.Our results provide candidate morphometric substrates for two different types of clinical variability in ET. They also demonstrate the importance of relying on analytical approaches that can efficiently handle multivariate data and enable to test more sophisticated hypotheses regarding its organization.

Unified Parkinson’s Disease Rating Scale (UPDRS) motor score subscale trajectories in Dementia with Lewy Bodies and Parkinson Disease Dementia in a community autopsy cohort

AbstractBackgroundWe previously reported that in our autopsy‐confirmed cohort of Dementia with Lewy Bodies (DLB), Parkinson’s Disease Dementia (PDD) and Alzheimer’s Disease (AD), DLB with parkinsonism (DLB+Park) predicted faster progression of UPDRS‐III scores compared to PDD, DLB without parkinsonism (DLB‐Park), and AD. This study examined annualized rate of change of UPDRS‐III subscales in our cohort.MethodsData included were from participants in Arizona Study of Aging and Neurodegenerative Diseases (AZSAND) with clinicopathologic diagnosis of DLB (n = 48), PDD (n = 98) or pure AD (n = 48), and longitudinal movement exams. Mixed effects model (accounting for age, education, and sex) was used to determine predicted mean UPDRS‐III and subscale scores (0‐4) for all groups. Individual UPDRS‐III subscale scores were derived for: Body Bradykinesia, Limb Bradykinesia, Gait, Postural Instability, Limb Rest Tremor, Neck Rigidity and Limb Rigidity. Where applicable, scores for multiple limbs involved were averaged.ResultsLongitudinal data was analyzed for over 1430‐participant years. Parkinsonism was present in 65.6% of DLB participants. PDD participants were more likely to be treated with dopaminergic agents (87.8%) compared to (p&lt;0.001) DLB+Park (57.6%), DLB‐park (0%) and AD (2.1%). Frequency (29.4% vs. 29.0%) and severity (mean±SE = 0.4±0.07 and 0.4±0.12) of Limb Rest Tremor was similar for PDD and DLB+park. Limb Bradykinesia frequency and severity were PDD: 100%, 2.4±0.11, DLB+Park: 96.8%, 2.1±0.18, DLB‐Park: 20%, 0.4±0.23, and AD: 62%, 1.1±0.16. Frequency of gait abnormality was 98.5% in PDD, 90.3% in DLB+park, 60% in DLB‐Park and 57.8% in AD. Rigidity was most frequent in the PDD group (88.2%), followed by DLB+Park (71%), AD (19.6%), and none DLB‐park (0%). Over 8 years trajectories for limb bradykinesia and gait were greater for DLB+park than PDD (Figure 1, Cohen’s d range 0.89‐2.18 and 0.63‐1.99 over 8 years, p&lt;0.001).ConclusionOur results suggest that DLB+Park group have faster motor progression predominantly related to gait abnormalities and limb bradykinesia. Future analyses will explore more convergent data, integrated effects of various measures and their differential contributions in this cohort.

Propranolol Modulates Cerebellar Circuit Activity and Reduces Tremor.

Tremor is the most common movement disorder. Several drugs reduce tremor severity, but no cures are available. Propranolol, a β-adrenergic receptor blocker, is the leading treatment for tremor. However, the in vivo circuit mechanisms by which propranolol decreases tremor remain unclear. Here, we test whether propranolol modulates activity in the cerebellum, a key node in the tremor network. We investigated the effects of propranolol in healthy control mice and Car8wdl/wdl mice, which exhibit pathophysiological tremor and ataxia due to cerebellar dysfunction. Propranolol reduced physiological tremor in control mice and reduced pathophysiological tremor in Car8wdl/wdl mice to control levels. Open field and footprinting assays showed that propranolol did not correct ataxia in Car8wdl/wdl mice. In vivo recordings in awake mice revealed that propranolol modulates the spiking activity of control and Car8wdl/wdl Purkinje cells. Recordings in cerebellar nuclei neurons, the targets of Purkinje cells, also revealed altered activity in propranolol-treated control and Car8wdl/wdl mice. Next, we tested whether propranolol reduces tremor through β1 and β2 adrenergic receptors. Propranolol did not change tremor amplitude or cerebellar nuclei activity in β1 and β2 null mice or Car8wdl/wdl mice lacking β1 and β2 receptor function. These data show that propranolol can modulate cerebellar circuit activity through β-adrenergic receptors and may contribute to tremor therapeutics.

Spinocerebellar ataxia in the Bouvier des Ardennes breed is caused by a KCNJ10 missense variant.

In Belgian Malinois, a KCNJ10 variant causes progressive spinocerebellar degeneration. Describe the clinical, diagnostic, pathological and genetic features of spinocerebellar degeneration in the Bouvier des Ardennes breed. Five affected Bouvier des Ardennes puppies with spinocerebellar ataxia (SCA), 8 healthy related dogs, and 63 healthy unrelated Bouvier des Ardennes. Sequential case study. Clinical signs started at 6 weeks of age in 1 puppy with severe signs of cerebellar disease, and at 7 to 10 weeks of age in the 4 remaining puppies with milder signs of spinocerebellar disease. The first puppy displayed severe intention tremors and rapidly progressive generalized hypermetric ataxia, whereas the 4 others developed a milder progressive SCA. Euthanasia after progression to nonambulatory status was performed by 8 weeks of age in the first puppy, and before 11 months of age in the 4 remaining puppies. Histopathology revealed cerebellar spongy degeneration and a focal symmetrical demyelinating myelopathy. All cases were homozygous for KCNJ10 XM_545752.6:c.986T>C(p.(Leu329Pro)), which is pathogenic for SCA with (or without) myokymia, seizures or both (SAMS) and spongy degeneration and cerebellar ataxia (SDCA) 1 in Belgian Malinois dogs. All sampled parents were heterozygous and none of the healthy dogs were homozygous for this recessive variant. This variant has an allele frequency of 15% in the 63 healthy dogs studied. Inherited spinocerebellar degeneration also affects the Bouvier des Ardennes breed and is caused by a KCNJ10 variant. It can present with a spectrum of severity grades, ranging from severe cerebellar to milder spinocerebellar signs.

Combined Short-Pulse and Directional Deep Brain Stimulation of the Thalamic Ventral Intermediate Area for Essential Tremor

ObjectiveNovel deep brain stimulation (DBS) systems allow directional and short-pulse stimulation to potentially improve symptoms and reduce side effects. The aim of this study was to investigate the effect of short-pulse and directional stimulation, in addition to a combination of both, in the ventral intermediate thalamus (VIM)/posterior subthalamic area (PSA) on tremor and stimulation-induced side effects in patients with essential tremor. Materials and MethodsWe recruited 11 patients with essential tremor and VIM/PSA-DBS. Tremor severity (Fahn-Tolosa-Marin), ataxia (International Cooperative Ataxia Rating Scale), and paresthesia (visual analog scale) were assessed with conventional omnidirectional and directional stimulation with pulse width of 60 μs and 30 μs. ResultsAll stimulation conditions reduced tremor. The best directional stimulation with 60 μs reduced more tremor than did most other stimulation settings. The best directional stimulation, regardless of pulse width, effectively reduced stimulation-induced ataxia compared with the conventional stimulation (ring 60 μs) or worst directional stimulation with 60 μs. All new stimulation modes reduced occurrence of paresthesia, but only the best directional stimulation with 30 μs attenuated paresthesia compared with the conventional stimulation (ring 60 μs) or worst directional stimulation with 60 μs. The best directional stimulation with 30 μs reduced tremor, ataxia, and paresthesia compared with conventional stimulation in most patients. Correlation analyses indicated that more anterior stimulation sites are associated with stronger ataxia reduction with directional 30 μs than with conventional 60 μs stimulation. ConclusionDirectional and short-pulse stimulation, and a combination of both, revealed beneficial effects on stimulation-induced adverse effects.

Identification of essential tremor based on resting-state functional connectivity.

Currently, machine-learning algorithms have been considered the most promising approach to reach a clinical diagnosis at the individual level. This study aimed to investigate whether the whole-brain resting-state functional connectivity (RSFC) metrics combined with machine-learning algorithms could be used to identify essential tremor (ET) patients from healthy controls (HCs) and further revealed ET-related brain network pathogenesis to establish the potential diagnostic biomarkers. The RSFC metrics obtained from 127 ET patients and 120 HCs were used as input features, then the Mann-Whitney U test and the least absolute shrinkage and selection operator (LASSO) methods were applied to reduce feature dimensionality. Four machine-learning algorithms were adopted to identify ET from HCs. The accuracy, sensitivity, specificity and the area under the curve (AUC) were used to evaluate the classification performances. The support vector machine, gradient boosting decision tree, random forest and Gaussian naïve Bayes algorithms could achieve good classification performances with accuracy at 82.8%, 79.4%, 78.9% and 72.4%, respectively. The most discriminative features were primarily located in the cerebello-thalamo-motor and non-motor circuits. Correlation analysis showed that two RSFC features were positively correlated with tremor frequency and four RSFC features were negatively correlated with tremor severity. The present study demonstrated that combining the RSFC matrices with multiple machine-learning algorithms could not only achieve high classification accuracy for discriminating ET patients from HCs but also help us to reveal the potential brain network pathogenesis in ET.

Parkinson's disease resting tremor severity classification using machine learning with resampling techniques.

In resting tremor, the body part is in complete repose and often dampens or subsides entirely with action. The most frequent cause of resting tremors is known as idiopathic Parkinson's disease (PD). For examination, neurologists of patients with PD include tests such as finger-to-nose tests, walking back and forth in the corridor, and the pull test. This evaluation is focused on Unified Parkinson's disease rating scale (UPDRS), which is subjective as well as based on some daily life motor activities for a limited time frame. In this study, severity analysis is performed on an imbalanced dataset of patients with PD. This is the reason why the classification of various data containing imbalanced class distribution has endured a notable drawback of the performance achievable by various standard classification learning algorithms. In this work, we used resampling techniques including under-sampling, over-sampling, and a hybrid combination. Resampling techniques are incorporated with renowned classifiers, such as XGBoost, decision tree, and K-nearest neighbors. From the results, it is concluded that the Over-sampling method performed much better than under-sampling and hybrid sampling techniques. Among the over-sampling techniques, random sampling has obtained 99% accuracy using XGBoost classifier and 98% accuracy using the decision tree. Besides, it is observed that different resampling methods performed differently with various classifiers.

Tracking motion kinematics and tremor with intrinsic oscillatory property of instrumental mechanics.

Tracking kinematic details of motor behaviors is a foundation to study the neuronal mechanism and biology of motor control. However, most of the physiological motor behaviors and movement disorders, such as gait, balance, tremor, dystonia, and myoclonus, are highly dependent on the overall momentum of the whole-body movements. Therefore, tracking the targeted movement and overall momentum simultaneously is critical for motor control research, but it remains an unmet need. Here, we introduce the intrinsic oscillatory property (IOP), a fundamental mechanical principle of physics, as a method for motion tracking in a force plate. The overall kinetic energy of animal motions can be transformed into the oscillatory amplitudes at the designed IOP frequency of the force plate, while the target movement has its own frequency features and can be tracked simultaneously. Using action tremor as an example, we reported that force plate-based IOP approach has superior performance and reliability in detecting both tremor severity and tremor frequency, showing a lower level of coefficient of variation (CV) compared with video- and accelerometer-based motion tracking methods and their combination. Under the locomotor suppression effect of medications, therapeutic effects on tremor severity can still be quantified by dynamically adjusting the overall locomotor activity detected by IOP. We further validated IOP method in optogenetic-induced movements and natural movements, confirming that IOP can represent the intensity of general rhythmic and nonrhythmic movements, thus it can be generalized as a common approach to study kinematics.

The effect of regional white matter hyperintensities on essential tremor subtypes and severity.

To investigate the effect of regional white matter hyperintensities (WMHs) on Essential tremor (ET) subtypes and to explore the association between WMHs load and the severity of motor and non-motor symptoms in patients with ET. A cohort of 176 patients with ET (including 86 patients with pure ET and 90 patients with ET plus) and 91 normal controls (NC) was consecutively recruited. Demographic, clinical, and imaging characteristics were compared between individuals with pure ET, ET plus, and NC. The cross-sectional association among regional WMHs and the severity of tremor and non-motor symptoms were assessed within each group. Compared with the pure ET subgroup, the ET plus subgroup demonstrated higher TETRAS scores, NMSS scores, and lower MMSE scores (all P < 0.05). Periventricular and lobar WMHs' loads of pure ET subgroup intermediated between NC subjects and ET plus subgroup. WMHs in the frontal horn independently increased the odds of ET (OR = 1.784, P < 0.001). The age (P = 0.021), WMHs in the frontal lobe (P = 0.014), and WMHs in the occipital lobe (P = 0.020) showed a significant impact on TETRAS part II scores in the ET plus subgroup. However, only the disease duration was positively associated with TETRAS part II scores in patients with pure ET (P = 0.028). In terms of non-motor symptoms, NMSS scores of total patients with ET were associated with disease duration (P = 0.029), TETRAS part I scores (P = 0.017), and WMH scores in the frontal lobe (P = 0.033). MMSE scores were associated with age (P = 0.027), body mass index (P = 0.006), education level (P < 0.001), and WMHs in the body of the lateral ventricle (P = 0.005). Our results indicated that the WMHs in the frontal horn could lead to an increased risk of developing ET. WMHs may be used to differentiate pure ET and ET plus. Furthermore, WMHs in the frontal and occipital lobes are strong predictors of worse tremor severity in the ET plus subgroup. Regional WMHs are associated with cognitive impairment in patients with ET.

Motor imagery vividness and symptom severity in Parkinson's disease.

Motor imagery (MI), the mental simulation of movement in the absence of overt motor output, has demonstrated potential as a technique to support rehabilitation of movement in neurological conditions such as Parkinson's disease (PD). Existing evidence suggests that MI is largely preserved in PD, but previous studies have typically examined global measures of MI and have not considered the potential impact of individual differences in symptom presentation on MI. The present study investigated the influence of severity of overall motor symptoms, bradykinesia and tremor on MI vividness scores in 44 individuals with mild to moderate idiopathic PD. Linear mixed effects modelling revealed that imagery modality and the severity of left side bradykinesia significantly influenced MI vividness ratings. Consistent with previous findings, participants rated visual motor imagery (VMI) to be more vivid than kinesthetic motor imagery (KMI). Greater severity of left side bradykinesia (but not right side bradykinesia) predicted increased vividness of KMI, while tremor severity and overall motor symptom severity did not predict vividness of MI. The specificity of the effect of bradykinesia to the left side may reflect greater premorbid vividness for the dominant (right) side or increased attention to more effortful movements on the left side of the body resulting in more vivid motor imagery.