Disturbances Of Motor Function Research Articles

Trehalose consumption ameliorates pathogenesis in an inducible mouse model of the Fragile X-associated tremor/ataxia syndrome

ABSTRACT Trehalose is a naturally occurring sugar found in various food and pharmaceutical preparations with the ability to enhance cellular proteostasis and reduce the formation of toxic intracellular protein aggregates, making it a promising therapeutic candidate for various neurodegenerative disorders. Objectives Here, we explored the effectiveness of nutritional trehalose supplementation in ameliorating symptoms in a mouse model of Fragile X-associated tremor/ataxia syndrome (FXTAS), an incurable late onset manifestation of moderately expanded trinucleotide CGG repeat expansion mutations in the 5’ untranslated region of the fragile X messenger ribonucleoprotein 1 gene (FMR1). Methods An inducible mouse model of FXTAS expressing 90 CGG repeats in the brain had been previously developed, which faithfully captures hallmarks of the disorder, the formation of intracellular inclusions, and the disturbance of motor function. Taking advantage of the inducible nature of the model, we investigated the therapeutic potential of orally administered trehalose under two regimens, modelling disease prevention and disease treatment. Results and Discussion Trehalose's effectiveness in combating protein aggregation is frequently attributed to its ability to induce autophagy. Accordingly, trehalose supplementation under the prevention regimen ameliorated the formation of intranuclear inclusions and improved the motor deficiencies resulting from the induced expression of 90 CGG repeats, but it failed to reverse the existing nuclear pathology as a treatment strategy. Given the favorable safety profile of trehalose, it is promising to further explore the potential of this agent for early stage FXTAS.

Longitudinal investigation of changes in resting-state co-activation patterns and their predictive ability in the zQ175 DN mouse model of Huntington’s disease

Huntington’s disease (HD) is a neurodegenerative disorder caused by expanded (≥ 40) glutamine-encoding CAG repeats in the huntingtin gene, which leads to dysfunction and death of predominantly striatal and cortical neurons. While the genetic profile and clinical signs and symptoms of the disease are better known, changes in the functional architecture of the brain, especially before the clinical expression becomes apparent, are not fully and consistently characterized. In this study, we sought to uncover functional changes in the brain in the heterozygous (HET) zQ175 delta-neo (DN) mouse model at 3, 6, and 10 months of age, using resting-state functional magnetic resonance imaging (RS-fMRI). This mouse model shows molecular, cellular and circuitry alterations that worsen through age. Motor function disturbances are manifested in this model at 6 and 10 months of age. Specifically, we investigated, longitudinally, changes in co-activation patterns (CAPs) that are the transient states of brain activity constituting the resting-state networks (RSNs). Most robust changes in the temporal properties of CAPs occurred at the 10-months time point; the durations of two anti-correlated CAPs, characterized by simultaneous co-activation of default-mode like network (DMLN) and co-deactivation of lateral-cortical network (LCN) and vice-versa, were reduced in the zQ175 DN HET animals compared to the wild-type mice. Changes in the spatial properties, measured in terms of activation levels of different brain regions, during CAPs were found at all three ages and became progressively more pronounced at 6-, and 10 months of age. We then assessed the cross-validated predictive power of CAP metrics to distinguish HET animals from controls. Spatial properties of CAPs performed significantly better than the chance level at all three ages with 80% classification accuracy at 6 and 10 months of age.

DRD1 signaling modulates TrkB turnover and BDNF sensitivity in direct pathway striatal medium spiny neurons

Disturbed motor control is a hallmark of Parkinson's disease (PD). Cortico-striatal synapses play a central role in motor learning and adaption, and brain-derived neurotrophic factor (BDNF) from cortico-striatal afferents modulates their plasticity via TrkB in striatal medium spiny projection neurons (SPNs). We studied the role of dopamine in modulating the sensitivity of direct pathway SPNs (dSPNs) to BDNF incultures of fluorescence-activated cell sorting (FACS)-enriched D1-expressing SPNs and 6-hydroxydopamine (6-OHDA)-treated rats. DRD1 activation causes enhanced TrkB translocation to the cell surface and increased sensitivity for BDNF. In contrast, dopamine depletion in cultured dSPN neurons, 6-OHDA-treated rats, and postmortem brain of patients with PD reduces BDNF responsiveness and causes formation of intracellular TrkB clusters. These clusters associate with sortilin related VPS10 domain containing receptor 2 (SORCS-2) in multivesicular-like structures, which apparently protects them from lysosomal degradation. Thus, impaired TrkB processing might contribute to disturbed motor function in PD.

Sensory Motor Function Disturbances in Mice Prenatally Exposed to Low Dose of Ethanol: A Neurobehavioral Study in Postnatal and Adult Stages

Prenatal alcohol exposure (PAE) refers to fetal exposure to alcohol during pregnancy through placental barrier transfer from maternal blood. The postnatal outcomes of PAE differ among exposed individuals and range from overt (serious) alcohol-related behavioral and neurophysiological impairments to covert (silenced) symptoms. The aims of the present investigation were to assess the postnatal neurobehavioral disturbances, particularly, motor coordination and sensory-motor function in mice with PAE. Female mice with positive vaginal plugs were divided into three groups: group 1: Et + Pyr: received two i.p injections of ethanol (1 g/kg) followed by pyrazole (100 mg/kg). Group 2: Pyr: received an i.p injection of pyrazole (100 mg/kg). Group 3: C: of saline controls received, in equal volume, saline solution (NaCl 0.9%). After birth, mice pups were weighed and subjected to behavioral tests for motor function screening using the motor ambulation test, cliff aversion, surface righting, and negative geotaxis, while at the adult stage, mice were subjected to the open field, rotarod, parallel bars, and static rods tests. Our data show an obvious decrement of body weight from the first post-natal day (P1) and continues over the adult stage. This was accompanied by an obvious impaired sensory-motor function which was maintained even at the adult stage with alteration of the locomotor and coordination abilities. The current data demonstrate the powerful neurotoxic effect of prenatal ethanol exposure on the sensory-motor and coordination functions, leading to suppose possible structural and/or functional neuronal disturbances, particularly the locomotor network.

Distribution of Cleaved SNAP-25 in the Rat Brain, following Unilateral Injection of Botulinum Neurotoxin-A into the Striatum.

In Parkinson's disease, hypercholinism in the striatum occurs, with the consequence of disturbed motor functions. Direct application of Botulinum neurotoxin-A in the striatum of hemi-Parkinsonian rats might be a promising anticholinergic therapeutic option. Here, we aimed to determine the spread of intrastriatally injected BoNT-A in the brain as well as the duration of its action based on the distribution of cleaved SNAP-25. Rats were injected with 1 ng of BoNT-A into the right striatum and the brains were examined at different times up to one year after treatment. In brain sections immunohistochemically stained for BoNT-A, cleaved SNAP-25 area-specific densitometric analyses were performed. Increased immunoreactivity for cleaved SNAP-25 was found in brain regions other than the unilaterally injected striatum. Most cleaved SNAP-25-ir was found in widespread areas ipsilateral to the BoNT-A injection, in some regions, however, immunoreactivity was also measured in the contralateral hemisphere. There was a linear relationship between the distance of a special area from the injected striatum and the time until its maximum averaged immunoreactivity was reached. Moreover, we observed a positive relationship for the area-specific distance from the injected striatum and its maximum immunoreactivity as well as for the connection density with the striatum and its maximum immunoreactivity. The results speak for a bidirectional axonal transport of BoNT-A after its application into the striatum to its widespread connected parts of the brain. Even one year after BoNT-A injection, cleaved SNAP-25 could still be detected.

Glycine receptor subunit-β-deficiency in a mouse model of spasticity results in attenuated physical performance, growth, and muscle strength.

Spasticity is the most common neurological disorder associated with increased muscle contraction causing impaired movement and gait. The aim of this study was to characterize the physical performance, skeletal muscle function, and phenotype of mice with a hereditary spastic mutation (B6.Cg-Glrbspa/J). Motor function, gait, and physical activity of juvenile and adult spastic mice and the morphological, histological, and mechanical characteristics of their soleus and gastrocnemius medialis muscles were compared with those of their wild-type (WT) littermates. Spastic mice showed attenuated growth, impaired motor function, and low physical activity. Gait of spastic mice was characterized by a typical hopping pattern. Spastic mice showed lower muscle forces, which were related to the smaller physiological cross-sectional area of spastic muscles. The muscle-tendon complex length-force relationship of adult gastrocnemius medialis was shifted toward shorter lengths, which was explained by attenuated longitudinal tibia growth. Spastic gastrocnemius medialis was more fatigue resistant than WT gastrocnemius medialis. This was largely explained by a higher mitochondrial content in muscle fibers and relatively higher percentage of slow-type muscle fibers. Muscles of juvenile spastic mice showed similar differences compared with WT juvenile mice, but these were less pronounced than between adult mice. This study shows that in spastic mice, disturbed motor function and gait is likely to be the result of hyperactivity of skeletal muscle and impaired skeletal muscle growth, which progress with age.

Functional and diagnostic significance of the fMRI-response type to motor loads in patients after traumatic brain damage

Aim of the study. Clarification of the functional and diagnostic significance of topography, or the type of fMRI-response recorded during active and passive hand movements in patients after traumatic brain injury.Material and methods. fMRI-responses gained during active and passive hand movements were analyzed in 40 patients with posttraumatic motor function disturbances and compared with results gained from 17 healthy volunteers (control group ).Results. In analyzed patients the increase of percentage of diffuse fMRI-response has been shown along with the areas of activation not typical for movement activation pattern typical healthy volunteers. The fMRI response type being it local or multifocal does not clearly correlate with the presence of motor function impairment (hemiparesis). However, it was found that with greater severity of hemiparesis there is a larger percentage of multifocal fMRI-response.The transition from a multifocal form of a motor fMRI-response to a local one observed in a dynamic study is accompanied by an improvement of patient’s general condition, a shift towards normalization of a number of morphofunctional indicators of the central nervous system, the tendency of regression of motor disorders.Conclusion. The increase of multifocal fMRI-responses in patients after traumatic brain injury is one of the signs of cerebral dysfunction. Dynamically observed transformation from multifocal to local fMRI-responses is associated with current or long-term improvement in motor activity as well, wit the regression of other clinical impairments and can be considered as prognostically positive sign of the course of post-traumatic illness.

Central post stroke pain: What are the new insights?

Stroke causes disability with high morbidity and mortality in the world, causes a variety of disabilities and symptoms including disturbances in motor function, sensory, and cognitive. Sensory disability in post stroke patient can be categorized into two group; the one is stimulated by peripheral mechanism which we often called post stroke pain, and another one is stimulated by central mechanism which we called central post stroke pain (CPSP). Pain after stroke is usually underdiagnosed and poorly understood. In 1906, CPSP was called the thalamus pain syndrome by Dejerine and Roussy, but then it is known that CPSP can also developed in extra-thalamic stroke lesion. The prevalence of CPSP is approximately 1-12% in all around the world. CPSP occurs in one-third of overall post-stroke pain cases. In most cases, the onset of CPSP is within 1 month and then the incidence decreases with time. The most common manifestations are allodynia and dysesthesia. The pathophysiology itself remains clearly unknown in detail. Various theories such as central sensitization, disinhibition of medial thalamus, and central imbalance theory thought to be contribute in CPSP pathophysiology. This complexity make CPSP very difficult to manage. Some pharmacotherapies and non-pharmacotherapies have been studied to relieve pain in order to improve the quality life of CPSP sufferers. The aim of this article is to discuss the general view of central post stroke pain to increase the understanding and awareness of health giver in order to give sooner and better management for patient that can affect prognosis of the patient.

Hot Cross Bun Sign: A Case Report of Multiple System Atrophy Presenting Predominantly as Respiratory Insufficiency

Multiple system atrophy (MSA) was a multisystem disorder usually associated with Parkinsonism, MSA-p subtype or with cerebellar ataxia, and MSA-c subtype. Respiratory insufficiency can be a part of the clinical manifestation of multiple-system atrophy. It can sometimes present as primary respiratory failure, mild motor function disturbance, or autonomic dysfunction. In this article, we present a case of a 60-year-old lady who was admitted to the intensive care unit with fever and shortness of breath of 3 days duration with an initial working diagnosis of community-acquired pneumonia requiring invasive mechanical ventilation. She had a history of daytime sleepiness and gait disturbance. A thorough neurological evaluation was done to ascertain the cause of difficulty in weaning her off the ventilator. Magnetic resonance imaging of the brain revealed atrophy of bilateral superior cerebellar peduncles and pons with the “hot cross bun sign” suggestive of multiple system atrophy. Thus, a prompt neurological examination and work-up, including brain imaging, are mandated in dealing with such cases of difficult to wean patients.

Сhronic gastritis: impaired motor-evacuation function of the stomach

The effect of morphological changes in the gastric mucosa on the motor-evacuation function of the stomach was evaluated in 90 patients with chronic atrophic gastritis and 93 patients with chronic non-atrophic gastritis aged 18 to 82 years. Motor function disturbances were discovered of 90% of patients with chronic atrophic gastritis and 80,6% with chronic non-atrophic gastritis. It was established that the pyloric insufficiency compared with its spasm was significantly more (p0,01) often in chronic atrophic gastritis. Insufficiency of the lower esophageal sphincter in patients with atrophic gastritis was significantly (p0,01). Insufficiency of the lower esophageal sphincter in combination with duodenogastric reflux in patients with chronic atrophic gastritis was significantly more (p0,01) often observed during diffuse atrophy, i. e. when mucous membrane of stomach corpus and antrum is involved in the process. With the localization of atrophy in the antrum alone, pyloric insufficiency was observed significantly more (p 0,01) often than spasm. Thus, an interrelation between the insufficiency of the lower esophageal and pyloric sphincters with the diffuse atrophic process has been established. There are no significant differences of disorders of gastric motor function in patients with different types of chronic gastritis. Accelerated evacuation from the stomach with localization of atrophy in the mucous membrane of the stomach corpus is more (p 0,01) often observed in patients with chronic atrophic gastritis.

Lumbar Facet Joint Cyst Caused by Calcium Pyrophosphate Arthropathy of the Spine: Case Report and Review of Literature

Background Data: Calcium pyrophosphate dihydrate (CPPD) deposition disease is a metabolic disorder caused by the deposition of CPPD crystals in the articular or periarticular structures that leads to inflammation of the joints. Spine affection is rare. Purpose: To present a rare case of lumbar facet joint cyst caused by calcium pyrophosphate arthropathy. Study Design: A case report with a brief review of the literature. Patient and Methods: Seventy-three-year-old man, who underwent PLIF L5/S1 ten years ago, presented with right L4 nerve root compression symptoms that have started two months ago. Clinical examination revealed no motor function disturbance but hypoesthesia in the L4 dermatome. He has no history of crystal deposition disorder. The patient underwent decompression and fusion at this level. Results: The symptoms were completely resolved postoperatively and after one-year follow-up. Histopathological examination of the cyst revealed fibrous granulation tissue. Examination of the tissue under polarized light showed positively birefringent, short blunt crystals of calcium pyrophosphate dihydrate. Conclusion: Calcium pyrophosphate arthropathy, although rare, should be incorporated into the differential diagnosis of cystic lesions of the facet joints. (2020ESJ221)

Effect of Short Period Simultaneous Stimulation of Transcranial Direct Current Stimulation (tDCS) on Occupational Therapy to Motor Function of Upper Extremity in Stroke Subject

ABSTRACTObjective: Stroke could cause upper extremity motor function disturbances that may affect to quality of life. The affected brain has an ability to get recovery by neuroplasticity process. Transcranial direct current stimulation (tDCS) is a non-invasive modality that could induce brain neuroplasticity Goal: To determine the effect of tDCS stimulation on recovery of upper extremity motor function in subacute ischaemic stroke patient. Methods: 22 stroke patients included in inclusion criteria, divided into 2 groups, control group and intervention group. Control group had occupational therapy for 5 days consecutively and intervention group had occupational therapy and tDCS stimulation simultaneously for 5 days consecutively. Upper extremity motor function was evaluated with Fugl-Meyer Assessment (FMA) before and after the treatment. Results: Significant improvement of FMA score on control group (p=0,018) and intervention group (p=0,000). Comparison of the result after the treatment revealed that the intervention group showed more significant improvement in FMA score than the control group (p=0,000). Conclusion: Application of tDCS stimulation on occupational therapy simultaneously showed improvement of upper extremity motor function in subacute ischaemic stroke patient better than only occupational therapy. Key Words: Transcranial direct current stimulation, occupational therapy, Fugl-Meyer Assessment, upper extremity motor function, subacute ischemic stroke.

Association Between Cerebral Small Vessel Disease and Central Motor Conduction Time in Patients with Vascular Risk

Background and Purpose: Cerebral small vessel disease (CSVD) is related to motor function disturbance. It includes several types: lacunar infarction, white matter hyperintensity, cerebral microbleeds (CMBs), and enlarged perivascular spaces (EPVS). Transcranial magnetic stimulation (TMS) has been successfully used to evaluate the function of the pyramidal tract. Central motor conduction time (CMCT) is one of the indicators of pyramidal tract dysfunction in motor evoked potential (MEP). The aim of this study was to investigate the association between each type of CSVD and CMCT. Methods: We enrolled 350 patients with vascular risk factors or a history of cerebrovascular events, who showed signs of CSVD in magnetic resonance imaging in the prospective registry. Among them, 138 patients agreed to the evaluation of MEP. CMCT, resting motor threshold (RMT), and silent period are indicators of the function of motor pathways in MEP. A total of 276 hemispheres were divided into 45 symptomatic hemispheres with a history of pyramidal tract dysfunction and 231 without it. Correlation between each type of CSVD and CMCT were examined in total, symptomatic, and asymptomatic hemispheres. Results: The mean age was 70.5 ± 10.3 (mean ± SD) years, and 89 (65%) were men. In the symptomatic hemisphere, CMCT and RMT were significantly higher than in the asymptomatic hemisphere. In the symptomatic hemisphere, significant association was observed between the number of EPVS in the white matter and CMCT (R2 = 0.201, p < .01). Conclusions: In the symptomatic hemispheres, CMCT was associated with the number of EPVS in the white matter. The EPVS in the white matter may be involved in the motor disturbance due to CSVD.

ПСИХОЛОГІЧНИЙ ЗМІСТ ФУНКЦІОНАЛЬНОЇ МЕТОДИКИ ВІДНОВЛЕННЯ РУХОВОЇ ФУНКЦІЇ ХВОРИХ НА ІШЕМІЧНИЙ ІНСУЛЬТ З УРАХУВАННЯМ ЇХНІХ ПСИХОФІЗІОЛОГІЧНИХ ОСОБЛИВОСТЕЙ

У статті зазначено, що найбільш частим і важким наслідком церебрального ішемічного інсульту є розлади рухової функції особистості. Характерний поліморфізм рухових порушень у хворих на церебральний ішемічний інсульт. При цьому загальним для них є лиш випадання або порушення довільних рухів (виникнення геміпарезу або геміплезії). Інші клінічні симптоми є великою мірою варіабельними і залежать певною мірою від розмірів ділянки ураження, її локалізації та ін. За оцінками різних науковців, стійкі розлади рухової функції спостерігаємо також у перші дні після захворювання в 70–80 % хворих, які пережили ішемічний інсульт.&#x0D; Розроблено «Функціональну методику відновлення рухової функції хворих на ішемічний інсульт з урахуванням їхніх психофізіологічних особливостей», засновану на психологічних принципах поетапності, послідовності та комплексності, а також на максимальному й адекватному психологічному впливі реабілітолога на пацієнта.&#x0D; Зазначено, що основними напрямами психотерапії та психокорекції в досліджуваних, котрі перенесли ішемічний інсульт, є допомога в усвідомленні пацієнтом його основних потреб, мотивів, настановлень, відносин; його внутрішніх конфліктів і механізмів психологічного захисту; особливостей поведінки та емоційного реагування, їх адекватності й реалістичності; корекція настановлень пацієнта; допомога у формулюванні та закріпленні адекватних форм поведінки на підставі особистісних досягнень у пізнавальній, мотиваційній, емоційній сферах; сприяння підвищенню позитивної мотивації на одужання й збільшення активності в боротьбі з хворобою на поведінковому рівні.

The supplementary motor area syndrome and the cerebellar mutism syndrome: a pathoanatomical relationship?

The supplementary motor area (SMA) syndrome affects adults after tumour resection in SMA neighbouring motor cortex. Cerebellar mutism syndrome (CMS) affects children after tumour resection in the posterior fossa. Both syndromes include disturbances in speech and motor function. The causes of the syndromes are unknown; however, surgical damage to the dentato-thalamo-cortical pathway (DTCP) has been associated with CMS. Thus, an anatomical link between the areas associated with the syndromes is possible. We discuss the syndromes and their possible relationship through the DTCP. We identified 61 articles (cohort studies, case reports and reviews) in MEDLINE and Embase searching for CMS, SMA syndrome or DTCP or synonyms and reviewed for evidence linking CMS and SMA. We found that SMA syndrome and CMS are similar regarding (1) surgical causation; (2) symptoms including speech impairment, disturbance in motor function and facial dysfunction; (3) delayed onset; (4) the courses of the syndromes are transient; and (5) long-term sequelae are seen in both. Relevant differences include age predominance of adults in SMA syndrome versus children in CMS. The similarities of the two syndromes could be traced back to their mutual connection through the DTCP and their membership to a cerebro-cerebellar circuit. The connectivity network could explain the emotional changes and speech reduction in CMS. The difference in time of post-surgical onset may be related to the anatomical distance between the surgical damage to the cerebellum and the SMA, respectively, and the effector neural loop underpinning symptoms.

Психологічні засади фізичної реабілітації хворих на ішемічний інсульт у процесі їх перебування на стаціонарному етапі лікування

The article deals with the problem of psychological principles of physical rehabilitation of patients with ischemic stroke in the process of their staying at the stationary stage of treatment. It was noted that the most frequent and severe consequence of cerebral ischemic stroke is the disorder of the motor functions of the personality. The characteristic feather is the polymorphism of motor disorders of patients with cerebral ischemic stroke. In this case, general for patients is only the loss or violation of arbitrary actions (in the cases of hemiparesis or hemiplegia). Other clinical symptoms are largely variable and depend on a certain extent of the size of affected area, also its localization. According to various authors, persistent disturbances of motor function are also observed in the first days afetr the disease (in 70–80% of cases of patients who had the ischemic stroke). In accordance with the purpose of the research and in order to solve the tasks, 50 patients with ischemic stroke participated in our experiment, they had disturbances in the area of the internal carotid artery in the acute and residual period, who were treated at the Ternopil Regional Communal Clinical Psycho-neurological Hospital during the period from January to December, 2018. Thus, most patients had a fairly low functional state, which required careful monitoring of the level of physical exercises which were being used. The latter also determined the method of further restoration measures (initial position for trainings, duration of trainings, the number of exercises performed by the symptom complexes, the frequency of repetition of exercises, the need for more frequent recording of changes in the frequency of heart rate and blood pressure in response to physical activity). The author of the article developed «Functional method of restoration of motor functions of patients with ischemic stroke, taking into account their psycho-physiological features». The main principles of this technique are: 1) stabilization of psycho-emotional state of the patient: reducing the level of anxiety, increasing the motivation to do physical exercises (to be included into the course of physical rehabilitation); 2) actualization of stable static and dynamic stereotypes of the patient in all initial positions of the body; 3) the restoration of a dynamic stereotype: considering the distal direction of muscles actions because it is prerequisite for providing motor actions; physical exercises must be carried out consistently, with gradual increasing of physical activity; 4) physical rehabilitation should be conducted to ensure the safety of rehabilitation measures, to avoid fatigue or over-stress of the cardiovascular system of the patient and to exceed the permissible level of increasing physical activity for the patient.It is noted that proposed functional method of physical rehabilitation of patients with ischemic stroke, based on mentioned principles, is differentiated, ontogenetically determined, which solves the problem of modeling the psycho-physiological hierarchical control of motor function from the nervous system, which takes into account the psycho-emotional state of the patient, which was actualized as a result of the disease.

Neurotoxic effects of mercury exposure in dental personnel.

Numerous studies have reported neurobehavioural effects in dental personnel occupationally exposed to chronic low levels of mercury (Hg). Hg exposure from dental work may also induce various chronic conditions such as elevation of amyloid protein expression, deterioration of microtubules and increase or inhibition of transmitter release at motor nerve terminal endings. Therefore, clinical studies of Hg toxicity in dentistry may provide new knowledge about disturbed metal homeostasis in neurodegenerative diseases such as Alzheimer's disease, multiple sclerosis and mood disorders. The purpose of this MiniReview is to evaluate the evidence of possible relevance between Hg exposure in dentistry and idiopathic disturbances in motor functions, cognitive skills and affective reactions, as well as dose-response relationships.

Disentangling motor planning and motor execution in unmedicated de novo Parkinson's disease patients: An fMRI study.

Many studies have used functional magnetic resonance imaging to unravel the neuronal underpinnings of motor system abnormalities in Parkinson's disease, indicating functional inhibition at the level of basal ganglia-thalamo-cortical motor networks. The study aim was to extend the characterization of functional motor changes in Parkinson's Disease by dissociating between two phases of action (i.e. motor planning and motor execution) during an automated unilateral finger movement sequence with the left and right hand, separately. In essence, we wished to identify neuronal dysfunction and potential neuronal compensation before (planning) and during (execution) automated sequential motor behavior in unmedicated early stage Parkinson's Disease patients. Twenty-two Parkinson's Disease patients (14 males; 53 ± 11 years; Hoehn and Yahr score 1.4 ± 0.6; UPDRS (part 3) motor score 16 ± 6) and 22 healthy controls (14 males; 49 ± 12 years) performed a pre-learnt four finger sequence (index, ring, middle and little finger, in order), either self-initiated (FREE) or externally triggered (REACT), within an 8-second time window. Findings were most pronounced during FREE with the clinically most affected side, where motor execution revealed significant underactivity of contralateral primary motor cortex, contralateral posterior putamen (sensorimotor territory), ipsilateral anterior cerebellum / cerebellar vermis, along with underactivity in supplementary motor area (based on ROI analyses only), corroborating previous findings in Parkinson's Disease. During motor planning, Parkinson's Disease patients showed a significant relative overactivity in dorsolateral prefrontal cortex (DLPFC), suggesting a compensatory overactivity. To a variable extent this relative overactivity in the DLPFC went along with a relative overactivity in the precuneus and the ipsilateral anterior cerebellum/cerebellar vermis Our study illustrates that a refined view of disturbances in motor function and compensatory processes can be gained from experimental designs that try to dissociate motor planning from motor execution, emphasizing that compensatory mechanisms are triggered in Parkinson's Disease when voluntary movements are conceptualized for action.

Significance of Biological Membranes for Accurate Computational Dosimetry of Low Frequency Electric Fields.

Computational dosimetry has become the main tool for estimating induced electric fields within brain tissues in transcranial direct current stimulation (tDCS) which is recently attracting the attention of researches for motor function disturbances such as Parkinson’s disease. This paper investigates the effect of including or excluding the very thin meninges in computing tDCS electric fields using CST software. For this purpose, two models of the brain with and without meninges were used to induce electric field with two DC current electrodes (2 mA) in regions of the model referring to M1 and Prefrontal Cortex (FP2) similar to tDCS. Considering meninges, the results have shown differences in the induced field showing that there might be problems with conventional models in which meninges are not taken into account.

Association between cerebral small vessel disease and central motor conduction time in patients with vascular risk factors

Background: Cerebral small vessel disease (CSVD) is related to motor function disturbance, typically vascular Parkinsonism. CSVD includes several types, lacunar infarction (LI), white matter hyperintensity (WMH), cerebral microbleeds (CMB) and etat cribre (EC).