Feasibility and Challenges of Performing Magnetoencephalography Experiments in Children With Arthrogryposis Multiplex Congenita

Arthrogryposis multiplex congenita (AMC) has recently drawn substantial attention from researchers and clinicians. New effective surgical and physiotherapeutic methods have been developed to improve the quality of life of patients with AMC. While it is clear that all these interventions should strongly rely on the plastic reorganization of the central nervous system, almost no studies have investigated this topic. The present study demonstrates the feasibility of using magnetoencephalography (MEG) to investigate brain activity in young AMC patients. We also outlined the general challenges and limitations of electrophysiological investigations on patients with arthrogryposis. We conducted MEG recordings using a 306-channel Elekta Neuromag VectorView system during a cued motor task performance in four patients with arthrogryposis, five normally developed children, and five control adults. Following the voice command of the experimenter, each subject was asked to bring their hand toward their mouth to imitate the self-feeding process. Two patients had latissimus dorsi transferred to the biceps brachii position, one patient had a pectoralis major transferred to the biceps brachii position, and one patient had no elbow flexion restoration surgery before the MEG investigation. Three patients who had undergone autotransplantation prior to the MEG investigation demonstrated activation in the sensorimotor area contralateral to the elbow flexion movement similar to the healthy controls. One patient who was recorded before the surgery demonstrated subjectively weak distributed bilateral activation during both left and right elbow flexion. Visual inspection of MEG data suggested that neural activity associated with motor performance was less pronounced and more widely distributed across the cortical areas of patients than of healthy control subjects. In general, our results could serve as a proof of principle in terms of the application of MEG in studies on cortical activity in patients with AMC. Reported trends might be consistent with the idea that prolonged motor deficits are associated with more difficult neuronal recruitment and the spatial heterogeneity of neuronal sources, most likely reflecting compensatory neuronal mechanisms. On the practical side, MEG could be a valuable technique for investigating the neurodynamics of patients with AMC as a function of postoperative abilitation.

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Lesion in the lateral cerebellum specifically produces overshooting of the toe trajectory in leading forelimb during obstacle avoidance in the rat

Journal of Neurophysiology ◽

10.1152/jn.01048.2012 ◽

2013 ◽

Vol 110 (7) ◽

pp. 1511-1524 ◽

Cited By ~ 15

Author(s):

Sho Aoki ◽

Yamato Sato ◽

Dai Yanagihara

Keyword(s):

Obstacle Avoidance ◽

Posterior Parietal Cortex ◽

Primary Motor Cortex ◽

Biceps Brachii ◽

Elbow Flexion ◽

Emg Activity ◽

Visual Guidance ◽

The Central Nervous System ◽

Posterior Parietal

During locomotion, stepping over an obstacle under visual guidance is crucial to continuous safe walking. Studies of the role of the central nervous system in stepping movements have focused on cerebral cortical areas such as the primary motor cortex and posterior parietal cortex. There is speculation that the lateral cerebellum, which has strong anatomical connections with the cerebral cortex, also plays a key role in stepping movements over an obstacle, although this function of the lateral cerebellum has not yet been elucidated. Here we investigated the role of the lateral cerebellum during obstacle avoidance locomotion in rats with a lateral cerebellar lesion. A unilateral lesion in the lateral cerebellum did not affect limb movements during overground locomotion. Importantly, however, the lesioned animals showed overshooting of the toe trajectory specific to the leading forelimb ipsilateral to the lesion when stepping over an obstacle, and the peak toe position, in which the toe is maximally raised during stepping, shifted away from the upper edge of the obstacle. Recordings of EMG activity from elbow flexor and extensor muscles suggested that the overshooting toe trajectory in the ipsilateral leading forelimb possibly resulted from sustained elbow flexion and delayed elbow extension following prolonged activity of the biceps brachii. These results suggest that the lateral cerebellum specifically contributes to generating appropriate toe trajectories in the ipsilateral leading forelimb and to controlling related muscle activities in stepping over an obstacle, especially when accurate control of the distal extremity is achieved under visual guidance.

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Meningeal Carcinomatosis for Prostate Adenocarcinoma Mimicking Chronic Subdural Hematoma: Case Report and Literature Review

Arquivos Brasileiros de Neurocirurgia Brazilian Neurosurgery ◽

10.1055/s-0040-1713092 ◽

2021 ◽

Author(s):

Tiago Silva Holanda Ferreira ◽

Gilnard Caminha de Menezes Aguiar ◽

Daniel Gurgel Fernandes Távora ◽

Lucas Alverne Freitas de Albuquerque ◽

Stélio da Conceição Araújo Filho

Keyword(s):

Case Report ◽

Subdural Hematoma ◽

Specific Antigen ◽

Chronic Subdural Hematoma ◽

Radical Resection ◽

Prostate Adenocarcinoma ◽

Meningeal Carcinomatosis ◽

Motor Deficits ◽

Friable Material ◽

The Central Nervous System

Abstract Introduction Cerebral metastases are the most common cancer of the central nervous system (CNS). Meningeal infiltration by neoplasms that did not originate in the CNS is a rare fact that is present in 0.02% of the autopsies.Epidemiologically, the radiological presentation mimicking a subdural hematoma is even more uncommon. We report a case of meningeal carcinomatosis by an adenocarcinoma of the prostate mimicking a chronic subdural hematoma. Case Report A 60-year-old male patient was diagnosed with prostate cancer in 2011. He underwent radical resection of the prostate, as well as adjuvant hormonal therapy and chemotherapy.Five years later, the patient presented peripheral facial paralysis that evolved with vomiting and mental confusion. Tomography and magnetic resonance imaging scans confirmed the subdural collection.At surgery, the dura was infiltrated by friable material of difficult hemostasis. The anatomicopathological examination showed atypical epithelial cells. The immunohistochemistry was positive for prostate-specific antigen (PSA) and other key markers, and it was conclusive for meningeal carcinomatosis by a prostate adenocarcinoma. Discussion Meningeal carcinomatosis presents clinically with headache, motor deficits, vomiting, changes in consciousness and seizures.The two most discussed mechanisms of neoplastic infiltration are the hematogenous route and retrograde drainage by the vertebral venous plexus. Conclusion Variable clinical presentations may occur in dural metastases; however, the radiological presentation as subdural hematoma is rare. There are few descriptions of cases like this one in the literature.To support the diagnosis, the previous medical history is as important as the complementary exams and the radiological findings, because the symptoms are common at the neurological emergency. To our knowledge, this is the first report of a prostate neoplasm mimicking chronic subdural hematoma in Brazil.

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Muscle length and joint angle influence spinal but not corticospinal excitability to the biceps brachii across forearm postures

Journal of Neurophysiology ◽

10.1152/jn.00620.2018 ◽

2019 ◽

Vol 122 (1) ◽

pp. 413-423 ◽

Cited By ~ 2

Author(s):

Davis A. Forman ◽

Daniel Abdel-Malek ◽

Christopher M. F. Bunce ◽

Michael W. R. Holmes

Keyword(s):

Isometric Contraction ◽

Elbow Joint ◽

Joint Angle ◽

Biceps Brachii ◽

Motor Evoked Potentials ◽

Muscle Length ◽

Elbow Flexion ◽

Corticospinal Excitability ◽

Biceps Brachii Muscle ◽

Spinal Excitability

Forearm rotation (supination/pronation) alters corticospinal excitability to the biceps brachii, but it is unclear whether corticospinal excitability is influenced by joint angle, muscle length, or both. Thus the purpose of this study was to separately examine elbow joint angle and muscle length on corticospinal excitability. Corticospinal excitability to the biceps and triceps brachii was measured using motor evoked potentials (MEPs) elicited via transcranial magnetic stimulation. Spinal excitability was measured using cervicomedullary motor evoked potentials (CMEPs) elicited via transmastoid electrical stimulation. Elbow angles were manipulated with a fixed biceps brachii muscle length (and vice versa) across five unique postures: 1) forearm neutral, elbow flexion 90°; 2) forearm supinated, elbow flexion 90°; 3) forearm pronated, elbow flexion 90°; 4) forearm supinated, elbow flexion 78°; and 5) forearm pronated, elbow flexion 113°. A musculoskeletal model determined biceps brachii muscle length for postures 1–3, and elbow joint angles ( postures 4–5) were selected to maintain biceps length across forearm orientations. MEPs and CMEPs were elicited at rest and during an isometric contraction of 10% of maximal biceps muscle activity. At rest, MEP amplitudes to the biceps were largest during supination, which was independent of elbow joint angle. CMEP amplitudes were not different when the elbow was fixed at 90° but were largest in pronation when muscle length was controlled. During an isometric contraction, there were no significant differences across forearm postures for either MEP or CMEP amplitudes. These results highlight that elbow joint angle and biceps brachii muscle length can each independently influence spinal excitability. NEW & NOTEWORTHY Changes in upper limb posture can influence the responsiveness of the central nervous system to artificial stimulations. We established a novel approach integrating neurophysiology techniques with biomechanical modeling. Through this approach, the effects of elbow joint angle and biceps brachii muscle length on corticospinal and spinal excitability were assessed. We demonstrate that spinal excitability is uniquely influenced by joint angle and muscle length, and this highlights the importance of accounting for muscle length in neurophysiological studies.

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Mechanical Evaluation of the Pronator Teres Rerouting Tendon Transfer

Journal of Hand Surgery (European Volume) ◽

10.1016/j.jhsb.2004.01.004 ◽

2004 ◽

Vol 29 (3) ◽

pp. 257-262 ◽

Cited By ~ 18

Author(s):

H. E. J. VEEGER ◽

M. KREULEN ◽

M. J. C. SMEULDERS

Keyword(s):

Biceps Brachii ◽

External Rotation ◽

Three Dimensional ◽

Muscle Length ◽

Biomechanical Model ◽

Elbow Flexion ◽

Axial Rotation ◽

Original Position ◽

Pronator Quadratus ◽

Pronator Teres

We simulated pronator teres rerouting using a three-dimensional biomechanical model of the arm. Simulations comprised the evaluation of changes in muscle length and the moment arm of pronator teres with changes in forearm axial rotation and elbow flexion. The rerouting of Pronator Teres was simulated by defining a path for it through the interosseous membrane with re-attachment to its original insertion. However the effect of moving the insertion to new positions, 2 cm below and above, the original position was also assessed. The effect on total internal rotation and external rotation capacity was determined by calculating the potential moments for pronator teres, supinator, pronator quadratus, biceps brachii and brachioradialis. Pronator teres was found to be a weak internal rotator in extreme pronation, but a strong internal rotator in neutral rotation and in supination. After rerouting pronator teres was only a strong external rotator in full pronation and not at other forearm positions, where the effect of rerouting was comparable to a release procedure.

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The Portable Warrior Test of Tactical Agility: A Novel Functional Assessment That Discriminates Service Members Diagnosed With Concussion From Controls

Military Medicine ◽

10.1093/milmed/usab346 ◽

2021 ◽

Author(s):

Amy Seal Cecchini ◽

Julianna Prim ◽

Wanqing Zhang ◽

Courtney H Harrison ◽

Karen L McCulloch

Keyword(s):

Construct Validity ◽

Functional Assessment ◽

Motor Task ◽

Service Members ◽

Control Group ◽

Readiness Assessment ◽

Mobility Assessment ◽

Healthy Control ◽

High Level ◽

Return To Duty

ABSTRACT Introduction Return-to-duty (RTD) readiness assessment for service members (SM) following concussion requires complex clinical considerations. The Portable Warrior Test of Tactical Agility (POWAR-TOTAL) is a functional assessment which improves on previous laboratory-based RTD assessments. Methods Sixty-four SM diagnosed with concussion and 60 healthy control (HC) SM participated in this study. Group differences were analyzed to validate the POWAR-TOTAL. The High-level Mobility Assessment Test (HiMAT) was used to examine concurrent construct validity. An exploratory logistic regression analysis examined predictive validity. Results The groups were demographically well-matched except for educational level. POWAR-TOTAL measures were statistically significantly different between the groups with moderate to large effect sizes. Concussed participants were less likely to be able to complete all trials of the POWAR-TOTAL. Motor scores correlated highly with HiMAT scores. POWAR-TOTAL motor task performance and membership in the control group was significantly associated with self-reported physical readiness to deploy. Conclusion The POWAR-TOTAL is a clinically feasible, military relevant assessment that is sensitive to differences between concussed and HC SM. This analysis supports the discriminant and construct validity of the POWAR-TOTAL, and may be useful for medical providers evaluating RTD readiness for SM who have sustained a concussion.

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Immune system markers of neuroinflammation in patients with clinical diagnose of neuromyelitis optica

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x2008000500013 ◽

2008 ◽

Vol 66 (3b) ◽

pp. 678-684 ◽

Cited By ~ 8

Author(s):

Soniza Vieira Alves-Leon ◽

Maria Lucia Vellutini Pimentel ◽

Gabrielle Sant'Anna ◽

Fabíola Rachid Malfetano ◽

Cláudio Duque Estrada ◽

...

Keyword(s):

Neuromyelitis Optica ◽

B Lymphocyte ◽

Demyelinating Disease ◽

Interferon Γ ◽

Interleukin 4 ◽

Control Group ◽

Regulatory Cells ◽

Immunological Parameters ◽

Healthy Control ◽

The Central Nervous System

Neuromyelitis optica (NMO) is an inflammatory, demyelinating disease of the central nervous system characterized by the association of a serious myelitis and unilateral or bilateral optic neuritis. The present study aimed to analyze the immunological parameters of NMO patients with diagnosis established based on Wingerchuck et al. (1999) criteria. Production of IgG and IgA antibodies to antigens of MBP, PLP 95-116, MOG 92-106, and the cytokines interleukin-4 (IL-4) and interferon-γ (INF-γ) were assessed by Elisa assay. The cohort was formed by 28 NMO patients and a matched healthy control group. NMO patients had significant high levels of IgG to MOG (p<0.0001), PLP (p=0.0002) and MBP (p<0.0001), and solely IgA to MBP (p<0.0001). INF-γ (p=0.61) levels were similar to healthy controls. Increased production of IL-4 (p=0.0084) indicates an important role for this cytokine in the activation of Th2 regulatory cells and of the IgA producers B lymphocyte indicating activation of humoral immunity.

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Does Motor Learning Occur in the Spinal Cord?

The Neuroscientist ◽

10.1177/107385849700300510 ◽

1997 ◽

Vol 3 (5) ◽

pp. 287-294 ◽

Cited By ~ 47

Author(s):

V. Reggie Edgerton ◽

Roland R. Roy ◽

Ray De Leon Niranjala Tillakaratne ◽

John A. Hodgson

Keyword(s):

Spinal Cord ◽

Motor Task ◽

Lumbar Spinal Cord ◽

Lumbosacral Spinal Cord ◽

Patterns Of Use ◽

The Neural Network ◽

The Central Nervous System ◽

Network Plasticity ◽

Lumbar Spinal ◽

The Brain

It is becoming clear that the plasticity of the sensory-motor networks of the adult mammalian lumbosacral spinal cord is much greater than and is more dependent on the specific patterns of use than has been previously assumed. Using a wide variety of experimental paradigms in which the lumbar spinal cord is isolated from the brain, it has been shown that the lumbosacral spinal cord can learn to execute stepping or standing more successfully if that specific task is practiced. It also appears that the sensory input associated with the motor task and/or the manner in which it is interpreted by the spinal cord are important components of the neural network plasticity. Early evidence suggests that several neurotransmitter systems in the spinal cord, to include glycinergic and GABAergic systems, adapt to repetitive use. These studies extend a growing body of evidence suggesting that memory and learning are widely distributed phenomena within the central nervous system. NEUROSCIENTIST 3:287–294, 1997

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Octopamine and occupancy: an aminergic mechanism for intruder–resident aggression in crickets

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2010.2099 ◽

2010 ◽

Vol 278 (1713) ◽

pp. 1873-1880 ◽

Cited By ~ 50

Author(s):

Jan Rillich ◽

Klaus Schildberger ◽

Paul A. Stevenson

Keyword(s):

Receptor Antagonist ◽

Adrenergic Receptor ◽

Receptor Blocker ◽

Field Crickets ◽

Behavioural Strategy ◽

Neuronal Mechanisms ◽

Selective Depletion ◽

Octopamine Receptor ◽

The Central Nervous System ◽

Aggressive Motivation

Aggression is a behavioural strategy for securing resources (food, mates and territory) and its expression is strongly influenced by their presence and value. While it is known that resource holders are generally highly aggressive towards intruding consexuals and usually defeat them, the underlying neuronal mechanisms are not known. In a novel intruder–resident paradigm for field crickets ( Gryllus bimaculatus ), we show that otherwise submissive losers of a preceding aggressive encounter readily fight and often defeat aggressive winners after occupying an artificial shelter. This aggression enhancing effect first became evident after 2 min residency, and was maximal after 15 min, but absent 15 min after shelter removal. The residency effect was abolished following non-selective depletion of biogenic amines from the central nervous system using reserpine, or semi-selective depletion of octopamine and dopamine using α-methyl-tyrosine, but not following serotonin depletion using α-methyl-tryptophan. The residency effect was also abolished by the treatment with phentolamine, an α-adrenergic receptor antagonist, or epinastine, a highly selective octopamine receptor blocker, but not by propranolol, a ß-adrenergic receptor antagonist, or by yohimbine, an insect tyramine receptor blocker. We conclude that crickets evaluate residency as a rewarding experience that promotes aggressive motivation via a mechanism involving octopamine, the invertebrate analogue of noradrenaline.

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A scalar Poincaré map for struggling in Xenopus tadpoles

10.1101/540971 ◽

2019 ◽

Author(s):

Mark Olenik ◽

Conor Houghton

Keyword(s):

Fixed Points ◽

Activity Patterns ◽

Synaptic Depression ◽

The Body ◽

Synaptic Conductance ◽

Inhibitory Synapses ◽

Minimal Network ◽

Cell Network ◽

Neuronal Mechanisms ◽

The Central Nervous System

AbstractSynaptic plasticity is widely found in many areas of the central nervous system. In particular, it is believed that synaptic depression can act as a mechanism to allow simple networks to generate a range of different firing patterns. The simplicity of the locomotor circuit in hatchling Xenopus tadpoles provides an excellent place to understand such basic neuronal mechanisms. Depending on the nature of the external stimulus, tadpoles can generate two types of behaviours: swimming when touched and slower, stronger struggling movements when held. Struggling is associated with rhythmic bends of the body and is accompanied by anti-phase bursts in neurons on each side of the spinal cord. Bursting in struggling is thought to be governed by a short-term synaptic depression of inhibition. To better understand burst generation in struggling, we study a minimal network of two neurons coupled through depressing inhibitory synapses. Depending on the strength of the synaptic conductance between the two neurons, such a network can produce symmetric n - n anti-phase bursts, where neurons fire n spikes in alternation, with the period of such solutions increasing with the strength of the synaptic conductance. Using a fast/slow analysis, we reduce the multidimensional network equations to a scalar Poincaé burst map. This map tracks the state of synaptic depression from one burst to the next, and captures the complex bursting dynamics of the network. Fixed points of this map are associated with stable burst solutions of the full network model, and are created through fold bifurcations of maps. We prove that the map has an infinite number of stable fixed points for a finite coupling strength interval, suggesting that the full two-cell network also can produce n - n bursts for arbitrarily large n. Our findings further support the hypothesis that synaptic depression can enrich the variety of activity patterns a neuronal network generates.

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