Onset Of Tremor Research Articles

Recessive Variants in PIGG Cause a Motor Neuropathy with Variable Conduction Block, Childhood Tremor, and Febrile Seizures: Expanding the Phenotype.

Biallelic variants in phosphatidylinositol glycan anchor biosynthesis, class G (PIGG) cause hypotonia, intellectual disability, seizures, and cerebellar features. We present 8 patients from 6 families with a childhood-onset motor neuropathy and neurophysiology demonstrating variable motor conduction block and temporal dispersion. All individuals had a childhood onset tremor, 5 of 8 had cerebellar involvement, and 6 of 8 had childhood febrile seizures. All individuals have biallelic PIGG variants, including the previously reported pathogenic variant Trp505*, plus 6 novel variants. Null enzyme activity is demonstrated via PIGO/PIGG double knockout system for Val339Gly and Gly19Glu, and residual activity for Trp505* due to read-through. Emm negative blood group status was confirmed in 1 family. PIGG should be considered in unsolved motor neuropathy. ANN NEUROL 2024.

Baseline Depressive Symptoms as a Predictor of Incident Dementia in a Prospectively Followed Cohort of Elders with Essential Tremor

Introduction: Essential tremor (ET) patients may exhibit a variety of non-motor features, including cognitive decline and depressive symptoms. Studies of several neurodegenerative diseases link depression to cognitive decline, suggesting depression is an early marker of dementia. We examined whether baseline depressive symptoms predict incident dementia in elders with ET. Methods: Hundred and forty-one ET cases aged 70 years or older at baseline, enrolled in a prospective study of cognitive performance, took part in evaluations at baseline and at 18, 36, 54, and 72 months. Participants completed the Geriatric Depression Scale (GDS), a 30-item self-report measure of depressive symptoms, and a battery of neuropsychological tests and functional assessments, from which we derived cognitive diagnoses at each evaluation. Cox proportional hazards regression equations determined incident dementia risk based on participants’ baseline depression scores. Results: Mean baseline age was 81.5 ± 6.7 years. Higher baseline GDS scores were associated with increased risk of dementia in an unadjusted model (hazards ratio [HR] = 1.11, 95% confidence interval [CI] = 1.02–1.20, p = 0.01) and after controlling for baseline age, education, number of medications, and tremor onset age (HR = 1.13, 95% CI = 1.02–1.25, p = 0.02). Conclusion: Baseline depression scores predicted incident dementia in elders with ET. With each one-point increase in baseline depression score, there was a 13% increase in incident dementia risk. Given the published data that reported depression may be twice as high in elders with ET compared to controls, this association is particularly worrisome in the ET population.

Pharmacological screening of a new valproic acid derivative using the pharmacoencephalography method in rats

Introduction. The naïve Bayes classifier combined with principal component analysis allows to distinguish the effects of antipsychotic agents effectively as well as evaluate their dose-dependency based on their impact on electroencephalogram parameters in rats. Further development of this method requires its validation as an instrument for the screening of new understudied molecules. Valproic acid derivatives appear to be a promising neuropharmacological group as they exhibit not only antiepileptic activity but also mood-stabilizing, antimigraine, neuroprotective and analgesic effects.Aim. This work was carried out to perform the pharmacological screening of a valproic acid aminoester (AVA) that exhibits antidote properties in case of poisoning with anticholinesterase agents.Materials and methods. The experiments were conducted in white outbred rats with chronically implanted electrocorticographic electrodes. AVA was administered at doses of 0,5, 5 and 30 mg/kg. The training set, used as a reference to determine the pharmacological effects of each dose of the investigated substance, included matrixes of effects of 7 drugs: the antiepileptic agent sodium valproate, the D2-dopamine receptor blocker haloperidol, the M-cholinergic receptor blocker tropicamide, the H1-histamine receptor blocker chloropyramine, the acetylcholinesterase inhibitor galantamine, the sedative dexmedetomidine, and the anxiolytic phenazepam.Results and discussion. AVA at the dose of 0,5 mg/kg showed effects similar to those of sodium valproate, while a tenfold dose increase led to the predominance of an atropine-like effect. When administered at the dose of 30 mg/kg, the compound exhibited dexmedetomidine-like action. The central M-anticholinergic effect of AVA was confirmed by an arecoline test in mice, in which the substance at a dose of 88 mg/kg completely abolished the onset of tremor. Dexmedetomidine-like action was cancelled by the administration of atipamezole in equimolar quantities, which may indicate the potential сapability of AVA to activate α2-adrenergic receptors at a high dose. The results of molecular docking suggest that this effect is related specifically to the original aminoester molecule and not to its presumable active metabolites.Сonclusion. The obtained results confirm the effectiveness of the naïve Bayes classifier as an instrument for the prediction of the pharmacological activity of compounds based on their impact on electroencephalogram parameters in rats. Identification of new pharmacological effects of understudied compounds may widen the potential range of their clinical application as well as reveal probable adverse effects.

Bedside clinical assessment of patients with common upper limb tremor and algorithmic approach.

The diagnostic approach for patients with tremor is challenging due to the complex and overlapping phenotypes among tremor syndromes. The first step in the evaluation of tremor is to identify the tremulous movement and exclude the tremor mimics. The second step is to classify the tremor syndrome based on the characteristics of tremor from historical clues and focused examination (Axis 1). Comprehensive tremor examinations involve the assessment of tremor in different conditions (rest, action or mixed, position or task-specific), distribution of tremor (upper limb, lower limb, head, jaw), positive signs for functional tremor (FT) if suspected (distractibility, entrainment, co-contraction), and associated neurological signs including parkinsonism, dystonic posture, cerebellar/brainstem signs, neuropathy, and cognitive impairment. A pivotal feature in this step is to determine any distinct feature of a specific isolated or combined tremor syndrome. In this review, we propose an algorithm to assess upper limb tremors. Ancillary testing should be performed if clinical evaluation is unclear. The choice of investigation depends on the types of tremors considered to narrow down the spectrum of etiology (Axis 2). Laboratory blood tests are considered for acute onset and acute worsening of tremors, while structural neuroimaging is indicated in unilateral tremors with acute onset, nonclassical presentations, and a combination of neurological symptoms. Neurophysiological study is an important tool that aids in distinguishing between tremor and myoclonus, etiology of tremor and document specific signs of FT. Treatment is mainly symptomatic based depending on the etiology of the tremor and the patient's disabilities.

Analysis of gait characteristics and related factors in patients with Parkinson's disease based on wearable devices.

Postural instability and gait disorder dominant (PIGD) is one of the most common disabling symptoms of Parkinson's disease (PD), which seriously affects patients' quality of life. Therefore, it is essential to identify PIGD and develop targeted interventions to reduce the risk of PIGD in PD patients. This study aimed to investigate the gait characteristics of PD patients based on wearable devices and to establish a predictive model for their related influencing factors. The retrospective medical records of patients from January 2020 to September 2023 were collected, including 159 patients with PD (divided into PIGD [n=73] and non-PIGD [n=86] groups) and 200 healthy patients (as the healthy control group). Information from social demographic data, a blood test, scale scores, gait analysis based on wearable devices, white matter lesions, and the Fazekas scale was extracted and analyzed. Compared with the healthy control group, the mean step length, mean rate, mean angular velocity, and step length were lower in the PD group, while the mean steps were higher in the turning test. The incidence of PIGD was 46% in PD patients, and PD patients with the non-tremor onset mode were more likely to develop PIGD than those with the tremor onset mode. Compared to the non-PIGD group, the PIGD group showed more serious gait problems in different experimental tasks and had a higher Hoehn and Yahr (H-Y) stage, Hamilton Anxiety Scale (HAMA) score, Hamilton Depression Scale score, periventricular white matter (PVWM) score, deep white matter score, and Fazekas scale score, but they had lower hemoglobin levels, D-dimer levels, Tinetti Balance scores, Tinetti Gait scores, Berg Balance Scale scores, and Mini-Mental State Examination (MMSE) scores. Logistic regression analysis showed that the MMSE score was negatively correlated with the occurrence of PIGD, while the HAMA score, H-Y stage, PVWM score, and non-tremor form of onset were positively correlated with the occurrence of PIGD CONCLUSION: The incidence of gait disorder in PD patients is higher than that in the normal population. Moreover, cognitive dysfunction, anxiety state, H-Y stage, PVWM score, and the non-tremor mode of onset can be considered independent risk factors for PIGD.

New onset tremor in patients with COVID-19: can be a possible link with parkinsonism?

Aims: SARS-CoV-2 is a highly pathogenic member of the coronavirus family. We notice that some patients who were following in outpatient service have a new onset tremor. Our aim to describe these patients and interpreting new onset tremor after Covid-19 that possible link with parkinsonism. Methods: Forty-two patients with tremor who applied to Alanya Alaaddin Keykubat University Hospital neurology outpatient clinic between the 2021-2022 years were included the study. The data related to demographic characteristics, reasons for application of outpatient neurology clinic, pre-diagnosis and treatment were collected retrospectively. Results: The patients had a viral infection up to 3 months before the diagnosis of tremor was examined from the hospital system. It was determined that a total of 7 patients had viral infections due to upper respiratory infections and these were confirmed by polymerase chain reaction (PCR). Since two of these patients had concomitant thyroid dysfunction, one had diabetes and one had a history of acute cerebrovascular disorder, they were not included in the study. Covid-19 results were found to be positive wit PCR in 3 patients with a diagnosis of new onset tremor. It was determined in the neurology outpatient clinic notes of the patients that their complaints started after Covid-19. Conclusion: We haven’t enough data about Covid-19 yet but it should be included in the differential diagnosis of patients with new onset neurological symptoms, especially in epidemic situations.. Extensive clinical, neurological, and electrophysiological investigations of the patients may help to understand the virus's role in causing neurological manifestations

Canine idiopathic generalized tremor syndrome, immune-mediated?

Idiopathic generalized tremor syndrome is a disorder characterized by an acute onset of full-body tremors, sometimes accompanied by vestibulo-cerebellar signs, that is responsive to treatment with corticosteroids. Although considered to have an overall good outcome, relapsing and persistent mild clinical signs have been described. So far, little is known about the etiopathology of this syndrome, but it is believed to have an immune-mediated origin. In human medicine, description of numerous autoantibodies involved in certain non-infectious neurologic disorders has revolutionized understanding of their pathophysiology, diagnosis and treatment. In this multicenter retrospective study, we aimed to describe the clinical signs, course, and outcome of dogs with idiopathic generalized tremor syndrome and correlate potential findings with the presence or absence of autoantibodies associated with autoimmune cerebellar syndromes in humans. Information regarding signalment, history, clinical signs, laboratory findings, diagnostic imaging and testing for regional infectious diseases was gathered and the remaining serum and CSF samples were then analyzed for neural antibodies against targets associated with autoimmune encephalitic diseases of humans. Thirty-three dogs were included, and screening for neural antibodies was performed in 30 of those dogs. The analysis showed an increased titer of mGluR1 antibodies in two dogs, GFAP and later in the course of disease mGluR1 antibodies in one dog and an increase in unspecific autoantibodies which could not be further classified in two dogs. Dogs with detectable neural autoantibodies always had cerebrospinal fluid abnormalities in the form of a pleocytosis, with or without increased protein concentration, and tended to present with hyperthermia, potentially indicating a more severe clinical form of idiopathic generalized tremor syndrome in these cases. In conclusion, idiopathic generalized tremor syndrome is proposed to be an immune-mediated disorder potentially mediated by neural autoantibodies in a subgroup of dogs.

The time interval between injection of nicotine and tremor initiation: a new index for evaluating nicotine efficacy in rodents

Tremor is one of the effects of nicotine as a toxic substance, especially in animal models. The intensity and duration of tremors were used to evaluate the effect of nicotine on locomotor activity in laboratory animals. In our observations, the time interval between nicotine injection and the onset of tremor changed depending on the dose. Therefore, by increasing the dose of nicotine in rats, the time interval of tremor onset was also shortened. These results suggest that the time interval between nicotine injection and the onset of tremors can be used as a complementary index for better evaluation of nicotine-derived motor disturbances.

Parkinson’s disease tremor prediction using EEG data analysis-A preliminary and feasibility study

PurposeTremor is one of the hallmarks of Parkinson’s disease (PD) that does not respond effectively to conventional medications. In this regard, as a complementary solution, methods such as deep brain stimulation have been proposed. To apply the intervention with minimal side effects, it is necessary to predict tremor initiation. The purpose of the current study was to propose a novel methodology for predicting resting tremors using analysis of EEG time-series.MethodsA modified algorithm for tremor onset detection from accelerometer data was proposed. Furthermore, a machine learning methodology for predicting PD hand tremors from EEG time-series was proposed. The most discriminative features extracted from EEG data based on statistical analyses and post-hoc tests were used to train the classifier for distinguishing pre-tremor conditions.ResultsStatistical analyses with post-hoc tests showed that features such as form factor and statistical features were the most discriminative features. Furthermore, limited numbers of EEG channels (F3, F7, P4, CP2, FC6, and C4) and EEG bands (Delta and Gamma) were sufficient for an accurate tremor prediction based on EEG data. Based on the selected feature set, a KNN classifier obtained the best pre-tremor prediction performance with an accuracy of 73.67%.ConclusionThis feasibility study was the first attempt to show the predicting ability of EEG time-series for PD hand tremor prediction. Considering the limitations of this study, future research with longer data, and different brain dynamics are needed for clinical applications.

A prospective cohort study of familial versus sporadic essential tremor cases: Do clinical features evolve differently across time?

BackgroundAlthough essential tremor (ET) is often divided into familial and sporadic cases, few data compare the evolution of clinical features in these groups over time. Leveraging data from a prospective, longitudinal study, we present analyses of the evolution of a broad range of cognitive, motor (i.e., tremor, tandem gait) and other features (e.g., disability) of ET. MethodsSixty-six familial and 23 sporadic ET cases completed in-home evaluations at baseline and 18, 36, and 54-month follow-ups. Assessments included detailed neuropsychological testing and videotaped neurological examinations. Analyses compared the longitudinal course of 16 clinical features in familial and sporadic cases. ResultsBaseline mean age was 75.2 ± 8.8 years and mean observation period was 4.7 ± 0.3 years. Tremor onset age was lower and childhood onset more common in familial than sporadic cases (p's = 0.02). Longitudinal analyses revealed no significant differences between clinical features displayed by familial and sporadic cases, or differences between the patterns of change in clinical features observed in these groups across time. Sporadic cases' daily activity skills declined significantly, whereas familial cases' did not, p's = 0.04 and 0.34, respectively; however, this finding was non-significant when controlling for false discovery rate. Several additional non-significant trends were noted. ConclusionFamilial and sporadic ET cases differed in onset age, and in the prevalence of childhood tremor onset. Although a number of interesting trends were observed, no significant differences in the evolution of clinical features over time in patients with and without a family history of ET were revealed.

Analysis of Semiology, Lesion Topography and Treatment Outcomes: A Prospective Study on Post Thalamic Stroke Holmes Tremor.

Holmes tremor (HT) comprises rest, postural and intention tremor subtypes, usually involving both proximal and distal musculature. Perturbations of nigro-striatal pathways might be fundamental in the pathogenesis of HT along with cerebello-thalamic connections. Nine patients with an HT phenotype secondary to thalamic stroke were included. Epidemiological and clinical records were obtained. Structural and functional brain imaging were performed with magnetic resonance imaging (MRI) or computed tomography (CT) and positron emission tomography (PET), respectively. Levodopa was administered in sequentially increasing dosage, with various other drugs in case of inadequate response. Longitudinal follow-up was performed for at least three months. The essential tremor rating assessment scale (TETRAS) was used for assessment. The mean latency from stroke to tremor onset was 50.4 ± 30.60 days (range 21-90 days). Dystonia was the most frequently associated hyperkinetic movement (88.8%). Tremor was bilateral in 22.2% of participants. Clinical response was judged based on a reduction in the TETRAS score by a prefixed value (≥ 30%), pertaining to which 55.5% (n = 5) of subjects were classified as responders and the rest as non-responders. The responders showed improvement with significantly lower doses of levodopa than the remaining nonresponders (240 ± 54.7 mg vs. 400 ± 40.8 mg; p = 0.012). Although levodopa is useful in HT, augmenting the dosage of levodopa beyond a certain point might not benefit patients clinically. Topography of vascular lesions within the thalamus might additionally influence the phenomenology of HT.

SAT553 A Case of Metastatic Functional Papillary Thyroid Cancer in the Setting of Graves’ Disease

Abstract Disclosure: N. Manuel: None. S.J. Sternlieb: None. J. Dendy: None. Q.Z. Iqbal: None. A Case of Metastatic Functional Papillary Thyroid Cancer In the Setting of Graves’ DiseaseManuel, N., Sternlieb, S., Grissett, B., Iqbal, Q., Dendy, J. Background: Grave’s disease (GD) and papillary thyroid cancer (PTC) can be concomitant diseases. We report a rare case of metastatic PTC with concomitant GD leading to symptomatic hyperthyroidism despite total thyroidectomy. Clinical Case: A 58-year-old woman with longstanding history of thyroid nodules and left dominant nodule with benign biopsy on multiple occasions presented to her PCP with dyspnea, weight loss and globus sensation. CT of the chest was obtained revealing tracheal deviation from neck mass, mediastinal lymphadenopathy and multiple pulmonary nodules. Biopsy of lung nodule showed follicular features consistent with tumor cells of thyroid origin. She had a total thyroidectomy with central neck dissection with a final diagnosis of left sided 5 cm infiltrative follicular variant papillary thyroid carcinoma. Thyroid hormone replacement was initiated and on follow up 4 weeks later she was noted to be tachycardic at weight-based dose. At that time TSH was <0.010 uIU/mL (0.400 - 4.00), free T4 was 1.96 ng/dL (0.71 – 1.51) and Thyroglobulin was found to be 31516 ng/dL (Athyrotic <0.1). Prior to planned RAI she developed symptoms of dyspnea on exertion and edema and was sent to the ER for abnormal D. Dimer. Workup for PE was negative including CTA of the chest. A follow up visit showed further symptoms of hyperthyroidism with worsening fatigue, dyspnea, palpitations and new onset tremor. Levothyroxine dose was decreased further but 2 weeks later she returned to the ER with worsened thyroid function tests, and she was admitted for symptomatic hyperthyroidism. Levothyroxine was held and she was placed on PTU and propranolol. Given the overt symptomatic hyperthyroidism there were concerns for either Jod-Basedow phenomenon from iodine load with recent imaging or for hyperfunctioning PTC metastasis as the cause. Thyrotropin receptor antibody level was checked to further clarify and was elevated at 22 IU/L (0.00 – 1.75) consistent with GD. An I-131 diagnostic whole-body scan demonstrated small foci of right thyroid bed remnant and iodine-avid metastases involving mediastinal nodal disease as well as pulmonary and osseous metastases. She then underwent RAI therapy with 104.5 mCi I-131 without Thyrogen stimulation. Follow up whole body scan showed persistence of iodine-avid metastasis without any new foci of uptake compared to pretreatment scans. Conclusion: Although the coexistence of them is rare, GD should be put into the differential of rapidly progressive metastatic PTC especially if patient markedly hyperthyroid on lower doses of thyroid hormone. While functional thyroid carcinoma is rare, with less than 100 cases in literature, thorough investigation should be completed in order to not miss this concomitant disease process. Presentation Date: Saturday, June 17, 2023

FRI435 A Grave Case Of Gynecomastia

Abstract Disclosure: S. Seltzer: None. A. illiams: None. T. Kader: None. Background: Gynecomastia is a common endocrinology referral. Our team saw a patient in the clinic with an unusual presentation. Clinical Case: A 28 year old male presented with worsening painful gynecomastia affecting one breast initially but eventually progressing to both breasts. His secondary concern was a 40lb weight loss and new onset tremor. He declined hypogonadal symptoms, palpitations, or new testicular growth. Exam revealed a resting pulse of 120 b.p.m., a palpable goiter, visible tremor, hyperdynamic heart sounds and bilateral tender gynecomastia. Labs revealed normal FSH, LH and hCG, high total testosterone (TT), thyroxine (T4) and triiodothyronine (T3) with positive thyroid receptor antibodies. Methimazole and beta blockade were started. He did develop an episode of atrial fibrillation requiring admission. Due to medication intolerance and patient preference the decision was made for total thyroidectomy. Three months post-surgery there was complete resolution of hyperthyroidism and gynecomastia.The differential for true gynecomastia is broad. The initial diagnostic approach includes a thorough history and physical exam followed by measuring serum testosterone (T), LH, hCG and estradiol (E2). Increased LH and low T indicates hypogonadism. Normal values may suggest an idiopathic cause. Elevated hCG warrants testicular imaging and if negative, chest and abdominal imaging to rule out extragonadal germ cell tumors. Elevated total T and LH should prompt measurement of TSH and T4 and if normal androgen resistance should be suspected. Elevated E2 and low/low normal LH should prompt testicular imaging and if normal an adrenal CT to rule out an adrenal neoplasm. If LH and T are low, prolactin should be measured as well as dedicated pituitary imaging.Any state which induces an increased E to T ratio may cause gynecomastia. The true pathophysiology in hyperthyroidism driving the increased sex hormone binding globulin (SHBG) production is unknown. It is postulated that this increase is driven by increased transcription and translation of hepatocyte nuclear factor-4ɑ secondary to elevated T41. SHBG more readily binds androgens than estrogens leading to a relative decrease in free T (FT). The lower FT levels result in negative feedback to the pituitary gland which causes increases in LH resulting in production of androgens, estradiol and peripheral aromatases. The increase in peripheral aromatization of testosterone leads to further elevation of the free estrogen levels. Conclusion: Hyperthyroidism should always be in the differential of gynecomastia as in our case the presentation may be atypical.

Lithium-induced subacute diencephalic angio endotheliopathy.

A 65-years-old woman with bipolar affective disorder presented to our ED with a severe lithium intoxication and the recent onset of confusion, clumsiness, and tremors. Symptoms worsened to stupor and anarthria immediately after hospital admission. Gadolinium-enhanced brain Magnetic Resonance Imaging (MRI) showed signal hyperintensity involving both thalami in T2weighted (T2w)/Fluid Attenuated Inversion Recovery sequences (right > left), restricted areas of proton diffusivity at the level of both occipital lobes and a sharp contrast enhancement of thalami, rhombencephalon, and of leptomeninges from either the temporal, parietal, occipital lobes as well as from the cerebellar folia (right > left). These findings were consistent with a severe form of Posterior Encephalopathy known as Subacute Diencephalic Angio Endotheliopahty (SDAE). In addition, Magnetic Resonance Angiography revealed thrombosis of the right transverse and sigmoidal sinuses up to confluence with the jugular vein. The MRI picture resolved one month later after a course of high dosage dexamethasone. The patient deceased one month after discharge, mainly due to Diabetes Insipidusassociated hypernatremia. Dissecting the "Pandora's box" represented by complex MRI findings (SDAE and sinus thrombosis) in lithium-induced neurotoxicity is fundamental in timely recognizing this threating but potentially reversible clinical picture.

Assessing network-based earthquake early warning systems in low-seismicity areas

Earthquake early warning (EEW) technology, designed to alert the public of earthquake risks after initial P-wave detection but before the onset of strong tremors, has developed rapidly. Methodologies from various fields are combined in EEW systems to estimate earthquake locations, magnitudes, and expected intensities based on the initial P-wave data. These systems operate automatically because prompt responses are required. However, as no common evaluation framework for EEW system verification exists, potentially divergent evaluations from reviewers or countries could ensue. Moreover, evaluating EEW systems is more complicated when the target area does not experience frequent earthquakes. We aimed to establish a guidance review process for low-seismicity areas to ensure reliable and stable integrated EEW system operation. We incorporated management aspects through actual system operator surveillance and designed an EEW assessment process based on feedback from our surveys. Using this approach, we created a comprehensive and well-informed evaluation process that considers the diverse perspectives of experts involved in EEWs. Our proposed assessment method allows for a uniform and consistent evaluation process, regardless of changes in the methods or technologies used by EEW systems. The method aims to guide EEW system assessments in low-seismicity areas.

Complete SAMD12 repeat expansion sequencing in a four-generation BAFME1 family with anticipation.

Benign adult familial myoclonic epilepsy type 1 (BAFME1) is an autosomal dominant, adult-onset neurological disease caused by SAMD12 repeat expansion. In BAFME1, anticipation, such as the earlier onset of tremor and/or seizures in the next generation, was reported. This could be explained by intergenerational repeat instability, leading to larger expansions in successive generations. We report a four-generation BAFME1-affected family with anticipation. Using Nanopore long-read sequencing, detailed information regarding the sizes, configurations, and compositions of the expanded SAMD12 repeats across generations was obtained. Unexpectedly, a grandmother-mother-daughter triad showed similar repeat structures but with slight repeat expansions, despite quite variable age of onset of seizures (range: 52-14 years old), implying a complex relationship between the SAMD12 repeat expansion sequence and anticipation. This study suggests that different factor(s) from repeat expansion could modify the anticipation in BAFME1.

Integrative Brain States Facilitate the Expression of Parkinson's Tremor.

Parkinson's disease (PD) rest tremor emerges from pathological activity in the basal ganglia and cerebello-thalamo-cortical circuits. A well-known clinical feature is the waxing and waning of PD tremor amplitude, but the mechanisms that drive this variability are unclear. Previous work has shown that arousal amplifies PD tremor by increasing between-network connectivity. Furthermore, brain states in PD are biased toward integration rather than segregation, a pattern that is also associated with increased arousal. The aim was to test the hypothesis that fluctuations in integrative brain states and/or arousal drive spontaneous fluctuations in PD rest tremor. We compared the temporal relationship between cerebral integration, the ascending arousal system, and tremor, both during cognitive load and in the resting state. In 40 tremor-dominant PD patients, we performed functional magnetic resonance imaging using concurrent tremor recordings and proxy measures of the ascending arousal system (pupil diameter, heart rate). We calculated whole-brain dynamic functional connectivity and used graph theory to determine a scan-by-scan measure of cerebral integration, which we related to the onset of tremor episodes. Fluctuations in cerebral integration were time locked to spontaneous changes in tremor amplitude: cerebral integration increased 13 seconds before tremor onset and predicted the amplitude of subsequent increases in tremor amplitude. During but not before tremor episodes, pupil diameter and heart rate increased and correlated with tremor amplitude. Integrative brain states are an important cerebral environment in which tremor-related activity emerges, which is then amplified by the ascending arousal system. New treatments focused on attenuating enhanced cerebral integration in PD may reduce tremor. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Development of abnormalities at the neuromuscular junction in the SOD1-G93A mouse model of ALS: dysfunction then disruption of postsynaptic structure precede overt motor symptoms.

The ultimate deficit in amyotrophic lateral sclerosis (ALS) is neuromuscular junction (NMJ) loss, producing permanent paralysis, ultimately in respiratory muscles. However, understanding the functional and structural deficits at NMJs prior to this loss is crucial for therapeutic strategy design. Should early interventions focus on reversing denervation, or supporting largely intact NMJs that are functionally impaired? We therefore determined when functional and structural deficits appeared in diaphragmatic NMJs relative to the onset of hindlimb tremor (the first overt motor symptoms) in vivo in the SOD1-G93A mouse model of ALS. We employed electrophysiological recording of NMJ postsynaptic potentials for spontaneous and nerve stimulation-evoked responses. This was correlated with fluorescent imaging microscopy of the postsynaptic acetylcholine receptor (AChR) distribution throughout the postnatal developmental timecourse from 2 weeks to early symptomatic ages. Significant reduction in the amplitudes of spontaneous miniature endplate potentials (mEPPs) and evoked EPPs emerged only at early symptomatic ages (in our colony, 18-22 weeks). Reductions in mEPP frequency, number of vesicles per EPP, and EPP rise time were seen earlier, at 16weeks, but this reversed by early symptomatic ages. However, the earliest and most striking impairment was an inability to maintain EPP amplitude during a 20 Hz stimulus train, which appeared 6 weeks before overt in vivo motor symptoms. Despite this, fluorescent α-bungarotoxin labelling revealed no systematic, progressive changes in 11 comprehensive NMJ morphological parameters (area, shape, compactness, number of acetylcholine receptor, AChR, regions, etc.) with disease progression. Rather, while NMJs were largely normally-shaped, from 16 weeks there was a progressive and substantial disruption in AChR concentration and distribution within the NMJ footprint. Thus, NMJ functional deficits appear at least 6 weeks before motor symptoms in vivo, while structural deficits occur 4 weeks later, and predominantly within NMJs. These data suggest initial therapies focused on rectifying suboptimal NMJ function could produce effective relief of symptoms of weakness.

Acute onset of muscle tremors, vomiting, hyporexia, and lethargy in a 6-month-old female spayed Terrier mix

Acute onset of muscle tremors, vomiting, hyporexia, and lethargy in a 6-month-old female spayed Terrier mix

Spinocerebellar ataxia 21 and phenotypic variability within a single family (P9-11.004)

<h3>Objective:</h3> We describe four patients within a family who presented to our movement disorders centers for evaluation of unsteady gait, tremor, and cognitive impairment found to have the same pathogenic variant in TMEM240. We describe their clinical courses and response to treatments to include posterior subthalamic area deep brain stimulation (PSA DBS) and provide accompanying video. <h3>Background:</h3> Spinocerebellar ataxia 21 (SCA21) is a rare cause of autosomal dominant ataxia with few patients (~50) published. It is an early-onset, slowly progressive cerebellar ataxia and may also have tremor, parkinsonism, oculomotor abnormalities, cognitive impairment, and psychiatric conditions. Given its rarity, the neurodevelopmental phenotype has not been well defined and phenotypic variability within the same variant has not yet described. <h3>Design/Methods:</h3> The index case, 12 year-old girl, presented with mild intellectual disability, severe action tremor since infancy, oculomotor abnormalities, anxiety, and depression. The full brother was noted to have mild action tremor since early childhood, speech delay and growth delay. The paternal half-brother presented with progressively worsening action tremor since early childhood which became impairing in adolescence as well as similar oculomotor abnormalities, learning disabilities, ADHD, and OCD. The father of the patients had onset of mild non-progressive action tremor of the hands since age 8, progressive ataxia, mild parkinsonism, mild intellectual disability and new onset progressive memory impairment. All patients were found to have the same pathogenic variant in TMEM240 (c.196G&gt;A p.G66R)). <h3>Results:</h3> The index patient tried numerous oral medications as well as botulinum neurotoxin (BoNT) injections without improvement. She underwent PSA DBS with marked improvement in tremor. Tremor in the paternal half-brother responded well to BoNT injections. The father underwent treatment for parkinsonism with carbidopa-levodopa and was started on rivastigmine without improvement. <h3>Conclusions:</h3> SCA21 is a slowly progressive autosomal dominant spinocerebellar ataxia with variable neurodevelopmental phenotypes including multiple movement disorders within the same variant. <b>Disclosure:</b> Dr. Hull has received publishing royalties from a publication relating to health care. Dr. Parnes has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Teva Pharmaceuticals. Dr. Parnes has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Teva Pharmaceuticals. The institution of Dr. Parnes has received research support from NIH. The institution of Dr. Parnes has received research support from Alexion. Dr. Jankovic has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Revance. Dr. Jankovic has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Revance, Allergan. The institution of Dr. Jankovic has received research support from Baylor College of Medicine. Dr. Jankovic has received research support from Abbvie. The institution of Dr. Jankovic has received research support from Abbvie.