Negative Myoclonus: Neurophysiological Study and Clinical Impact in Progressive Myoclonus Ataxia.

INTRODUCTION: Negative myoclonus (NM) is an involuntary movement caused by a sudden interruption of muscular activity, resulting in gait problems and falls. OBJECTIVE: To establish frequency, clinical impact, and neurophysiology of NM in progressive myoclonus ataxia (PMA) patients. METHODS: Clinical, neurophysiological, and genetic data of 14 PMA individuals from University Medical Centre Groningen (UMCG) Expertise Center Movement Disorder Groningen were retrospectively collected. Neurophysiological examination included video-electromyography-accelerometry assessment in all patients and electroencephalography (EEG) examination in 13 individuals. Jerk-locked (or silent period-locked) back-averaging and cortico-muscular coherence (CMC) analysis aided the classification of myoclonus. RESULTS: NM was present in 6 (NM+) and absent in 8 (NM-) PMA patients. NM+ individuals have more frequent falls (100% vs. 37.5%) and higher scores on the Gross Motor Function Classification System (GMFCS) (4.3 ±0.74 vs. 2.5 ±1.2) than NM- individuals. Genetic background of NM+ included GOSR2 and SEMA6B, while that of NM- included ATM, KCNC3, NUS1, STPBN2, and GOSR2. NM was frequently preceded by positive myoclonus (PM) and silent-period length was between 88 and 194 ms. EEG epileptiform discharges were associated with NM in 2 cases. PM was classified as cortical in 5 NM+ and 2 NM- through EEG inspection, jerk-locked back-averaging, or CMC analysis. DISCUSSION: Neurophysiological examination is crucial for detecting NM that could be missed on clinical examination due to a preceding PM. Evidence points to a cortical origin of NM, an association with more severe motor phenotype, and suggests the presence of genetic disorders causing either a PMA or progressive myoclonus epilepsy, rather than pure PMA phenotype. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Wearable monitoring of positive and negative myoclonus in progressive myoclonic epilepsy type 1.

OBJECTIVE: To develop and test wearable monitoring of surface electromyography and motion for detection and quantification of positive and negative myoclonus in patients with progressive myoclonic epilepsy type 1 (EPM1). METHODS: Surface electromyography and three-dimensional acceleration were measured from 23 EPM1 patients from the biceps brachii (BB) of the dominant and the extensor digitorum communis (EDC) of the non-dominant arm for 48 hours. The patients self-reported the degree of myoclonus in a diary once an hour. Severity of myoclonus with action was evaluated by using video-recorded Unified Myoclonus Rating Scale (UMRS). Correlations of monitored parameters were quantified with the UMRS scores and the self-reported degrees of myoclonus. RESULTS: The monitoring-based myoclonus index correlated significantly (p < 0.001) with the UMRS scores (ρ = 0.883 for BB and ρ = 0.823 for EDC) and with the self-reported myoclonus degrees (ρ = 0.483 for BB and ρ = 0.443 for EDC). Ten patients were assessed as probably having negative myoclonus in UMRS, while our algorithm detected that in twelve patients. CONCLUSIONS: Wearable monitoring was able to detect both positive and negative myoclonus in EPM1 patients. SIGNIFICANCE: Our method is suitable for quantifying objective, real-life treatment effects at home and progression of myoclonus.

[Response to perampanel in a patient with chronic post-hypoxic myoclonus]. / Respuesta a perampanel en un paciente con mioclono posthipóxico crónico.

INTRODUCTION: Chronic post-hypoxic myoclonus is a condition in which the predominant clinical picture is myoclonus following hypoxic brain damage, usually due to cardiorespiratory arrest. It is a condition that is usually treated with antiepileptic drugs, in most cases with a modest clinical response. CASE REPORT: We report the case of a patient who started with jerking movements, compatible with myoclonus in the four limbs and the face the day after recovering from a cardiorespiratory arrest. An electroencephalogram was performed during which the myoclonias were recorded with no electrical correlates. During admission, and in successive visits after discharge, different antiepileptic treatments were tried for the myoclonias, which were refractory and affected the patient's quality of life. Two years after onset, treatment with perampanel up to a dose of 4 mg was initiated and the patient reported a significant clinical improvement, as evidenced in the visits. CONCLUSIONS: Perampanel may be an effective alternative for the treatment of myoclonias in patients with chronic post-hypoxic myoclonus.

TITLE: Respuesta a perampanel en un paciente con mioclono posthipóxico crónico.Introducción. El mioclono posthipóxico crónico es un cuadro cuya clínica predominante son las mioclonías que acontecen tras un daño cerebral hipóxico, generalmente por parada cardiorrespiratoria. Es una entidad que se trata generalmente con fármacos antiepilépticos, con una modesta respuesta clínica en la mayoría de los casos. Caso clínico. Paciente que comienza con movimientos de sacudidas, compatibles con mioclonías de las cuatro extremidades y faciales al día siguiente de una parada cardiorrespiratoria recuperada. Se realizó un electroencefalograma durante el cual se registraron las mioclonías sin presentar correlato eléctrico. Durante el ingreso, y en sucesivas visitas tras el alta, se probaron diferentes tratamientos antiepilépticos para las mioclonías, que fueron refractarias y comportaron una afectación de la calidad de vida del paciente. Tras dos años de evolución, se inició tratamiento con perampanel hasta una dosis de 4 mg y el paciente refirió una mejoría clínica importante, evidenciada en consultas. Conclusiones. El perampanel puede suponer una alternativa eficaz para el tratamiento de las mioclonías en pacientes con mioclono posthipóxico crónico.

Epilepsy With Eyelid Myoclonia (Jeavons Syndrome).

The purpose of this review is to provide a comprehensive update and highlight the distinct electroclinical features and discuss recent advances in the etiology, pathophysiology, and management strategies of epilepsy with eyelid myoclonia. Recent studies indicate that variations of certain genes including CHD2 (chromodomain helicase DNA-binding protein 2), KCNB1, KIAA2022, and NAA10 may occur in these patients. It has been postulated that the occipital cortex may play a role in the pathophysiology. Recent studies of functional imaging and connectivity of neuronal electrical activity have provided additional evidence to support this hypothesis. The frontal cortex has additionally been implicated, and it has been suggested that the epileptic cortex may extend beyond the occipital cortex to involve the posterior temporal cortex. We update the management strategies and describe tools that may predict seizure persistence. Epilepsy with eyelid myoclonias, or Jeavons syndrome, is an idiopathic generalized epilepsy characterized by the triad of eyelid myoclonia with or without absence seizures, eyelid closure-elicited electroencephalographic (EEG) paroxysms (epileptiform discharges and/or seizures), and photosensitivity. This condition may account for up to 13% of generalized epilepsies. However, it is frequently under-reported and under-recognized. Many of the patients develop medically refractory epilepsy, and seizures tend to persist throughout life.

Propriospinal Myoclonus.

Propriospinal myoclonus (PSM) consists of paroxysmal and sudden jerks involving axial flexion trunk and hip muscles, conditioning sudden myoclonias of the trunk and arms/limbs, both spontaneous and triggered by sensory stimulations, emerging in relaxed wakefulness typically during the transition between wake and sleep. Generally, PSM originates from a thoracic myelomere and spreads caudally and rostrally, provoking flexion and/or extension movements, leading to jumps or trunk jerks. They appear triggered by the lying-down position and disappear when the subject stands up. The main consequences are the difficulties in sleep start and the reappearance during the period of wakefulness after sleep onset.

Eight years follow-up of a generalized epilepsy patient with eating-induced late-onset epileptic spasms and atypical absence with myoclonic jerks.

PURPOSE: Eating epilepsy was previously known as a kind of focal reflex epilepsy. However, the development of eating-induced multiple generalized seizures and the associated EEG changes were rarely reported. Herein, we present a 13-year-old generalized epilepsy patient with eating-induced generalized seizures since the age of 5. CASE PRESENTATION: The 13-year-old male patient had suffered from late-onset eating-induced epileptic spasms during the meal since the age of 5. Meanwhile, he also experienced spontaneous epileptic spasms during the period of sleep. The seizure frequency and type gradually increased from 7 years of age. In addition to epileptic spasms, he started experiencing atypical absence with myoclonic jerks during the meal. Ictal EEG presented as the appearance of an irregular slow-wave mixed with generalized polyspike wave with the intake of food, and gradually evolved to bursts of generalized polyspike wave complexes. At the end of the meal, the EEG returned to normal. Nevertheless, at the age of 13, his seizure frequency increased and appeared new seizure type, and besides epileptic spasm and atypical absence, he began to experience myoclonic seizure during sleep and awaking-generalized tonic-clonic seizure in the morning. In this period he started taking valproic acid, topiramate and clonazepam, and his seizure frequency was reduced. CONCLUSION: In conclusion, this case demonstrated the variability of eating induced multiple generalized seizure types, and eight years follow-up also indicates that generalized epilepsy progressed with age. The EEG and clinical changes of our patient contribute to a better understanding of the electro-clinical features of eating-induced multiple generalized seizures and the course of generalized epilepsy with such seizures.

Neurological and Neuropsychiatric Impacts of COVID-19 Pandemic.

BACKGROUND: Albeit primarily a disease of respiratory tract, the 2019 coronavirus infectious disease (COVID-19) has been found to have causal association with a plethora of neurological, neuropsychiatric and psychological effects. This review aims to analyze them with a discussion of evolving therapeutic recommendations. METHODS: PubMed and Google Scholar were searched from 1 January 2020 to 30 May 2020 with the following key terms: "COVID-19", "SARS-CoV-2", "pandemic", "neuro-COVID", "stroke-COVID", "epilepsy-COVID", "COVID-encephalopathy", "SARS-CoV-2-encephalitis", "SARS-CoV-2-rhabdomyolysis", "COVID-demyelinating disease", "neurological manifestations", "psychosocial manifestations", "treatment recommendations", "COVID-19 and therapeutic changes", "psychiatry", "marginalised", "telemedicine", "mental health", "quarantine", "infodemic" and "social media". A few newspaper reports related to COVID-19 and psychosocial impacts have also been added as per context. RESULTS: Neurological and neuropsychiatric manifestations of COVID-19 are abundant. Clinical features of both central and peripheral nervous system involvement are evident. These have been categorically analyzed briefly with literature support. Most of the psychological effects are secondary to pandemic-associated regulatory, socioeconomic and psychosocial changes. CONCLUSION: Neurological and neuropsychiatric manifestations of this disease are only beginning to unravel. This demands a wide index of suspicion for prompt diagnosis of SARS-CoV-2 to prevent further complications and mortality.

Les impacts neurologiques et neuropsychiatriques d'une infection à la COVID-19. CONTEXTE: Bien qu'il s'agisse principalement d'une maladie des voies respiratoires, la maladie infectieuse à coronavirus apparue en 2019 (COVID-19) s'est avérée avoir un lien de causalité avec une pléthore d'impacts d'ordre neurologique, neuropsychiatrique et psychologique. Cette étude entend donc analyser ces impacts tout en discutant l'évolution des recommandations thérapeutiques se rapportant à cette maladie. MÉTHODES: Les bases de données PubMed et Google Scholar ont été interrogées entre les 1er janvier et 30 mai 2020. Les termes clés suivants ont été utilisés : « COVID-19 ¼, « SRAS ­ CoV-2 ¼, « Pandémie ¼, « Neuro ­ COVID ¼, « AVC ­ COVID ¼, « Épilepsie ­ COVID ¼, « COVID ­ encéphalopathie ¼, « SRAS ­ CoV-2 ­ encéphalite ¼, « SRAS ­ CoV-2 ­ rhabdomyolyse ¼, « COVID ­ maladie démyélinisante ¼, « Manifestations neurologiques ¼, « Manifestations psychosociales ¼, « Recommandations thérapeutiques ¼, « COVID-19 et changement thérapeutiques ¼, « Psychiatrie ¼, « Marginalisés ¼, « Télémédecine ¼, « Santé mentale ¼, « Quarantaine ¼, « Infodémique ¼ et « Médias sociaux ¼. De plus, quelques articles de journaux relatifs à la pandémie de COVID-19 et à ses impacts psychosociaux ont également été ajoutés en fonction du contexte. RÉSULTATS: Il appert que les manifestations neurologiques et neuropsychiatriques des infections à la COVID-19 sont nombreuses. Les caractéristiques cliniques d'une implication des systèmes nerveux central et périphérique sautent désormais aux yeux. Ces caractéristiques ont fait l'objet d'une brève analyse systématique à l'aide de publications scientifiques. En outre, la plupart des impacts d'ordre psychologique de cette pandémie se sont révélés moins apparents que les changements réglementaires, socioéconomiques et psychosociaux. CONCLUSION: Les manifestations neurologiques et neuropsychiatriques de cette maladie ne font que commencer à être élucidées. Cela exige donc une capacité accrue de vigilance en vue d'un diagnostic rapide, et ce, afin de prévenir des complications additionnelles et une mortalité accrue.

Movement Disorders in Chronic Kidney Disease - A Descriptive Review.

OBJECTIVES: The objective of this study is to describe the mechanism of damage to subcortical structures in chronic kidney disease (CKD) and to describe the range of movement disorders associated with CKD. MATERIALS AND METHODS: We have reviewed the Medline literature up to January of 2020 using key words movement disorders and chronic kidney disease. The reviewed articles were studied for mechanisms of subcortical damage in CKD as well as type of the reported movements, their frequency and updated treatment. RESULTS: The search revealed 183 articles most of them dealing with restless legs syndrome. The damage to basal ganglia in CKD resulted from several mechanisms including accumulation of nitro tyrosine caused by reactive oxygen species and action of uremic toxins leading to endothelial damage and dysfunction of blood-brain barrier. Involuntary movements in CKD include restless legs syndrome (RLS), myoclonus, asterixis, dystonia, chorea, tremor, and Parkinsonism. CONCLUSIONS: Chronic kidney disease can cause several abnormal involuntary movements via damaging basal ganglia and subcortical structures. The most common movement disorders in CKD are RLS, myoclonus and asterixis. Restless legs syndrome and myoclonus when severe, need and respond to treatment. Movement disorders in CKD improve with improvement of kidney function.

Alcohol-Responsive Hyperkinetic Movement Disorders-a Mechanistic Hypothesis.

Patients with essential tremor, vocal tremor, torticollis, myoclonus-dystonia and posthypoxic myoclonus often benefit in a surprisingly rapid and robust manner from ingestion of a modest amount of alcohol (ethanol). Despite considerable investigation, the mechanism of ethanol's ability to produce this effect remains a mystery. In this paper, we review the pharmacology of ethanol and its analogue GHB (or sodium oxybate), summarize the published literature of alcohol-responsive hyperkinetic movement disorders, and demonstrate videos of patients we have treated over the last fifteen years with either an ethanol challenge or with chronic sodium oxybate therapy. We then propose a novel explanation for this phenomenon-namely, that ingestion of modest doses of ethanol (or sodium oxybate) normalizes the aberrant motor networks underling these disorders. We propose that alcohol and its analogues improve clinical symptoms and their physiologic correlate by restoring the normal firing pattern of the major outflow pathways of the cerebellum (the Purkinje cells and deep cerebellar nuclei), We present evidence to support this hypothesis in animal models and in affected patients, and suggest future investigations to test this model.

Treatment of Post-Hypoxic Myoclonus using Pallidal Deep Brain Stimulation Placed Using Interventional MRI Methods.

Background: Post-hypoxic myoclonus (PHM) is characterized by generalized myoclonus after hypoxic brain injury. Myoclonus is often functionally impairing and refractory to medical therapies. Deep brain stimulation (DBS) has been used to treat myoclonus-dystonia, but few cases of PHM have been described. Case report: A 33-year-old woman developed severe, refractory generalized myoclonus after cardiopulmonary arrest from drowning. We performed MRI-guided asleep bilateral pallidal DBS placement, resulting in improvement in action myoclonus at one year. Discussion: Our case contributes to growing evidence for DBS for PHM. Interventional MRI guided DBS technique can be used for safe and accurate lead placement. Highlights: We report a case of a patient who developed post-hypoxic myoclonus after cardiopulmonary arrest from drowning, who later underwent deep brain stimulation to treat refractory myoclonus. This is the first case to describe asleep, interventional MRI-guided technique for implanting DBS leads in post-hypoxic myoclonus.

Continuous epileptic negative myoclonus as the first seizure type in atypical benign epilepsy with centrotemporal spikes.

To figure out which diagnosis is more suitable and which antiepileptic drugs are more sensitive to epileptic negative myoclonus (ENM) as the first seizure type in atypical benign epilepsy with centrotemporal spikes.We reviewed the electroencephalogram (EEG) database of Linyi People's Hospital Affiliated to Shandong University and medical records of patients with ENM onset. The characteristics of epileptic seizures, onset age, treatment process, growth and development history, past disease history, family history, degree of mental deterioration, cranial imaging, and video-EEG were studied retrospectively and followed up.There were 4 cases with ENM onset and 1 with continuous ENM, 3 males and 1 female. The onset age was from 2 years 3 months to 8 years 7 months. The cranial magnetic resonance imaging (MRI) and developmental quotient, as well as the family, personal, and past disease history, were normal. Frequent falls and drops were the main clinical manifestations. Five months after the onset of ENM, case 1 had focal seizures in sleep. ENM was the first and only manifestation in all the other 3 children. Discharges of interictal EEG were in bilateral rolandic areas, especially in midline areas (Cz, Pz), electrical status epilepticus in sleep was found in 3 cases. One child was sensitive to levetiracetam, the other 3 were sensitive to clonazepam.ENM can affect the upper or lower extremities. ENM as the first or only symptom was a special phenomenon in benign epilepsy with centrotemporal spikes (BECTS) variants. Ignorance of midline spikes mainly in Cz or Pz in BECTS might lead to missed diagnosis of ENM. Whether benzodiazepines are viable as a choice of BECTS variants with electrical status epilepticus in sleep when ENM is the first symptom still needs a large sample evidence-based observation.

Biomarkers in functional movement disorders: a systematic review.

Functional movement disorders (FMD) are proposed to reflect a specific problem with voluntary control of movement, despite normal intent to move and an intact neural capacity for movement. In many cases, a positive diagnosis of FMD can be established on clinical grounds. However, the diagnosis remains challenging in certain scenarios, and there is a need for predictors of treatment response and long-term prognosis.In this context, we performed a systematic review of biomarkers in FMD. Eighty-six studies met our predefined criteria and were included.We found fairly reliable electroencephalography and electromyography-based diagnostic biomarkers for functional myoclonus and tremor. Promising biomarkers have also been described for functional paresis, gait and balance disorders. In contrast, there is still a lack of diagnostic biomarkers of functional dystonia and tics, where clinical diagnosis is often also more challenging. Importantly, many promising findings focus on pathophysiology and reflect group-level comparisons, but cannot differentiate on an individual basis. Some biomarkers also require access to time-consuming and resource-consuming techniques such as functional MRI.In conclusion, there are important gaps in diagnostic biomarkers in FMD in the areas of most clinical uncertainty. There is also is a lack of treatment response and prognostic biomarkers to aid in the selection of patients who would benefit from rehabilitation and other forms of treatment.