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Developmental Medicine and Child... Feb 2023To evaluate early dystonic features in children and adolescents with SGCE-myoclonus-dystonia.
AIM
To evaluate early dystonic features in children and adolescents with SGCE-myoclonus-dystonia.
METHOD
In this cross-sectional study, 49 patients (26 females and 23 males) with SGCE-myoclonus-dystonia (aged 15y 2mo, SD 12y) with childhood-onset (2y 10mo, SD 1y 10mo) dystonia were examined using a standardized video recorded protocol. Dystonia was rated using the Writer's Cramp and Gait Dystonia Rating Scales. Disability and impairment for handwriting and walking were also rated.
RESULTS
Dystonia was present at rest (n=1), posture (n=12), and during specific motor tasks (n=45) such as writing (n=35), walking (n=23), and running (n=20). Most children reported disability while performing these tasks. Early dystonic patterns were identified for writer's cramp and gait dystonia, the latter named the 'circular shaking leg', 'dragging leg', and 'hobby-horse gait' patterns. Sensory tricks were used by five and eight children to improve dystonia and myoclonus during writing and walking respectively. The rating scales accurately measured the severity of action dystonia and correlated with self-reported disability.
INTERPRETATION
Children with SGCE-myoclonus-dystonia show recognizable dystonic patterns and sensory tricks that may lead to an early diagnosis and timely therapeutic approach. Isolated writer's cramp is a key feature in childhood and should prompt SCGE analysis. The proposed action dystonia scales could be used to monitor disease course and response to treatment.
WHAT THIS PAPER ADDS
Most children with SGCE-myoclonus-dystonia got writer's cramp and had walking and running dystonia. Writer's cramp was a key feature and should prompt SGCE genetic investigation. 'Circular shaking leg', 'dragging leg', and 'hobby-horse gait' were recognized as early gait patterns. Children used sensory tricks to improve myoclonus and dystonia, suggesting common pathophysiological mechanisms. Action dystonia rating scales are valid tools to assess severity in children.
Topics: Child; Female; Humans; Male; Cross-Sectional Studies; Dystonia; Dystonic Disorders; Movement Disorders; Myoclonus; Sarcoglycans
PubMed: 35723607
DOI: 10.1111/dmcn.15298 -
Clinical Neurophysiology : Official... Dec 2023Cortical myoclonus is thought to result from abnormal electrical discharges arising in the sensorimotor cortex. Given the ease of recording of cortical discharges,... (Review)
Review
Cortical myoclonus is thought to result from abnormal electrical discharges arising in the sensorimotor cortex. Given the ease of recording of cortical discharges, electrophysiological features of cortical myoclonus have been better characterized than those of subcortical forms, and electrophysiological criteria for cortical myoclonus have been proposed. These include the presence of giant somatosensory evoked potentials, enhanced long-latency reflexes, electroencephalographic discharges time-locked to individual myoclonic jerks and significant cortico-muscular connectivity. Other features that are assumed to support the cortical origin of myoclonus are short-duration electromyographic bursts, the presence of both positive and negative myoclonus and cranial-caudal progression of the jerks. While these criteria are widely used in clinical practice and research settings, their application can be difficult in practice and, as a result, they are fulfilled only by a minority of patients. In this review we reappraise the evidence that led to the definition of the electrophysiological criteria of cortical myoclonus, highlighting possible methodological incongruencies and misconceptions. We believe that, at present, the diagnostic accuracy of cortical myoclonus can be increased only by combining observations from multiple tests, according to their pathophysiological rationale; nevertheless, larger studies are needed to standardise the methods, to resolve methodological issues, to establish the diagnostic criteria sensitivity and specificity and to develop further methods that might be useful to clarify the pathophysiology of myoclonus.
Topics: Humans; Myoclonus; Evoked Potentials, Somatosensory; Electroencephalography; Reflex; Neurophysiology; Electromyography
PubMed: 37948946
DOI: 10.1016/j.clinph.2023.10.007 -
Tremor and Other Hyperkinetic Movements... 2020Telemedicine is the use of electronic communication technology to facilitate healthcare between distant providers and patients. In addition to synchronous video... (Review)
Review
Telemedicine is the use of electronic communication technology to facilitate healthcare between distant providers and patients. In addition to synchronous video conferencing, asynchronous video transfer has been used to support care for neurology patients. There is a growing literature on using telemedicine in movement disorders, with the most common focus on Parkinson's disease. There is accumulating evidence for videoconferencing to diagnose and treat patients with hyperkinetic movement disorders and to support providers in remote underserviced areas. Cognitive testing has been shown to be feasible remotely. Genetic counseling and other counseling-based therapeutic interventions have also successfully performed in hyperkinetic movement disorders. We use a problem-based approach to review the current evidence for the use of telemedicine in various hyperkinetic movement disorders. This Viewpoint attempts to identify possible telemedicine solutions as well as discussing unmet needs and future directions.
Topics: Dystonic Disorders; Genetic Counseling; Humans; Huntington Disease; Hyperkinesis; Medically Underserved Area; Movement Disorders; Myoclonus; Neuropsychological Tests; Parkinson Disease; Remote Consultation; Telemedicine; Tic Disorders; Tremor; Videoconferencing
PubMed: 32195039
DOI: 10.7916/tohm.v0.698 -
Neurology Aug 2020To report 3 patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who developed generalized myoclonus.
OBJECTIVE
To report 3 patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who developed generalized myoclonus.
METHODS
Patient data were obtained from medical records from the University Hospital "12 de Octubre," Madrid, Spain.
RESULTS
Three patients (2 men and 1 woman, aged 63-88 years) presented with mild hypersomnia and generalized myoclonus following the onset of the so-called inflammatory phase of coronavirus disease 2019 (COVID-19). All of them had presented previously with anosmia. Myoclonus was generalized with both positive and negative jerks, predominantly involving the facial, trapezius, sternocleidomastoid, and upper extremities muscles. These myoclonic jerks occurred spontaneously and were extremely sensitive to multisensory stimuli (auditive and tactile) or voluntary movements, with an exaggerated startle response. Other causes of myoclonus were ruled out, and none of the patients had undergone respiratory arrest or significant prolonged hypoxia. All of them improved, at least partially, with immunotherapy.
CONCLUSIONS
Our 3 cases highlight the occurrence of myoclonus during the COVID-19 pandemic as a post- or para-infectious immune-mediated disorder. However, we cannot rule out that SARS-CoV-2 may spread transneuronally to first- and second-order structures connected with the olfactory bulb. Further investigation is required to clarify the full clinical spectrum of neurologic symptoms and optimal treatment.
Topics: Aged; Aged, 80 and over; Betacoronavirus; COVID-19; Coronavirus Infections; Female; Glucocorticoids; Humans; Male; Methylprednisolone; Middle Aged; Myoclonus; Pandemics; Pneumonia, Viral; SARS-CoV-2
PubMed: 32439821
DOI: 10.1212/WNL.0000000000009829 -
Tremor and Other Hyperkinetic Movements... 2023Functional movement disorders (FMD) are a diagnostic and therapeutic challenge, both to the neurologist and psychiatrists. The phenomenology is varied and can present as... (Review)
Review
BACKGROUND
Functional movement disorders (FMD) are a diagnostic and therapeutic challenge, both to the neurologist and psychiatrists. The phenomenology is varied and can present as tremors, dystonia, jerks/myoclonus, gait disorder, other abnormal movements or a combination. There has been an increase in the use of electrophysiological studies that are an important tool in the evaluation of FMDs.
METHODS
We searched the database platforms of MEDLINE, Google scholar, Web of Sciences, Scopus using the Medical Subject Heading terms (MeSH) for all the articles from 1st January 1970 till November 2022. A total of 658 articles were obtained by the search mechanism. A total of 79 relevant articles were reviewed thoroughly, of which 26 articles that had electrophysiological data were included in the present review.
RESULTS
Variability, distractibility and entertainability can be demonstrated in functional tremors by using multichannel surface electromyography. Voluntary ballistic movements tend to decrease the tremor, while loading the tremulous limb with weight causes the tremor amplitude to increase in functional tremor. Presence of Bereitschaftspotential demonstrates the functional nature of palatal tremor and myoclonus. Co-contraction testing may be helpful in differentiating functional from organic dystonia. The R2 blink reflex recovery cycle has been found to be abnormally enhanced in organic blepharospasm, whereas it is normal in presumed functional blepharospasm. Plasticity is found to be abnormally high in organic dystonia and normal in functional dystonia, in addition to enhanced facilitation in patients with organic dystonia.
CONCLUSIONS
Electrophysiological tests supplement clinical examination and helps in differentiating FMD from organic movement disorders.
Topics: Humans; Tremor; Myoclonus; Dystonia; Blepharospasm; Movement Disorders; Dystonic Disorders; Electrophysiology; Conversion Disorder
PubMed: 38162980
DOI: 10.5334/tohm.793 -
Cells Jun 2023Familial adult myoclonus Epilepsy (FAME) is a non-coding repeat expansion disorder that has been reported under different acronyms and initially linked to four main... (Review)
Review
Familial adult myoclonus Epilepsy (FAME) is a non-coding repeat expansion disorder that has been reported under different acronyms and initially linked to four main loci: FAME1 (8q23.3-q24.1), FAME 2 (2p11.1-q12.1), FAME3 (5p15.31-p15.1), and FAME4 (3q26.32-3q28). To date, it is known that the genetic mechanism underlying FAME consists of the expansion of similar non-coding pentanucleotide repeats, TTTCA and TTTTA, in different genes. FAME is characterized by cortical tremor and myoclonus usually manifesting within the second decade of life, and infrequent seizures by the third or fourth decade. Cortical tremor is the core feature of FAME and is considered part of a spectrum of cortical myoclonus. Neurophysiological investigations as jerk-locked back averaging (JLBA) and corticomuscular coherence analysis, giant somatosensory evoked potentials (SEPs), and the presence of long-latency reflex I (or C reflex) at rest support cortical tremor as the result of the sensorimotor cortex hyperexcitability. Furthermore, the application of transcranial magnetic stimulation (TMS) protocols in FAME patients has recently shown that inhibitory circuits are also altered within the primary somatosensory cortex and the concomitant involvement of subcortical networks. Moreover, neuroimaging studies and postmortem autoptic studies indicate cerebellar alterations and abnormal functional connectivity between the cerebellum and cerebrum in FAME. Accordingly, the pathophysiological mechanism underlying FAME has been hypothesized to reside in decreased sensorimotor cortical inhibition through dysfunction of the cerebellar-thalamic-cortical loop, secondary to primary cerebellar pathology. In this context, the non-coding pentameric expansions have been proposed to cause cerebellar damage through an RNA-mediated toxicity mechanism. The elucidation of the underlying pathological mechanisms of FAME paves the way to novel therapeutic possibilities, such as RNA-targeting treatments, possibly applicable to other neurodegenerative non-coding disorders.
Topics: Humans; Adult; Myoclonus; Tremor; Epilepsies, Myoclonic; Reflex; Neurodegenerative Diseases
PubMed: 37371086
DOI: 10.3390/cells12121617 -
Epilepsy Research Jul 2023Epilepsy with eyelid myoclonia (EEM) is a generalized epilepsy syndrome with childhood-onset and 2:1 female predominance that consists of: 1. eyelid myoclonia with or... (Review)
Review
Epilepsy with eyelid myoclonia (EEM) is a generalized epilepsy syndrome with childhood-onset and 2:1 female predominance that consists of: 1. eyelid myoclonia with or without absence seizures, 2. eye closure induced seizures or EEG paroxysms, 3. clinical or EEG photosensitivity. While eyelid myoclonia is the disease hallmark, other seizure types, including absence seizures and generalized tonic-clonic seizures, may be present. It is thought to have a genetic etiology, and around one-third of patients may have a positive family history of epilepsy. Recently, specific genetic mutations have been recognized in a minority patients, including in SYNGAP1, NEXMIF, RORB, and CHD2 genes. There are no randomized controlled trials in EEM, and the management literature is largely restricted to small retrospective studies. Broad-spectrum antiseizure medications such as valproate, levetiracetam, lamotrigine, and benzodiazepines are typically used. Seizures typically persist into adulthood, and drug-resistant epilepsy is reported in over 50%.
Topics: Humans; Female; Child; Male; Retrospective Studies; Anticonvulsants; Epilepsy, Generalized; Seizures; Myoclonus; Epilepsy, Absence; Eyelids; Electroencephalography
PubMed: 37121024
DOI: 10.1016/j.eplepsyres.2023.107147 -
Ugeskrift For Laeger Sep 2018Objective tinnitus is a known but rare otologic symptom. This is a case report about a six-year-old boy, who was referred to a hearing clinic for further investigation...
Objective tinnitus is a known but rare otologic symptom. This is a case report about a six-year-old boy, who was referred to a hearing clinic for further investigation of an audible clicking sound. He experienced clicking sounds, and his parents were able to hear the sounds when listening nearby. This objective tinnitus is caused by myoclonus of either the m. tensor tympani or the m. stapedius. We discuss methods to evaluate objective tinnitus including the clinical use of a stethoscope and also the possibility of using impedance measuring in patients with objective tinnitus.
Topics: Child; Humans; Male; Myoclonus; Sound; Stethoscopes; Tinnitus
PubMed: 30259831
DOI: No ID Found -
Tremor and Other Hyperkinetic Movements... 2016Myoclonus may occur after hypoxia. In 1963, Lance and Adams described persistent myoclonus with other features after hypoxia. However, myoclonus occurring immediately... (Review)
Review
BACKGROUND
Myoclonus may occur after hypoxia. In 1963, Lance and Adams described persistent myoclonus with other features after hypoxia. However, myoclonus occurring immediately after hypoxia may demonstrate different syndromic features from classic Lance-Adams syndrome (LAS). The aim of this review is to provide up-to-date information about the spectrum of myoclonus occurring after hypoxia with emphasis on neurophysiological features.
METHODS
A literature search was performed on PubMed database from 1960 to 2015. The following search terms were used: "myoclonus," "post anoxic myoclonus," "post hypoxic myoclonus," and "Lance Adams syndrome." The articles describing clinical features, neurophysiology, management, and prognosis of post-hypoxic myoclonus cases were included for review.
RESULTS
Several reports in the literature were separated clinically into "acute post-hypoxic myoclonus," which occurred within hours of severe hypoxia, and "chronic post-hypoxic myoclonus," which occurred with some recovery of mental status as the LAS. Acute post-hypoxic myoclonus was generalized in the setting of coma. Chronic post-hypoxic myoclonus presented as multifocal cortical action myoclonus that was significantly disabling. There was overlap of neurophysiological findings for these two syndromes but also different features. Treatment options for these two distinct clinical-neurophysiologic post-hypoxic myoclonus syndromes were approached differently.
DISCUSSION
The review of clinical and neurophysiological findings suggests that myoclonus after hypoxia manifests in one or a combination of distinct syndromes: acute and/or chronic myoclonus. The mechanism of post-hypoxic myoclonus may arise either from cortical and/or subcortical structures. More research is needed to clarify mechanisms and treatment of post-hypoxic myoclonus.
PubMed: 27708982
DOI: 10.7916/D89C6XM4 -
Movement Disorders Clinical Practice Jul 2022Myoclonus is defined as a brief and jerky shock-like involuntary movement caused by abrupt muscle contraction or sudden cessation of ongoing muscular activity. Myoclonus...
Myoclonus is defined as a brief and jerky shock-like involuntary movement caused by abrupt muscle contraction or sudden cessation of ongoing muscular activity. Myoclonus can be generated by abnormal activity in different parts of the nervous system, both peripheral and central, including cortical and subcortical structures. According to the presumed neural generator, myoclonus is classified as cortical, subcortical (including myoclonus-dystonia and brainstem/reticular myoclonus), spinal (including segmental spinal and propriospinal myoclonus), and peripheral. The identification of myoclonus subtypes, and therefore its potential source, is clinically important because it can guide diagnosis and treatment. In this video lecture (Video), we reviewed how to determine myoclonus origin. We first reviewed the clinical features typical of each myoclonus subtype. We, then, explored the electrophysiological techniques that can aid in the differential diagnosis of myoclonus, based on its origin. In conclusion, we provided a clinical and electrophysiological overview on how to find clues about neural generators of myoclonus.
PubMed: 35844279
DOI: 10.1002/mdc3.13472