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Neurology Feb 2018To determine the contribution of electrophysiologic testing in the diagnosis and anatomical classification of myoclonus.
OBJECTIVE
To determine the contribution of electrophysiologic testing in the diagnosis and anatomical classification of myoclonus.
METHODS
Participants with a clinical diagnosis of myoclonus were prospectively recruited, each undergoing a videotaped clinical examination and battery of electrophysiologic tests. The diagnosis of myoclonus and its subtype was reviewed after 6 months in the context of the electrophysiologic findings and specialist review of the videotaped clinical examination.
RESULTS
Seventy-two patients with myoclonus were recruited. Initial clinical anatomical classification included 25 patients with cortical myoclonus, 7 with subcortical myoclonus, 2 with spinal myoclonus, and 15 with functional myoclonic jerks. In 23 cases, clinical anatomical classification was not possible because of the complexity of the movement disorder. Electrophysiologic testing was completed in 66, with agreement of myoclonus in 60 (91%) and its subtype in 28 (47%) cases. Subsequent clinical review by a movement disorder specialist agreed with the electrophysiologic findings in 52 of 60; in the remaining 8, electrophysiologic testing was inconclusive.
CONCLUSIONS
Electrophysiologic testing is an important additional tool in the diagnosis and anatomical classification of myoclonus, also aiding in decision-making regarding therapeutic management. Further development of testing criteria is necessary to optimize its use in clinical practice.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Electrodiagnosis; Female; Follow-Up Studies; Humans; Male; Middle Aged; Myoclonus; Neurologic Examination; Prospective Studies; Severity of Illness Index; Video Recording; Young Adult
PubMed: 29352095
DOI: 10.1212/WNL.0000000000004996 -
Neurobiology of Disease Jun 2024Progressive myoclonus ataxia (PMA) is a rare clinical syndrome characterized by the presence of progressive myoclonus and ataxia, and can be accompanied by mild...
Progressive myoclonus ataxia (PMA) is a rare clinical syndrome characterized by the presence of progressive myoclonus and ataxia, and can be accompanied by mild cognitive impairment and infrequent epileptic seizures. This is the first study to describe the natural history of PMA and identify clinical, electrophysiological, and genetic features explaining the variability in disease progression. A Dutch cohort of consecutive patients meeting the criteria of the refined definition of PMA was included. The current phenotype was assessed during in-person consultation by movement disorders experts, and retrospective data was collected to describe disease presentation and progression, including brain imaging and therapy efficacy. Extensive genetic and electrophysiological tests were performed. The presence of cortical hyperexcitability was determined, by either the identification of a cortical correlate of myoclonic jerks with simultaneous electromyography-electroencephalography or a giant somatosensory evoked potential. We included 34 patients with PMA with a median disease duration of 15 years and a clear progressive course in most patients (76%). A molecular etiology was identified in 82% patients: ATM, CAMTA1, DHDDS, EBF3, GOSR2, ITPR1, KCNC3, NUS1, POLR1A, PRKCG, SEMA6B, SPTBN2, TPP1, ZMYND11, and a 12p13.32 deletion. The natural history is a rather homogenous onset of ataxia in the first two years of life followed by myoclonus in the first 5 years of life. Main accompanying neurological dysfunctions included cognitive impairment (62%), epilepsy (38%), autism spectrum disorder (27%), and behavioral problems (18%). Disease progression showed large variability ranging from an epilepsy free PMA phenotype (62%) to evolution towards a progressive myoclonus epilepsy (PME) phenotype (18%): the existence of a PMA-PME spectrum. Cortical hyperexcitability could be tested in 17 patients, and was present in 11 patients and supported cortical myoclonus. Interestingly, post-hoc analysis showed that an absence of cortical hyperexcitability, suggesting non-cortical myoclonus, was associated with the PMA-end of the spectrum with no epilepsy and milder myoclonus, independent of disease duration. An association between the underlying genetic defects and progression on the PMA-PME spectrum was observed. By describing the natural history of the largest cohort of published patients with PMA so far, we see a homogeneous onset with variable disease progression, in which phenotypic evolution to PME occurs in the minority. Genetic and electrophysiological features may be of prognostic value, especially the determination of cortical hyperexcitability. Furthermore, the identification of cortical and non-cortical myoclonus in PMA helps us gain insight in the underlying pathophysiology of myoclonus.
PubMed: 38844245
DOI: 10.1016/j.nbd.2024.106555 -
Tremor and Other Hyperkinetic Movements... 2023Creutzfeldt-Jakob disease (CJD) is a rare neuro degenerative disease that is mainly characterized by rapidly progressive dementia along with a varying combination of...
BACKGROUND
Creutzfeldt-Jakob disease (CJD) is a rare neuro degenerative disease that is mainly characterized by rapidly progressive dementia along with a varying combination of myoclonus, visual, cerebellar, pyramidal/extrapyramidal and akinetic mutism. Several movement disorders phenomenologies can occurs either at onset, as presenting symptom or during the course of illness. Present study aims to characterize the clinical, radiological features and the outcome of patients with CJD with movement disorders as the forthcoming manifestation.
METHODS
Chart review of patients with CJD with movement disorders. Demographic, clinical and radiological details of the patients were reviewed.
RESULTS
25 patients (13 males) of sCJD with median age at presentation of 58 years and median duration of illness of 5 months were included in the study. According to revised CDC diagnostic criteria 1 patient was classified as definite sCJD, 20 as probable and 2 as possible CJD. Myoclonus, ataxia and parkinsonism were the most common movement disorder and chorea was the least common. Magnetic resonance imaging of brain was performed in all and basal ganglia abnormality and cortical ribboning was seen in more than two-third of cases. Electroencephalographic abnormality was noted in 21 patients with triphasic waves and periodic sharp waves seen in 7 and 6 patients respectively. Cerebrospinal fluid 14-3-3 assay was abnormal in 2 out of 4 patients. Atypical presentations were noted in the form of ataxic presentation, CBS like presentation and choreiform presentation.
CONCLUSION
Myoclonus, ataxia and parkinsonism are the most frequent movement disorders phenomenology observed in patients with sCJD.
Topics: Male; Humans; Creutzfeldt-Jakob Syndrome; Myoclonus; Ataxia; Parkinsonian Disorders
PubMed: 37152622
DOI: 10.5334/tohm.753 -
Epilepsia Mar 2024Epilepsy with eyelid myoclonia (EEM) spectrum is a generalized form of epilepsy characterized by eyelid myoclonia with or without absences, eye closure-induced seizures...
OBJECTIVE
Epilepsy with eyelid myoclonia (EEM) spectrum is a generalized form of epilepsy characterized by eyelid myoclonia with or without absences, eye closure-induced seizures with electroencephalographic paroxysms, and photosensitivity. Based on the specific clinical features, age at onset, and familial occurrence, a genetic cause has been postulated. Pathogenic variants in CHD2, SYNGAP1, NEXMIF, RORB, and GABRA1 have been reported in individuals with photosensitivity and eyelid myoclonia, but whether other genes are also involved, or a single gene is uniquely linked with EEM, or its subtypes, is not yet known. We aimed to dissect the genetic etiology of EEM.
METHODS
We studied a cohort of 105 individuals by using whole exome sequencing. Individuals were divided into two groups: EEM- (isolated EEM) and EEM+ (EEM accompanied by intellectual disability [ID] or any other neurodevelopmental/psychiatric disorder).
RESULTS
We identified nine variants classified as pathogenic/likely pathogenic in the entire cohort (8.57%); among these, eight (five in CHD2, one in NEXMIF, one in SYNGAP1, and one in TRIM8) were found in the EEM+ subcohort (28.57%). Only one variant (IFIH1) was found in the EEM- subcohort (1.29%); however, because the phenotype of the proband did not fit with published data, additional evidence is needed before considering IFIH1 variants and EEM- an established association. Burden analysis did not identify any single burdened gene or gene set.
SIGNIFICANCE
Our results suggest that for EEM, as for many other epilepsies, the identification of a genetic cause is more likely with comorbid ID and/or other neurodevelopmental disorders. Pathogenic variants were mostly found in CHD2, and the association of CHD2 with EEM+ can now be considered a reasonable gene-disease association. We provide further evidence to strengthen the association of EEM+ with NEXMIF and SYNGAP1. Possible new associations between EEM+ and TRIM8, and EEM- and IFIH1, are also reported. Although we provide robust evidence for gene variants associated with EEM+, the core genetic etiology of EEM- remains to be elucidated.
Topics: Humans; Exome Sequencing; Interferon-Induced Helicase, IFIH1; Myoclonus; Epilepsy, Reflex; Electroencephalography; Eyelids; Carrier Proteins; Nerve Tissue Proteins; Epilepsy, Generalized
PubMed: 38088023
DOI: 10.1111/epi.17859 -
Clinical Neurophysiology Practice 2020The back-average technique is very useful to study the relation between the activity in the cortex and the muscles. It has two main clinical applications,...
OBJECTIVE
The back-average technique is very useful to study the relation between the activity in the cortex and the muscles. It has two main clinical applications, Bereitschaftspotential (BP) recording and myoclonus studies. The BP is a slow wave negativity originating in the supplementary motor cortex and premotor cortex that precedes voluntary movements. This wave also precedes involuntary movements in functional movement disorders (FMD), and it can be used as a helpful diagnostic tool. For the myoclonus studies, the back-average technique is very important to help localizing the source of the myoclonus. The hardware needed to do BP or myoclonus studies is standard and available in any electrophysiology lab, but there are not many software solutions to do the analysis. In this article together with describing the methodology that we use for recording clinical BPs and myoclonus, we present BacAv, an online free application that we developed for the purpose of doing back-average analysis.
METHODS
BacAv was developed in "R" language using Rstudio, a free integrated development environment. The recommended parameters for the data acquisition for BP recording and myoclonus studies are given in this section.
RESULTS
The platform was successfully developed, is able to read txt files, look for muscle bursts, segment the data, and plot the average. The parameters of the algorithm that look for the muscle bursts can be adapted according to the characteristics of the dataset.
CONCLUSION
We have developed software for clinicians who do not have sophisticated equipment to do back-averaging.
SIGNIFICANCE
This tool will make this useful analysis method more available in a clinical environment.
PubMed: 32095660
DOI: 10.1016/j.cnp.2019.12.001 -
Neurology India 2022
Topics: Humans; Myoclonus; Hypoxia, Brain
PubMed: 36352643
DOI: 10.4103/0028-3886.359171 -
BMJ Case Reports Jul 2021Postinfectious generalised myoclonus has been reported after many viral and bacterial infections in the past. Recently, some case reports have described it in the...
Postinfectious generalised myoclonus has been reported after many viral and bacterial infections in the past. Recently, some case reports have described it in the context of COVID-19 infection. Most patients described in these case reports are either critically ill and intubated or have concurrent respiratory symptoms. Herein, we present a case of a 79-year-old man, who was recovering from a recent COVID-19 infection, presented with isolated generalised myoclonus. The patient was treated with levetiracetam, a short course (10 days) of dexamethasone, and required extensive rehabilitation. Outpatient follow-up at 2 months suggested complete resolution of symptoms and levetiracetam was subsequently discontinued. This case highlights that generalised myoclonus can occur as a delayed complication of COVID-19 infection.
Topics: Aged; COVID-19; Humans; Levetiracetam; Male; Myoclonus; SARS-CoV-2
PubMed: 34301706
DOI: 10.1136/bcr-2021-243780 -
Movement Disorders : Official Journal... Aug 2018The clinical demarcation of the syndrome progressive myoclonus ataxia is unclear, leading to a lack of recognition and difficult differentiation from other neurological...
BACKGROUND
The clinical demarcation of the syndrome progressive myoclonus ataxia is unclear, leading to a lack of recognition and difficult differentiation from other neurological syndromes.
OBJECTIVES
The objective of this study was to apply a refined definition of progressive myoclonus ataxia and describe the clinical characteristics in patients with progressive myoclonus ataxia and with isolated cortical myoclonus.
METHODS
A retro- and prospective analysis was performed in our tertiary referral center between 1994 and 2014. Inclusion criteria for progressive myoclonus ataxia patients were the presence of myoclonus and ataxia with or without infrequent (all types, treatment responsive) epileptic seizures. Inclusion criteria for isolated cortical myoclonus was the presence of isolated cortical myoclonus. Clinical and electrophysiological characteristics data were systematically scored.
RESULTS
A total of 14 progressive myoclonus ataxia patients (males, 7; females, 7), median age 14.5 years, and 8 isolated cortical myoclonus patients (males, 2; females, 6), median age 23.5 years, were identified. In 93% of the progressive myoclonus ataxia patients, ataxia started first (median 2 years) followed by myoclonus (4 years) and finally infrequent epilepsy (9.3 years), with a progressive course in 93%. In 64% of the progressive myoclonus ataxia patients, a genetic underlying etiology was identified, including 3 not earlier reported causative progressive myoclonus ataxia genes. In isolated cortical myoclonus patients, myoclonus started at (median) 12 years with progression over time in 63% and a single epileptic seizure in 1 patient. No genetic causes were identified.
CONCLUSION
Using a refined definition, we could create a rather homogenous progressive myoclonus ataxia group. Patients with isolated cortical myoclonus have a different course and do not appear to evolve in progressive myoclonus ataxia. The refined progressive myoclonus ataxia definition is a successful first step toward creating a separate syndrome for both clinical practice and future genetic research. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
Topics: Adolescent; Adult; Cerebellar Ataxia; Child; Cognitive Dysfunction; Cohort Studies; Disease Progression; Electrophysiology; Female; Humans; Male; Myoclonus; Myography; Young Adult
PubMed: 30145808
DOI: 10.1002/mds.27412 -
The Primary Care Companion For CNS... Jun 2022
Topics: Antipsychotic Agents; Dose-Response Relationship, Drug; Humans; Myoclonus; Quetiapine Fumarate
PubMed: 35687883
DOI: 10.4088/PCC.21cr02907 -
Neurological Sciences : Official... Jun 2022
Topics: Diaphragm; Fever; Humans; India; Myoclonus; Scrub Typhus
PubMed: 35306612
DOI: 10.1007/s10072-022-06021-y