Myoclonus improvement after seizures in progressive myoclonic epilepsy type 7: a case report.

BACKGROUND: Progressive Myoclonic Epilepsy (PME) is a group of rare diseases that are difficult to differentiate from one another based on phenotypical characteristics. CASE REPORT: We report a case of PME type 7 due to a pathogenic variant in KCNC1 with myoclonus improvement after epileptic seizures. DISCUSSION: Myoclonus improvement after seizures may be a clue to the diagnosis of Progressive Myoclonic Epilepsy type 7.

Subacute sclerosing panencephalitis presenting as severe depression in an adult.

Subacute sclerosing panencephalitis (SSPE) is a fatal disorder that occurs as a rare complication of childhood measles. Symptoms typically manifest between the ages of 5 and 15. While the incidence of SSPE is declining globally, it is still prevalent in regions where measles remains common and vaccination rates are low due to poverty and lack of health education. Diagnosing SSPE can be challenging, particularly when patients exhibit unusual symptoms. A thorough clinical evaluation, including vaccination history, physical examination, electroencephalogram (EEG) and Cerebrospinal fluid (CSF) analysis, can help in making a diagnosis. We present the case of a young woman in her early 20s who initially experienced depressive symptoms, followed by myoclonus, dementia and visual impairment. The patient was ultimately diagnosed with SSPE based on characteristic EEG findings, neuroimaging results, CSF analysis and elevated serum measles antibody levels.

Frequency of Myoclonus and its Countermeasures in Terminally Ill Patients with Cancer: A Single-Center Retrospective Study.

Myoclonus is a relatively rare involuntary movement that is often observed in palliative care settings and that can cause patient distress. The purpose of this study is to investigate the occurrence of myoclonus and countermeasures against it in terminally ill patients with cancer diagnosed by palliative care specialists at Komaki City Hospital, Japan. We retrospectively reviewed patients with terminal cancer who received palliative care consultations between January 2018 and May 2019 and who were diagnosed with myoclonus by palliative care specialists, using electronic medical records. Patient demographics, time from onset of myoclonus to death, daily opioid use, countermeasures, and outcome of myoclonus were assessed. Of 360 patients examined during this period, 45 (12.5%) were diagnosed with myoclonus. Median age was 71 (range, 43-88) years; median time from onset of myoclonus to death was 8 days (range, 0-56); opioid usage was present in 39 patients (morphine, oxycodone, and fentanyl: n = 6, 21, and 12, respectively); and median oral morphine equivalent at onset of myoclonus was 60 mg (range, 12-336 mg). Myoclonus treatment was administered to 21 patients (opioid dose reduction, opioid switching, and others: n = 14, 3, and 4, respectively). Myoclonus is a common complication in patients with terminal cancer.

Myoclonus and Dystonia as Recurrent Presenting Features in Patients with the SCA21-Associated TMEM240 p.Pro170Leu Variant.

Background: Spinocerebellar ataxia 21 (SCA21) is a rare neurological disorder caused by heterozygous variants in TMEM240. A growing, yet still limited number of reports suggested that hyperkinetic movements should be considered a defining component of the disease. Case Series: We describe two newly identified families harboring the recurrent pathogenic TMEM240 p.Pro170Leu variant. Both index patients and the mother of the first proband developed movement disorders, manifesting as myoclonic dystonia and action-induced dystonia without co-occurring ataxia in one case, and pancerebellar syndrome complicated by action-induced dystonia in the other. We reviewed the literature on TMEM240 variants linked to hyperkinetic disorders, comparing our cases to described phenotypes. Discussion: Adding to prior preliminary observations, our series highlights the relevance of hyperkinetic movements as clinically meaningful features of SCA21. TMEM240 mutation should be included in the differential diagnosis of myoclonic dystonia and ataxia-dystonia syndromes.

COVID 19 and myoclonus, do hemodialysis patients have more risk?

We discuss two recent cases from our hospital in which two patients with ESKD receiving periodical hemodialysis (HD) and SarS-Cov-2 infection suffered movement disorders, being the onset related to the HD sessions in both. First case is a 78 year-old woman who is admitted with generalized myoclonic status epilepticus and second case is a 46 year-old male who starts repeatedly suffering myoclonus during his hemodialysis sessions on day +10 after testing positive (asymptomatic infection). There are two main hypotheses when it comes to myoclonus and CNS disorders in COVID19, post-hypoxic origin and inmunomediated postinfectious origin. We wonder if they could both be interacting in patients with kidney disease, and especially in those who receive hemodialysis, maximizing the risk of suffering this type of disorders.

Flapping Tremor: Unraveling Asterixis-A Narrative Review.

Asterixis is a subtype of negative myoclonus characterized by brief, arrhythmic lapses of sustained posture due to involuntary pauses in muscle contraction. We performed a narrative review to characterize further asterixis regarding nomenclature, historical aspects, etiology, pathophysiology, classification, diagnosis, and treatment. Asterixis has been classically used as a synonym for negative myoclonus across the literature and in previous articles. However, it is important to distinguish asterixis from other subtypes of negative myoclonus, for example, epileptic negative myoclonus, because management could change. Asterixis is not specific to any pathophysiological process, but it is more commonly reported in hepatic encephalopathy, renal and respiratory failure, cerebrovascular diseases, as well as associated with drugs that could potentially lead to hyperammonemia, such as valproic acid, carbamazepine, and phenytoin. Asterixis is usually asymptomatic and not spontaneously reported by patients. This highlights the importance of actively searching for this sign in the physical exam of encephalopathic patients because it could indicate an underlying toxic or metabolic cause. Asterixis is usually reversible upon treatment of the underlying cause.

Tensor Tympani and Stapedial Tendon Reconstruction for Postoperative Hyperacusis after Tendon Lysis for Middle Ear Myoclonus.

OBJECTIVE: To present a method for repair of the stapedial and tensor tympani tendons in a patient with hyperacusis after a tendon lysis procedure. PATIENTS: A 71-year-old professional musician who presented to clinic with debilitating hyperacusis following a tensor tympani and stapedial tendon lysis procedure to treat middle ear myoclonus. INTERVENTIONS: A novel procedure for reapproximation of the tensor tympani and stapedial tendons into their native insertion points using periosteal grafts and nitinol wire. MAIN OUTCOMES MEASURES: Stapedial reflex measurements, uncomfortable loudness level, and subjective patient experience. RESULTS: Postoperatively, the patient had objective improvement in hyperacusis with return of acoustic reflexes in the affected ear and durable improvements in their frequency-specific uncomfortable loudness levels. CONCLUSIONS: This case describes the debilitating complication of hyperacusis following tendon lysis and highlights the importance of maximizing behavioral and medical measures prior to undergoing surgical intervention for middle ear myoclonus.

Spinal Segmental Myoclonus in Primary Progressive Multiple Sclerosis.

Background: A wide variety of associated movement disorders has been described in multiple sclerosis. Phenomenology Shown: A 57-year-old woman with primary progressive multiple sclerosis developed spinal segmental myoclonus associated with focal myelitis. Educational Value: Movement disorders in multiple sclerosis are phenomenologically diverse and have varied pathophysiological mechanisms, making it essential to identify them to initiate appropriate treatment.

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.

Myoclonus: Differential diagnosis and current management.

Myoclonus classically presents as a brief (10-50 ms duration), non-rhythmic jerk movement. The etiology could vary considerably ranging from self-limited to chronic or even progressive disorders, the latter falling into encephalopathic pictures that need a prompt diagnosis. Beyond the etiological classification, others evaluate myoclonus' body distribution (i.e., clinical classification) or the location of the generator (i.e., neurophysiological classification); particularly, knowing the anatomical source of myoclonus gives inputs on the observable clinical patterns, such as EMG bursts duration or EEG correlate, and guides the therapeutic choices. Among all the chronic disorders, myoclonus often presents itself as a manifestation of epilepsy. In this context, myoclonus has many facets. Myoclonus occurs as one, or the only, seizure manifestation while it can also present as a peculiar type of movement disorder; moreover, its electroclinical features within specific genetically determined epileptic syndromes have seldom been investigated. In this review, following a meeting of recognized experts, we provide an up-to-date overview of the neurophysiology and nosology surrounding myoclonus. Through the dedicated exploration of epileptic syndromes, coupled with pragmatic guidance, we aim to furnish clinicians and researchers alike with practical advice for heightened diagnostic management and refined treatment strategies. PLAIN LANGUAGE SUMMARY: In this work, we described myoclonus, a movement characterized by brief, shock-like jerks. Myoclonus could be present in different diseases and its correct diagnosis helps treatment.

Epilepsy with eyelid myoclonia (Jeavons syndrome): Generalized, focal, or combined generalized and focal epilepsy syndrome?

Epilepsy with eyelid myoclonia (EM) or Jeavons syndrome (JS) is an epileptic syndrome related to the spectrum of genetic generalized epilepsies (GGE). We report two untreated children on which EEGs were performed several hours after a generalized tonic-clonic seizure (GTCS). These showed a unilateral, nearly continuous posterior slowing. This slow-wave activity was associated with contralateral epileptiform activity in one case, while in the second case, it was associated with an ipsilateral activity. However, in the latter child, a few months later an independent focus on the contralateral side was observed. A diagnosis of focal occipital lobe epilepsy was proposed in both cases, and one child underwent a left occipital lobectomy at 3.5 years of age. Despite surgery, absences with EM persisted in this child, and a marked photosensitivity to photic stimulation was observed two years later. The focal slow wave activity of one occipital lobe several hours after a GTCS in these two subjects was in favor of a focal onset preceding the generalization. The EEG evidence for independent left and right posterior focus in these two cases, the persistence of EM, and the development of a marked photosensitivity to photic stimulation in the child who underwent an occipital lobectomy, allow us to suggest that JS is associated with a network of bi-occipital hyperexcitability that rapidly engages bilaterally to produce generalized seizures.

Progressive Myoclonus Epilepsy: A Scoping Review of Diagnostic, Phenotypic and Therapeutic Advances.

The progressive myoclonus epilepsies (PME) are a diverse group of disorders that feature both myoclonus and seizures that worsen gradually over a variable timeframe. While each of the disorders is individually rare, they collectively make up a non-trivial portion of the complex epilepsy and myoclonus cases that are seen in tertiary care centers. The last decade has seen substantial progress in our understanding of the pathophysiology, diagnosis, prognosis, and, in select disorders, therapies of these diseases. In this scoping review, we examine English language publications from the past decade that address diagnostic, phenotypic, and therapeutic advances in all PMEs. We then highlight the major lessons that have been learned and point out avenues for future investigation that seem promising.

DHDDS and NUS1: A Converging Pathway and Common Phenotype.

BACKGROUND: Variants in dehydrodolichol diphosphate synthetase (DHDDS) and nuclear undecaprenyl pyrophosphate synthase 1 (NUS1) cause a neurodevelopmental disorder, classically with prominent epilepsy. Recent reports suggest a complex movement disorder and an overlapping phenotype has been postulated due to their combined role in dolichol synthesis. CASES: We describe three patients with heterozygous variants in DHDDS and five with variants affecting NUS1. They bear a remarkably similar phenotype of a movement disorder dominated by multifocal myoclonus. Diagnostic clues include myoclonus exacerbated by action and facial involvement, and slowly progressive or stable, gait ataxia with disproportionately impaired tandem gait. Myoclonus is confirmed with neurophysiology, including EMG of facial muscles. LITERATURE REVIEW: Ninety-eight reports of heterozygous variants in DHDDS, NUS1 and chromosome 6q22.1 structural alterations spanning NUS1, confirm the convergent phenotype of hypotonia at birth, developmental delay, multifocal myoclonus, ataxia, dystonia and later parkinsonism with or without generalized epilepsy. Other features include periodic exacerbations, stereotypies, anxiety, and dysmorphisms. Although their gene products contribute to dolichol biosynthesis, a key step in N-glycosylation, transferrin isoform profiles are typically normal. Imaging is normal or non-specific. CONCLUSIONS: Recognition of their shared phenotype may expedite diagnosis through chromosomal microarray and by including DHDDS/NUS1 in movement disorder gene panels.