Search

We report ATP1A3-associated rapid-onset dystonia-parkinsonism with an atypical presentation including myoclonus and exaggerated startle in four patients. Their prominence over parkinsonism prompted consideration of a syndromic diagnosis of myoclonus dystonia. ATP1α3 dysfunction in GABAergic neurons could explain these examination findings. The spectrum of ATP1A3-associated movement disorders includes myoclonus-dystonia., Competing Interests: Declaration of competing interest No COI., (Copyright © 2023. Published by Elsevier Ltd.)

Background: Myoclonus-dystonia (MD) is a syndrome characterized by subcortical myoclonus and milder dystonia. The main causative gene is the epsilon sarcoglycan gene (SGCE), but other genes may be involved. Response to medications is variable, with poor tolerability limiting their use., Case Presentation: We present the case of a patient with severe myoclonic jerks and mild dystonia since childhood. At first neurological visit at the age of 46 years old, she presented brief myoclonic jerks predominating in the upper limbs and neck, mild at rest and elicited by action, posture and tactile stimulus. Myoclonus was accompanied by mild neck and right arm dystonia. Neurophysiological tests suggested subcortical origin of myoclonus, brain MRI was unremarkable. Myoclonus-dystonia was diagnosed, and genetic testing identified a novel mutation in SGCE gene (c.907delC) in heterozygosis. Over time she assumed a large variety of anti-epileptics without beneficial effect on myoclonus and low tolerability. Add-on treatment with Perampanel was started, with a beneficial effect. No adverse events were reported. Perampanel is the first selective non-competitive AMPA receptor antagonist approved in add-on for focal and generalized tonic-clonic seizures. To our knowledge, this is the first trial of Perampanel in MD., Conclusions: We presented the case of a patient with MD due to SGCE mutation who was treated with Perampanel with beneficial effects. We propose Perampanel as a novel treatment for myoclonus in MD., (© 2023. Fondazione Società Italiana di Neurologia.)

Abnormal involuntary movement (AIM) are usually classified into hypokinesia and hyperkinesia group. Hyperkinesia-AIM includes myoclonus, chorea, ballism, dystonia, athetosis, and more. Of these, dystonia, myoclonus, and chorea are frequent movement disorders. From a neurophysiological point of view, the mechanism of motor control by the basal ganglia is thought to consist of three pathways: hyperdirect, direct, and indirect. Hyperkinetic-AIMs are likely caused by the dysfunction of any of these three pathways, leading to malfunction in either presurround inhibition, initiation of motor performance, or postsurround inhibition. These dysfunctions are assumed to stem from regions, such as the cerebral cortex, white matter, basal ganglia, brainstem, and cerebellum. Drug therapies that consider the pathogenesis mechanism are desirable. Here, we presented an overview of treatment methods for hyperkinetic-AIMs.

Background: Hypertrophic olivary degeneration (HOD) is a rare condition caused by lesions within the dentato-rubro-olivary pathway, resulting in ocular nystagmus and palatal myoclonus (oculopalatal tremor) but not usually dystonia. Dystonia is an uncommon association, and we present the first reported association of hypertrophic olivary degeneration with bilateral vocal cord dystonia., Case Presentation: A 33 year old male presented initially with acute hydrocephalus on the background of previous ventriculoperitoneal (VP) shunting for previously treated medulloblastoma. After revision of the VP shunt, the patient developed progressive hiccups and stridor leading to respiratory failure requiring intubation. Ocular pendular nystagmus and palatal myoclonus at 3 Hz was observed. Flexible nasendoscopy (FNE) demonstrated bilateral tonic adduction of the vocal folds with 3 Hz coarse supraglottic, pharyngeal and palatal rhythmic myoclonus. MRI imaging demonstrated T2 hyperintensity within the bilateral inferior olivary nuclei consistent with stage 3 radiological HOD., Conclusions: Dystonia is a rarely reported phenomenon in HOD but is not unexpected with the inferior olivary nucleus implicated in dystonic disorders. We report the association of HOD with bilateral vocal cord adductor dystonia, a potentially life threatening condition., (© 2023. The Author(s).)

Abstract: A 9-year-old boy with primary myoclonus dystonia with comorbid severe attention deficit hyperactive disorder (ADHD) also had sleep onset and maintenance insomnia. Polysomnography showed features of non-rapid eye movement parasomnia. Daily bedtime clonidine helped sleep and hyperactivity. ADHD symptoms improved with 40 mg daily lisdexamphetamine mesylate. As the myoclonus and dystonia symptoms progressed, clonazepam was initiated at a dose of 0.5 mg daily at bedtime. It was anticipated that clonazepam would also improve parasomnia. Concomitant with the initiation of clonazepam, he developed a sleep-related eating disorder (SRED) continuing almost throughout the night. The symptoms went away upon stopping clonazepam. This is the first description of clonazepam producing SRED though it is the treatment of choice for this disorder., (© 2018 American Academy of Sleep Medicine.)

Spinocerebellar ataxia 19/22 (SCA19/22) is a rare type of autosomal dominant SCA that was previously described in 11 families. We report the case of a 30-year-old Japanese man presenting with intellectual disability, early onset cerebellar ataxia, myoclonus, and dystonia without a family history. MRI showed cerebellar atrophy, and electroencephalograms showed paroxysmal sharp waves during hyperventilation and photic stimulation. Trio whole-exome sequencing analysis of DNA samples from the patient and his parents revealed a de novo novel missense mutation (c.1150G>A, p.G384S) in KCND3, the causative gene of SCA19/22, substituting for evolutionally conserved glycine. The mutation was predicted to be functionally deleterious by bioinformatic analysis. Although pure cerebellar ataxia is the most common clinical feature in SCA19/22 families, extracerebellar symptoms including intellectual disability and myoclonus are reported in a limited number of families, suggesting a genotype-phenotype correlation for particular mutations. Although autosomal recessive diseases are more common in patients with early onset sporadic cerebellar ataxia, the present study emphasizes that such a possibility of de novo mutation should be considered.

Background: Dystonia with anarthria and/or aphonia is a rare syndromic association. Here we present two cases with slowly progressive, severe generalized dystonia and aphonia, slow horizontal saccades, epilepsy and photic myoclonus., Methods: Detailed clinical data were collected over two decades in the female (index) patient and for nine years in her similarly affected son. Sanger sequencing followed by exome sequencing was performed., Results: Both patients had leg onset generalized dystonia with gradual rostral spread including prominent facial and oro-mandibular involvement. The index patient was anarthric, her son aphonic. Both had saccadic slowing, more marked for the horizontal plane, and subclinical epileptic activity. The index patient also had photic myoclonus and a combined axonal and demyelinating neuropathy. Known genetic causes of similar syndromes were not identified., Conclusion: These cases with caudo-rostrally spreading generalized dystonia with prominent facial and oro-mandibular involvement, severe speech impairment, marked slowing of horizontal saccades, and photic myoclonus likely represent a novel entity., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: Cerebrotendinous xanthomatosis (CTX) is an inherited neurometabolic disorder. The main neurological manifestations of the disease are pyramidal syndrome, ataxia, peripheral neuropathy, cognitive impairment, epilepsy, and psychiatric disturbances. Myoclonic dystonia has been reported on in the setting of various neurometabolic diseases. Anecdotal reports describe movement disorders associated with CTX, but no dystonia with myoclonic events., Methods: We collected clinical, biochemical, electrophysiological, neuroradiological, and genetic data of 6 patients with myoclonus and mild dystonia associated with CTX. From a systematic literature review, we analyzed 31 patients with movement disorders secondary to CTX., Results: Our 6 patients presented distal myoclonus with mild dystonia of the upper limbs. Myoclonus was of subcortical origin, based on neurophysiological recordings, and differed from oromandibular myoclonus previously described in CTX patients., Conclusions: These results expand the phenotype of CTX and suggest that myoclonus and/or dystonia are underdiagnosed. In keeping with our findings, tremors previously observed in CTX patients might actually correspond to myoclonic events. We hypothesize that a dysfunction of the dentate nuclei-basal ganglia pathway may be involved., (Copyright © 2012 Movement Disorder Society.)

Background: Myoclonus-dystonia (M-D) is genetic and clinically heterogeneous. Identification and description of rare M-D syndromes may contribute to gene identification., Results: Here, we describe a new, autosomal dominant M-D syndrome in a 3-generation pedigree showing anticipation. Patients have progressive action-induced multifocal dystonia and generalized myoclonus. A remarkable feature of the syndrome is action myoclonus in the lower extremities triggered by upright posture, causing instability. Electrophysiological characterization shows a 12-Hz peak in the EMG autospectrum and corticomuscular and intermuscular coherences., Conclusions: A new familial M-D syndrome with progressive action myoclonus and dystonia is described., (Copyright © 2011 Movement Disorder Society.)

Myoclonus dystonia (M-D) is a rare genetic movement disorder characterized by a combination of myoclonic jerks and dystonia. It is usually due to mutations in the SGCE gene. We report on a patient with a typical M-D syndrome, but also short stature, microcephaly, and mental retardation. Molecular analysis showed no mutations within the SGCE gene but a microdeletion encompassing the SGCE gene in chromosome region 7q21. Array-CGH analysis showed that the deletion spanned approximately 1.88 Mb. We suggest that M-D plus patients with mental retardation, microcephaly, dysmorphism, or short stature, all frequently associated disorders, should be screened for 7q21 microdeletion. By examining previously published cases of mental retardation associated with pure 7q21 deletions, we identified two distinct regions of respectively 455 and 496 kb that are critical for mental retardation and growth retardation. Among the genes located within these regions, LOC253012, also known as HEPACAM2, is a good candidate for both mental retardation and microcephaly., (Copyright 2010 Wiley-Liss, Inc.)

We describe three genetically confirmed myoclonus dystonia (M-D) patients and one spinocerebellar ataxia type 14 (SCA14) patient, presenting with a combination of trunk tremor, multifocal myoclonus and axial dystonia as predominant clinical features. We suggest that in patients with this M-D phenotype, without a mutation in the DYT11 gene, SCA14 should be considered., (Copyright 2009 Elsevier Ltd. All rights reserved.)

Our knowledge of the clinical, neurophysiological, and genetic aspects of myoclonus-dystonia (M-D) has improved markedly in the recent years. Basic research has provided new insights into the complex dysfunctions involved in the pathogenesis of M-D. On the basis of a comprehensive literature search, this review summarizes current knowledge on M-D, with a focus on recent findings. We also propose modified diagnostic criteria and recommendations for clinical management., (2008 Movement Disorder Society)

Myoclonus-dystonia (M-D) is characterized by early-onset myoclonus and dystonia, and is often due to mutations in the epsilon-sarcoglycan gene (SCGE) at locus 7q21. The pathogenesis of M-D is poorly understood, and in a murine knockout model, dopaminergic hyperactivity has been postulated as a mechanism. We present two unrelated individuals with M-D due to SCGE deletions who displayed a robust and sustained response to levodopa (L-dopa) treatment. In contrast to using dopamine blocking agents suggested by the hyperdopaminergic knockout model, we propose that a trial of L-dopa may be considered in patients with myoclonus-dystonia., ((c) 2008 Movement Disorder Society.)

Myoclonus-dystonia (M-D) due to SGCE mutations is characterized by early onset myoclonic jerks, often associated with dystonia. Penetrance is influenced by parental sex, but other sex effects have not been established. In 42 affected individuals from 11 families with identified mutations, we found that sex was highly associated with age at onset regardless of mutation type; the median age onset for girls was 5 years versus 8 years for boys (P < 0.0097). We found no association between mutation type and phenotype., ((c) 2007 Movement Disorder Society.)

Myoclonus-dystonia (M-D) (MIM 159900) is a rare "dystonia plus" syndrome, characterized by rapid myoclonic jerks, predominantly in the neck and upper limbs, in combination with dystonia. Mutations in the gene epsilon-sarcoglycan (SGCE) are known to be responsible for approximately one-third of cases. We screened 21 probands diagnosed with M-D for large deletions who were mutation negative as determined by PCR-direct sequencing. Multiplex PCR and quantification of PCR products was performed using a modified application of denaturing high performance liquid chromatography (dHPLC). We have identified two novel large multiexonic deletions of SGCE, which were confirmed by amplifying and sequencing the deletion breakpoints. Five other families were found to harbor small mutations identified by direct sequencing. Analysis of the region surrounding the deletions demonstrates that both deletions are the result of nonhomologous recombination with homologous end joining. This is only the second report of intragenic deletions with SGCE and it highlights the need to include exonic copy number variation when performing mutational analysis of SGCE., (2008 Movement Disorder Society)

Idiopathic paroxysmal dyskinesias (PxD) are characterized by attacks of hyperkinetic movement, with no inter-ictal symptoms. We report two cases, one with paroxysmal kinesigenic dyskinesia and another with paroxysmal exercise-induced dystonia, both of whom had myoclonus and dystonia between attacks. This previously unreported association highlights the heterogeneity of paroxysmal movement disorders.

This is a case study of a child who developed roseola infantum first, then varicella, and was later affected by acute cerebellar syndrome, severe truncal ataxia, and myoclonic dystonia. Human herpesvirus 6 (HHV-6) A and B were detected in the cerebrospinal fluid (CSF) and peripheral blood, respectively, upon ataxia onset. The intricacy of this case suggests multifaceted conclusions ranging from the need for a multidirectional approach to neurological diseases, to confirmation of a more pronounced neurotropism of HHV-6A and a possible role of viruses in myoclonic dystonia syndrome, although this last hypothesis should be confirmed by larger studies., (2005 Wiley-Liss, Inc.)

Epilepsy and electroencephalogram (EEG) abnormalities have been considered exclusion criteria for the clinical diagnosis of myoclonus-dystonia (M-D). We report on the second M-D family in which several clinically affected epsilon-sarcoglycan gene (SGCE) mutation carriers have seizures in addition to myoclonus and dystonia, adding to the evidence that epilepsy and EEG abnormalities may form part of the phenotypic spectrum of the condition. A nonsense mutation in exon 3 (289C-->T) of SGCE resulting in the insertion of a premature stop codon (R97X) was detected in affected members of this family., (2004 Movement Disorder Society.)

Myoclonus-dystonia (M-D) is a movement disorder characterized by rapid muscle contractions and sustained twisting and repetitive movements and has recently been associated with mutations in the epsilon-sarcoglycan gene (SGCE). The mode of inheritance is autosomal dominant with reduced penetrance upon maternal transmission, suggesting a putative maternal imprinting mechanism. We present an apparently sporadic M-D case and two patients from an M-D family with seemingly autosomal recessive inheritance. In both families, we detected an SGCE mutation that was inherited from the patients' clinically unaffected fathers in an autosomal dominant fashion. Whereas, in the first family, RNA expression studies revealed expression of only the mutated allele in affected individuals and expression of the normal allele exclusively in unaffected mutation carriers, the affected individual of the second family expressed both alleles. In addition, we identified differentially methylated regions in the promoter region of the SGCE gene as a characteristic feature of imprinted genes. Using a rare polymorphism in the promoter region in a family unaffected with M-D as a marker, we demonstrated methylation of the maternal allele, in keeping with maternal imprinting of the SGCE gene. Loss of imprinting in the patient with M-D who had biallelic expression of the SGCE gene was associated with partial loss of methylation at several CpG dinucleotides.

We present the clinical profile of a group of patients with myoclonus and dystonia sensitive to alcohol and address these cases in the context of essential myoclonus. Six patients from 4 families were selected: 4 men and 2 women with myoclonus affecting predominantly the arms. Active movements of these segments elicited the dystonic and myoclonic movements. A marked improvement with alcohol intake was seen. Laboratory findings including EEG, SSEP, and cranial CT and MRI were normal. Surface EMG recording showed bursts with duration of 30-112 ms in 3 patients. One patient showed a triphasic recording pattern (agonist-antagonist-agonist) of ballistic type. Our findings suggest that the myoclonus-dystonia disorder is present in Brazilian patients.

A 35-year-old female was reported who presented early onset and slowly progressive ataxia and retrocollis which appeared at the age of nine. On admission, neurological examination revealed cerebellar ataxia, dystonia of the neck and the right arm, myoclonus of the neck and the shoulder, slight mental retardation, supranuclear upper gaze palsy, and sensorineural hearing loss. Laboratory examination showed high serum CK activity. Electromyography and muscle biopsy findings suggested slight muscular involvement. CSF level of HVA and 5-HIAA were reduced. MRI demonstrated marked cerebellar atrophy and slight atrophy of the brain stem. To our knowledge, the characteristic combination of the neurological sign in this case has not been reported. This case was compared with EOCA (early onset cerebellar ataxia with retained tendon reflexes) and other juvenile onset cerebellar ataxia and dystonia.

Twenty-eight patients with the clinical diagnosis of probable Alzheimer disease (AD) were followed longitudinally until death. The presence of myoclonus, seizures, and paratonia was monitored as part of this process. At autopsy, 22 of the patients met pathologic criteria for AD and 6 had other degenerative neurologic diseases. Myoclonus was present in 55% of the AD patients and none of the non-AD patients. Seizures were present in 64% of the AD patients, and only 17% of the non-AD patients. Paratonia was found frequently in all patient groups. In most patients, symptoms developed late in the course of their illness. The incidence of myoclonus, seizures, and paratonia in our patients was higher than in most previous studies. The reasons for this finding are discussed.

A patient is described with myoclonic dystonia, a disorder characterized by a combination of dystonia and myoclonic contractions. A very good response to epidural cervical cord electrical stimulation was obtained. The findings in this case indicate that epidural cervical cord electrical stimulation could be a useful therapeutic approach in cases of myoclonic dystonia.