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Annals of Medicine and Surgery (2012) Jun 2023Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like syndrome (MELAS) is a rare neurodegenerative inherited disorder that is characterized by stroke-like...
UNLABELLED
Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like syndrome (MELAS) is a rare neurodegenerative inherited disorder that is characterized by stroke-like episodes, seizures, endocrine, and multiple system involvement. It is important to consider it as a differential diagnosis in a young patient with stroke-like episodes as it is progressive and has multiple complications.
CASE PRESENTATION
A 28-year-old male presented with slurring of speech and drowsiness for 7 h. He was a diagnosed case of type 2 diabetes mellitus, Wolf-Parkinson-White syndrome, and bilateral hearing loss.
CLINICAL FINDINGS AND INVESTIGATIONS
The patient had expressive aphasia with impaired fluency, repetition, and naming. After being discharged, he represented with loss of consciousness and involuntary movements of the whole body. MRI and MRS showed extension of hyperintense lesions to parieto-occipital regions from temporal regions not limited by vascular territories. MELAS was considered, which was confirmed by molecular genetic analysis. Coenzyme Q10 was used for MELAS. Insulin, Linagliptin, and levetiracetam were used for diabetes and seizures. Regular follow-up was advised to the patient.MELAS is an important syndrome to consider in any young patient presenting with unexplained stroke disorders. A high index of suspicion is needed in an appropriate clinical setting to avoid misdiagnosis.
PubMed: 37363571
DOI: 10.1097/MS9.0000000000000712 -
Journal of the Formosan Medical... Oct 2023The mitochondrial DNA m.3243A>G mutation can affect mitochondrial function and lead to a wide phenotypic spectrum, including mitochondrial encephalopathy with lactic...
BACKGROUND
The mitochondrial DNA m.3243A>G mutation can affect mitochondrial function and lead to a wide phenotypic spectrum, including mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome, diabetes mellitus, hearing impairment, cardiac involvement, epilepsy, migraine, myopathy, and cerebellar ataxia. However, m.3243A>G has been rarely reported in patients with cerebellar ataxia as their predominant manifestation. The aim of this study is to investigate the prevalence and clinical features of m.3243A>G in a Taiwanese cohort of cerebellar ataxia with unknown genetic diagnosis.
METHODS
This retrospective cohort study conducted the mutation analysis of m.3243A>G by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) in 232 unrelated Han Chinese patients with genetically-undetermined cerebellar ataxia. The clinical presentation and neuroimaging features of patients with m.3243A>G mutation-related cerebellar ataxia were characterized.
RESULTS
We identified two patients harboring m.3243A>G mutation. These patients have suffered from apparently sporadic and slowly progressive cerebellar ataxia since age 52 and 35 years, respectively. Both patients had diabetes mellitus and/or hearing impairment. The neuroimaging studies revealed generalized brain atrophy with predominantly cerebellar involvement in both individuals and bilateral basal ganglia calcifications in one of the patients.
CONCLUSION
Mitochondrial m.3243A>G mutation accounted for 0.9% (2/232) of genetically-undetermined cerebellar ataxia in the Han Chinese cohort in Taiwan. These findings highlight the importance of investigating m.3243A>G in patients with genetically-undetermined cerebellar ataxia.
Topics: Humans; Retrospective Studies; Cerebellar Ataxia; Mutation; DNA, Mitochondrial; Diabetes Mellitus; Hearing Loss
PubMed: 37311680
DOI: 10.1016/j.jfma.2023.05.031 -
JCI Insight Jul 2023Variants within the high copy number mitochondrial genome (mtDNA) can disrupt organelle function and lead to severe multisystem disease. The wide range of manifestations...
Variants within the high copy number mitochondrial genome (mtDNA) can disrupt organelle function and lead to severe multisystem disease. The wide range of manifestations observed in patients with mitochondrial disease results from varying fractions of abnormal mtDNA molecules in different cells and tissues, a phenomenon termed heteroplasmy. However, the landscape of heteroplasmy across cell types within tissues and its influence on phenotype expression in affected patients remains largely unexplored. Here, we identify nonrandom distribution of a pathogenic mtDNA variant across a complex tissue using single-cell RNA-Seq, mitochondrial single-cell ATAC sequencing, and multimodal single-cell sequencing. We profiled the transcriptome, chromatin accessibility state, and heteroplasmy in cells from the eyes of a patient with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) and from healthy control donors. Utilizing the retina as a model for complex multilineage tissues, we found that the proportion of the pathogenic m.3243A>G allele was neither evenly nor randomly distributed across diverse cell types. All neuroectoderm-derived neural cells exhibited a high percentage of the mutant variant. However, a subset of mesoderm-derived lineage, namely the vasculature of the choroid, was near homoplasmic for the WT allele. Gene expression and chromatin accessibility profiles of cell types with high and low proportions of m.3243A>G implicate mTOR signaling in the cellular response to heteroplasmy. We further found by multimodal single-cell sequencing of retinal pigment epithelial cells that a high proportion of the pathogenic mtDNA variant was associated with transcriptionally and morphologically abnormal cells. Together, these findings show the nonrandom nature of mitochondrial variant partitioning in human mitochondrial disease and underscore its implications for mitochondrial disease pathogenesis and treatment.
Topics: Humans; Heteroplasmy; MELAS Syndrome; Mitochondrial Diseases; DNA, Mitochondrial; Retina; Retinal Diseases; Chromatin
PubMed: 37289546
DOI: 10.1172/jci.insight.165937 -
World Journal of Clinical Cases May 2023Here, we present a unique case of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome, which initially appeared to be...
Late-onset mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes syndrome with mitochondrial DNA 3243A>G mutation masquerading as autoimmune encephalitis: A case report.
BACKGROUND
Here, we present a unique case of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome, which initially appeared to be autoimmune encephalitis and was ultimately confirmed as MELAS with the mitochondrial DNA 3243A>G mutation.
CASE SUMMARY
A 58-year-old female presented with acute-onset speech impediment and auditory hallucinations, symmetrical bitemporal lobe abnormalities, clinical and laboratory findings, and a lack of relevant prodromal history, which suggested diagnosis of autoimmune encephalitis. Further work-up, in conjunction with the patient's medical history, family history, and lactate peak on brain lesions on magnetic resonance imaging, suggested a mitochondrial disorder. Mitochondrial genome analysis revealed the m.3243A>G variant in the gene, which led to a diagnosis of MELAS syndrome.
CONCLUSION
This case underscores the importance of considering MELAS as a potential cause of autoimmune encephalitis even if patients are over 40 years of age, as the symptoms and signs are atypical for MELAS syndrome.
PubMed: 37274040
DOI: 10.12998/wjcc.v11.i14.3275 -
Current Neurology and Neuroscience... Jun 2023Uncommon causes of stroke merit specific attention; when clinicians have less common etiologies of stoke in mind, the diagnosis may come more easily. This is key, as... (Review)
Review
PURPOSE OF REVIEW
Uncommon causes of stroke merit specific attention; when clinicians have less common etiologies of stoke in mind, the diagnosis may come more easily. This is key, as optimal management will in many cases differs significantly from "standard" care.
RECENT FINDINGS
Randomized controlled trials (RCT) on the best medical therapy in the treatment of cervical artery dissection (CeAD) have demonstrated low rates of ischemia with both antiplatelet and vitamin K antagonism. RCT evidence supports the use of anticoagulation with vitamin K antagonism in "high-risk" patients with antiphospholipid antibody syndrome (APLAS), and there is new evidence supporting the utilization of direct oral anticoagulation in malignancy-associated thrombosis. Migraine with aura has been more conclusively linked not only with increased risk of ischemic and hemorrhagic stroke, but also with cardiovascular mortality. Recent literature has surprisingly not provided support the utilization of L-arginine in the treatment of patients with mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS); however, there is evidence at this time that support use of enzyme replacement in patients with Fabry disease. Additional triggers for reversible cerebral vasoconstriction syndrome (RCVS) have been identified, such as capsaicin. Imaging of cerebral blood vessel walls utilizing contrast-enhanced MRA is an emerging modality that may ultimately prove to be very useful in the evaluation of patients with uncommon causes of stroke. A plethora of associations between cerebrovascular disease and COVID-19 have been described. Where pertinent, authors provide additional tips and guidance. Less commonly encountered conditions with updates in diagnosis, and management along with clinical tips are reviewed.
Topics: Humans; COVID-19; Stroke; Migraine Disorders; Anticoagulants; Fibrinolytic Agents; Vitamin K
PubMed: 37247169
DOI: 10.1007/s11910-023-01269-z -
Annals of Clinical and Translational... Jun 2023To explore the clinical characteristics of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) caused by mitochondrial DNA-encoded complex...
OBJECTIVE
To explore the clinical characteristics of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) caused by mitochondrial DNA-encoded complex I subunit (mt-ND) variants.
METHODS
In this retrospective study, the clinical, myopathological and brain MRI features of patients with MELAS caused by mt-ND variants (MELAS-mtND) were collected and compared with those of MELAS patients carrying the m.3243A > G variant (MELAS-A3243G).
RESULT
A total of 18 MELAS-mtND patients (female: 7; median age: 24.5 years) represented 15.9% (n = 113) of all patients with MELAS caused by mtDNA variants in our neuromuscular center from January 2012 to June 2022. In this MELAS-mtND cohort, the two most common variants were m.10191 T > C (4/18, 22.2%) and m.13513 G > A (3/18, 16.7%). The most frequent symptoms were seizures (14/18, 77.8%) and muscle weakness (11/18, 61.1%). Compared with 87 MELAS-A3243G patients, MELAS-mtND patients were significantly more likely to have a variant that was absent in blood cells (40% vs. 1.4%). Furthermore, MELAS-mtND patients had a significantly lower MDC score (7.8 ± 2.7 vs. 9.8 ± 1.9); less hearing loss (27.8% vs. 54.0%), diabetes (11.1% vs. 37.9%), and migraine (33.3% vs. 62.1%); less short stature (males ≤ 165 cm; females ≤ 155 cm; 23.1% vs. 60.8%) and higher body mass index (20.4 ± 2.5 vs. 17.8 ± 2.7). MELAS-mtND patients had significantly more normal muscle pathology (31.3% vs. 4.1%) and fewer RRFs/RBFs (62.5% vs. 91.9%), COX-deficient fibers/blue fibers (25.0% vs. 85.1%) and SSVs (50.0% vs. 81.1%). Moreover, brain MRI evaluated at the first stroke-like episode showed significantly more small cortical lesions in MELAS-mtND patients (66.7% vs. 12.2%).
INTERPRETATION
Our results suggested that MELAS-mtND patients have distinct clinical, myopathological and brain MRI features compared with MELAS-A3243G patients.
Topics: Adult; Female; Humans; Male; Young Adult; Brain; Magnetic Resonance Imaging; MELAS Syndrome; Muscles; Retrospective Studies; Stroke
PubMed: 37221696
DOI: 10.1002/acn3.51787 -
CNS Neuroscience & Therapeutics Sep 2023
Topics: Humans; MELAS Syndrome; Acidosis, Lactic; Diet, Ketogenic; Stroke; Ketone Bodies
PubMed: 37208962
DOI: 10.1111/cns.14274 -
Acta Neurologica Taiwanica Jun 2023During corona virus pandemic, various neurological complications of COVID-19 have been reported. Recent studies demonstrated different pathophysiology for neurological...
BACKGROUND
During corona virus pandemic, various neurological complications of COVID-19 have been reported. Recent studies demonstrated different pathophysiology for neurological manifestations of COVID-19 such as mitochondrial dysfunction and damage to cerebral vasculature. In addition, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a mitochondrial disorder with a variety of neurological symptoms. In this study, we aim to assess a potential predisposition in mitochondrial dysfunction of COVID-19, leading to MELAS presentation.
METHODS
We studied three previously healthy patients with the first presentation of acute stroke-like symptoms, following COVID-19 infection. We analyzed the patients' clinical data and brain magnetic resonance imaging (MRI) lesions that presented to the neurological center of a university-affiliated hospital in Tehran, Iran, from September 2020 to August 2021.
RESULTS
All cases are characterized by a temporoparietal abnormality in imaging studies and electroencephalogram (EEG). Based on electrodiagnostic tests, three patients were diagnosed with myopathy. In two brothers with relatively the same symptoms, one performed muscle biopsy finding myopathic process, and genetic testing confirmed a 3243A>G point mutation in a heteroplasmic state in one of our patients.
CONCLUSION
Although MELAS is not a prevalent condition, the recent increase in the number of these patients in our center might indicate the potential role of COVID-19 in triggering the silent pre- existing mitochondrial dysfunction in these patients.
Topics: Male; Humans; MELAS Syndrome; COVID-19; Iran; Acidosis, Lactic; Stroke; Nervous System Diseases; Mitochondria
PubMed: 37198511
DOI: No ID Found -
Medicine May 2023Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is the most common subtype of mitochondrial encephalopathy. In the past, it was believed...
RATIONALE
Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is the most common subtype of mitochondrial encephalopathy. In the past, it was believed that most hereditary white matter lesions were lysosome storage disorders or peroxisome diseases. However, in recent years, white matter lesions have been increasingly regarded as a common feature of patients with mitochondrial diseases. In addition to stroke-like lesions, about half of the patients with MELAS reported white matter lesions in the brain.
PATIENT CONCERNS
Herein, we provide a case of A 48-year-old female who presented with episodic loss of consciousness with twitching of extremities. Previous medical history revealed 10 years of history of epilepsy, 10 years of history of diabetes, a history of hearing loss, and unknown etiology. Ancillary findings included brain magnetic fluid-attenuated inversion recovery showed symmetrical lesions in the bilateral parietal lobe with high signal intensity at the edge, and high signal intensity in the bilateral occipital lobe, paraventricular white matter, corona radiata, and the center of semiovale.
DIAGNOSES
Mitochondrial deoxyribonucleic acid gene sequencing returned A3243G point mutation and it supports the diagnosis of intracranial hypertension.
INTERVENTIONS
Considered the diagnosis of symptomatic epilepsy, the patient was treated with mechanical ventilation, midazolam, and levetiracetam, and the limb twitching symptoms were controlled. The patient was comatose, chronically bedridden, with gastrointestinal dysfunction, and was treated prophylactically with antibiotics against infection, parenteral nutrition, and other supportive measures. B vitamins, vitamin C, vitamin E, coenzyme Q10, and idebenone were given, and mechanical ventilation and midazolam were stopped after 8 days. He was discharged from the hospital on 30 days and continued symptomatic treatment with B-vitamins, vitamin C, vitamin E, coenzyme Q10, and idebenone, and antiepileptic treatment with levetiracetam, with outpatient follow-up.
OUTCOMES
No further seizures were recorded and the patient recovered well.
LESSONS
MELAS syndrome without stroke-like episodes of diffuse posterior cerebral white matter lesions is rare in clinical practice, and the possibility of MELAS syndrome should be considered in symmetric posterior cerebral white matter lesions.
Topics: Male; Female; Humans; Middle Aged; Acidosis, Lactic; MELAS Syndrome; Levetiracetam; Midazolam; Stroke; Ascorbic Acid; Vitamins; Leukoencephalopathies; Vitamin E
PubMed: 37144988
DOI: 10.1097/MD.0000000000033725 -
American Journal of Ophthalmology Case... Jun 2023We present a unique case of foveomacular vitelliform lesions in a patient with metabolic encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS).
PURPOSE
We present a unique case of foveomacular vitelliform lesions in a patient with metabolic encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS).
OBSERVATIONS
After performing large panel next generation sequencing genetic testing, there was no likely alternative genetic etiology for vitelliform maculopathy in this patient.
CONCLUSIONS AND IMPORTANCE
We present a rare case of a visually asymptomatic pediatric patient with MELAS and vitelliform maculopathy, which may be part of the spectrum of retinal manifestations in MELAS. Pediatric-onset vitelliform maculopathy in MELAS may be under-diagnosed due to its asymptomatic nature. Given the known risk of choroidal neovascularization in vitelliform maculopathy, it is important to identify these patients for proper surveillance.
PubMed: 37096132
DOI: 10.1016/j.ajoc.2023.101842