Objective
GNAO1‐related disorders (OMIM #615473 and #617493), caused by variants in the GNAO1 gene, are characterized by developmental delay or intellectual disability, hypotonia, movement disorders, ...and epilepsy. Neither a genotype–phenotype correlation nor a clear severity score have been established for this disorder. The objective of this prospective and retrospective observational study was to develop a severity score for GNAO1‐related disorders, and to delineate the correlation between the underlying molecular mechanisms and clinical severity.
Methods
A total of 16 individuals with GNAO1‐related disorders harboring 12 distinct missense variants, including four novel variants (p.K46R, p.T48I, p.R209P, and p.L235P), were examined with repeated clinical assessments, video‐electroencephalogram monitoring, and brain magnetic resonance imaging. The molecular pathology of each variant was delineated using a molecular deconvoluting platform.
Results
The patients displayed a wide variability in the severity of their symptoms. This heterogeneity was well represented in the GNAO1‐related disorders severity score, with a broad range of results. Patients with the same variant had comparable severity scores, indicating that differences in disease profiles are not due to interpatient variability, but rather, to unique disease mechanisms. Moreover, we found a significant correlation between clinical severity scores and molecular mechanisms.
Interpretation
The clinical score proposed here provides further insight into the correlation between pathophysiology and phenotypic severity in GNAO1‐related disorders. We found that each variant has a unique profile of clinical phenotypes and pathological molecular mechanisms. These findings will contribute to better understanding GNAO1‐related disorders. Additionally, the severity score will facilitate standardization of patients categorization and assessment of response to therapies in development. ANN NEUROL 2023;94:987–1004
Objective
To delineate the epileptic phenotype of LAMA2‐related muscular dystrophy (MD) and correlate it with the neuroradiological and muscle biopsy findings, as well as the functional motor ...phenotype.
Methods
Clinical, electrophysiological, neuroradiological, and histopathological data of 25 patients with diagnosis of LAMA2‐related MD were analyzed.
Results
Epilepsy occurred in 36% of patients with LAMA2‐related MD. Mean age at first seizure was 8 years. The most common presenting seizure type was focal‐onset seizures with or without impaired awareness. Visual aura and autonomic signs, including vomiting, were frequently reported. Despite a certain degree of variability, bilateral occipital or temporo‐occipital epileptiform abnormalities were by far the most commonly observed. Refractory epilepsy was found in 75% of these patients. Epilepsy in LAMA2‐related MD was significantly more prevalent in those patients in whom the cortical malformations were more extensive. In contrast, the occurrence of epilepsy was not found to be associated with the patients' motor ability, the size of their white matter abnormalities, or the amount of residual merosin expressed on muscle.
Significance
The epileptic phenotype of LAMA2‐related MD is characterized by focal seizures with prominent visual and autonomic features associated with EEG abnormalities that predominate in the posterior quadrants. A consistent correlation between epileptic phenotype and neuroimaging was identified, suggesting that the extension of the polymicrogyria may serve as a predictor of epilepsy occurrence.
Epilepsy and cognition: the role of antiepileptic drugs García-Peñas, Juan José; Fournier-Del Castillo, M Concepción; Domínguez-Carral, Jana
Revista de neurologiá,
2014-Feb-24, 20140224, Letnik:
58 Suppl 1
Journal Article
Recenzirano
Multiple factors underlie the cognitive changes associated with epilepsy, including the effect of antiepileptic drug (AED) therapy itself. The use of AEDs in the management of epilepsy requires an ...ongoing risk-benefit analysis that attempts to maximize seizure control while minimizing adverse cognitive side-effects.
This review focuses on the global and specific cognitive effects of the classic and the new AEDs.
All of the established AEDs can produce cognitive side effects, which are increased with polypharmacy and with increasing dosage and anticonvulsant blood levels. The main disorders are a diminished reaction and information processing time with alterations affecting memory, attention and language. Further, there is much debate concerning the existence and clinical importance of differential AED cognitive side effects and a large portion of the literature examining the comparative cognitive effects of AEDs is limited by inadequate study designs.
Cognitive side effects of antiepileptic drugs are common and can negatively affect tolerability, compliance, and long-term retention of the treatment. The role of cognitive side effects should be kept in proper perspective when choosing AED therapy. It is important to be able to recognize early these effects and to put them into perspective as to how they affect our patients.
Background GNAO1 -related disorders ( GNAO1 -RD) encompass a diverse spectrum of neurodevelopmental and movement disorders arising from variants in the GNAO1 gene. Dyskinetic crises, marked by sudden ...and intense exacerbations of abnormal involuntary movements, present a significant challenge in GNAO1 -RD. Objectives This study aimed to establish a standardized framework for understanding dyskinetic crises, addressing crucial aspects such as definition, triggers, diagnostic criteria, complications, and management strategies. Methods A Delphi consensus process was conducted involving international experts in GNAO1 -RD. The panel of thirteen experts participated in three voting rounds, discussing 90 statements generated through a literature review and clinical expertise. Results Consensus was achieved on 31 statements, defining dyskinetic crises as abrupt, paroxysmal episodes involving distinct abnormal movements in multiple body regions, triggered by emotional stress or infections. Dyskinetic crises may lead to functional impairment and complications, emphasizing the need for prompt recognition. While individualized pharmacological recommendations were not provided, benzodiazepines and clonidine were suggested for acute crisis management. Chronic treatment options included tetrabenazine, benzodiazepines, gabapentin, and clonidine. Deep brain stimulation should be considered early in the treatment of refractory or prolonged dyskinetic crisis. Conclusion This consensus provides a foundation for understanding and managing dyskinetic crises in GNAO1 -RD for clinicians, caregivers, and researchers. The study emphasizes the importance of targeted parental and caregiver education, which enables early recognition and intervention, thereby potentially minimizing both short- and long-term complications. Future research should concentrate on differentiating dyskinetic crises from other neurological events and investigating potential risk factors that influence their occurrence and nature. The proposed standardized framework improves clinical management, stakeholder communication, and future GNAO1 -RD research.
Epilepsy in Duchenne and Becker muscular dystrophies Armijo Gómez, Jesus Alfonso; Fernandez‐Garcia, Miguel A.; Camacho, Ana ...
Annals of clinical and translational neurology,
June 2024, Letnik:
11, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Objective
Duchenne and Becker muscular dystrophies (DMD and BMD) are dystrophinopathies caused by variants in DMD gene, resulting in reduced or absent dystrophin. These conditions, characterized by ...muscle weakness, also manifest central nervous system (CNS) comorbidities due to dystrophin expression in the CNS. Prior studies have indicated a higher prevalence of epilepsy in individuals with dystrophinopathy compared to the general population. Our research aimed to investigate epilepsy prevalence in dystrophinopathies and characterize associated electroencephalograms (EEGs) and seizures.
Methods
We reviewed 416 individuals with dystrophinopathy, followed up at three centers between 2010 and 2023, to investigate the lifetime epilepsy prevalence and characterize EEGs and seizures in those individuals diagnosed with epilepsy. Associations between epilepsy and type of dystrophinopathy, genotype, and cognitive involvement were studied.
Results
Our study revealed a higher epilepsy prevalence than the general population (1.4%; 95% confidence interval: 0.7–3.2%), but notably lower than previously reported in smaller dystrophinopathy cohorts. No significant differences were found in epilepsy prevalence between DMD and BMD or based on underlying genotypes. Cognitive impairment was not found to be linked to higher epilepsy rates. The most prevalent epilepsy types in dystrophinopathies resembled those observed in the broader pediatric population, with most individuals effectively controlled through monotherapy.
Interpretation
The actual epilepsy prevalence in dystrophinopathies may be markedly lower than previously estimated, possibly half or even less. Our study provides valuable insights into the epilepsy landscape in individuals with dystrophinopathy, impacting medical care, especially for those with concurrent epilepsy.
The social, language, and behavioural problems that occur with autism suggest that this syndrome affects a functionally diverse and widely distributed set of neural systems.
To review the molecular ...pathways involved in synaptic growth, development, and stability of human synapses. We also examine the genes implicated in synaptogenesis which have been associated with autism. In particular, we highlight the role of these genes in synaptic cell adhesion, organization of presynaptic and postsynaptic specializations, growth signaling pathways, and endosomal function.
Proper brain function requires stringent balance of excitatory and inhibitory synapse formation during neural circuit assembly. Mutation of genes that normally sculpt and maintain this balance results in severe dysfunction, causing neurodevelopmental disorders including autism, epilepsy, Angelman syndrome, fragile X syndrome, and Rett syndrome. Such mutations may result in defective architectural structuring of synaptic connections, molecular assembly of synapses and/or functional synaptogenesis.
Increased knowledge of abnormal mechanisms of human synaptogenesis may lead to define different etio-pathogenic models of autism and to understand how far abnormal cell/synaptic growth and synaptic function could be reversed.
Thymine kinase 2 (TK2) is a mitochondrial matrix protein encoded in nuclear DNA and phosphorylates the pyrimidine nucleosides: thymidine and deoxycytidine. Autosomal recessive
mutations cause a ...spectrum of disease from infantile onset to adult onset manifesting primarily as myopathy.
To perform a retrospective natural history study of a large cohort of patients with TK2 deficiency.
The study was conducted by 42 investigators across 31 academic medical centres.
We identified 92 patients with genetically confirmed diagnoses of TK2 deficiency: 67 from literature review and 25 unreported cases. Based on clinical and molecular genetics findings, we recognised three phenotypes with divergent survival: (1) infantile-onset myopathy (42.4%) with severe mitochondrial DNA (mtDNA) depletion, frequent neurological involvement and rapid progression to early mortality (median post-onset survival (POS) 1.00, CI 0.58 to 2.33 years); (2) childhood-onset myopathy (40.2%) with mtDNA depletion, moderate-to-severe progression of generalised weakness and median POS at least 13 years; and (3) late-onset myopathy (17.4%) with mild limb weakness at onset and slow progression to respiratory insufficiency with median POS of 23 years. Ophthalmoparesis and facial weakness are frequent in adults. Muscle biopsies show multiple mtDNA deletions often with mtDNA depletion.
In TK2 deficiency, age at onset, rate of weakness progression and POS are important variables that define three clinical subtypes. Nervous system involvement often complicates the clinical course of the infantile-onset form while extraocular muscle and facial involvement are characteristic of the late-onset form. Our observations provide essential information for planning future clinical trials in this disorder.
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