Pacienti s epilepsií mají vyšší mortalitu a náhlá neočekávaná smrt (SUDEP, sudden unexpected death in epilepsy) je nejčastější příčina smrti přímo související s epilepsií. V přehledném článku autor popisuje současný stav znalostí o rizikových faktorech, uvažovaných mechanizmech a možné prevenci SUDEP. Kontroverzní je otázka, zda o riziku SUDEP informovat všechny pacienty.

Patients with epilepsy have increased mortality and sudden unexpected death (SUDEP) is the most frequent direct epilepsy-related cause of death. In this review the author summarizes risk factor, proposed mechanisms and potential preventive strategies. Universal discussion of SUDEP with all patients remains controversial.

• Keywords
• iktální, záchvat,
• MeSH
• Anticonvulsants adverse effects   therapeutic use   MeSH
• Bradycardia MeSH
• Epilepsy complications   mortality   MeSH
• Drug Therapy, Combination adverse effects   MeSH
• Comorbidity MeSH
• Humans MeSH
• Mortality MeSH
• Death, Sudden epidemiology   etiology   prevention & control   MeSH
• Cause of Death MeSH
• Risk Factors MeSH
• Truth Disclosure MeSH
• Sleep MeSH
• Arrhythmias, Cardiac epidemiology   complications   mortality   MeSH
• Sleep Apnea Syndromes complications   MeSH
• Seizures complications   mortality   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Review MeSH

• MeSH
• Adult MeSH
• Epilepsy physiopathology   pathology   psychology   MeSH
• Humans MeSH
• Death, Sudden etiology   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Publication type
• Case Reports MeSH

• MeSH
• Electrocardiography MeSH
• Epilepsy epidemiology   complications   MeSH
• Cardiovascular Diseases epidemiology   diagnosis   MeSH
• Death, Sudden, Cardiac epidemiology   MeSH
• Publication type
• Academic Dissertation MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• neurologie
• kardiologie

Voltage-gated sodium channel β1 subunits are essential proteins that regulate excitability. They modulate sodium and potassium currents, function as cell adhesion molecules and regulate gene transcription following regulated intramembrane proteolysis. Biallelic pathogenic variants in SCN1B, encoding β1, are linked to developmental and epileptic encephalopathy 52, with clinical features overlapping Dravet syndrome. A recessive variant, SCN1B-c.265C>T, predicting SCN1B-p.R89C, was homozygous in two children of a non-consanguineous family. One child was diagnosed with Dravet syndrome, while the other had a milder phenotype. We identified an unrelated biallelic SCN1B-c.265C>T patient with a clinically more severe phenotype than Dravet syndrome. We used CRISPR/Cas9 to knock-in SCN1B-p.R89C to the mouse Scn1b locus (Scn1bR89/C89). We then rederived the line on the C57BL/6J background to allow comparisons between Scn1bR89/R89 and Scn1bC89/C89 littermates with Scn1b+/+ and Scn1b-/- mice, which are congenic on C57BL/6J, to determine whether the SCN1B-c.265C>T variant results in loss-of-function. Scn1bC89/C89 mice have normal body weights and ∼20% premature mortality, compared with severely reduced body weight and 100% mortality in Scn1b-/- mice. β1-p.R89C polypeptides are expressed in brain at comparable levels to wild type. In heterologous cells, β1-p.R89C localizes to the plasma membrane and undergoes regulated intramembrane proteolysis similar to wild type. Heterologous expression of β1-p.R89C results in sodium channel α subunit subtype specific effects on sodium current. mRNA abundance of Scn2a, Scn3a, Scn5a and Scn1b was increased in Scn1bC89/C89 somatosensory cortex, with no changes in Scn1a. In contrast, Scn1b-/- mouse somatosensory cortex is haploinsufficient for Scn1a, suggesting an additive mechanism for the severity of the null model via disrupted regulation of another Dravet syndrome gene. Scn1bC89/C89 mice are more susceptible to hyperthermia-induced seizures at post-natal Day 15 compared with Scn1bR89/R89 littermates. EEG recordings detected epileptic discharges in young adult Scn1bC89/C89 mice that coincided with convulsive seizures and myoclonic jerks. We compared seizure frequency and duration in a subset of adult Scn1bC89/C89 mice that had been exposed to hyperthermia at post-natal Day 15 versus a subset that were not hyperthermia exposed. No differences in spontaneous seizures were detected between groups. For both groups, the spontaneous seizure pattern was diurnal, occurring with higher frequency during the dark cycle. This work suggests that the SCN1B-c.265C>T variant does not result in complete loss-of-function. Scn1bC89/C89 mice more accurately model SCN1B-linked variants with incomplete loss-of-function compared with Scn1b-/- mice, which model complete loss-of-function, and thus add to our understanding of disease mechanisms as well as our ability to develop new therapeutic strategies.

• Publication type
• Journal Article MeSH

BACKGROUND: Sudden unexpected death in epilepsy (SUDEP) is a fatal complication experienced by otherwise healthy epilepsy patients. Dravet syndrome (DS) is an inherited epileptic disorder resulting from loss of function of the voltage-gated sodium channel, NaV 1.1, and is associated with particularly high SUDEP risk. Evidence is mounting that NaVs abundant in the brain also occur in the heart, suggesting that the very molecular mechanisms underlying epilepsy could also precipitate cardiac arrhythmias and sudden death. Despite marked reduction of NaV 1.1 functional expression in DS, pathogenic late sodium current (INa,L) is paradoxically increased in DS hearts. However, the mechanisms by which DS directly impacts the heart to promote sudden death remain unclear. OBJECTIVES: In this study, the authors sought to provide evidence implicating remodeling of Na+ - and Ca2+ -handling machinery, including NaV 1.6 and Na+/Ca2+exchanger (NCX) within transverse (T)-tubules in DS-associated arrhythmias. METHODS: The authors undertook scanning ion conductance microscopy (SICM)-guided patch clamp, super-resolution microscopy, confocal Ca2+ imaging, and in vivo electrocardiography studies in Scn1a haploinsufficient murine model of DS. RESULTS: DS promotes INa,L in T-tubular nanodomains, but not in other subcellular regions. Consistent with increased NaV activity in these regions, super-resolution microscopy revealed increased NaV 1.6 density near Ca2+release channels, the ryanodine receptors (RyR2) and NCX in DS relative to WT hearts. The resulting INa,L in these regions promoted aberrant Ca2+ release, leading to ventricular arrhythmias in vivo. Cardiac-specific deletion of NaV 1.6 protects adult DS mice from increased T-tubular late NaV activity and the resulting arrhythmias, as well as sudden death. CONCLUSIONS: These data demonstrate that NaV 1.6 undergoes remodeling within T-tubules of adult DS hearts serving as a substrate for Ca2+ -mediated cardiac arrhythmias and may be a druggable target for the prevention of SUDEP in adult DS subjects.

• MeSH
• Epilepsies, Myoclonic * genetics   MeSH
• Myocytes, Cardiac metabolism   MeSH
• Humans MeSH
• Mice, Knockout MeSH
• Mice MeSH
• Sudden Unexpected Death in Epilepsy MeSH
• NAV1.6 Voltage-Gated Sodium Channel * genetics   metabolism   MeSH
• Sodium-Calcium Exchanger genetics   metabolism   MeSH
• Arrhythmias, Cardiac genetics   MeSH
• Calcium metabolism   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

PURPOSE: To define the phenotypic and mutational spectrum of epilepsies related to DEPDC5, NPRL2 and NPRL3 genes encoding the GATOR1 complex, a negative regulator of the mTORC1 pathway METHODS: We analyzed clinical and genetic data of 73 novel probands (familial and sporadic) with epilepsy-related variants in GATOR1-encoding genes and proposed new guidelines for clinical interpretation of GATOR1 variants. RESULTS: The GATOR1 seizure phenotype consisted mostly in focal seizures (e.g., hypermotor or frontal lobe seizures in 50%), with a mean age at onset of 4.4 years, often sleep-related and drug-resistant (54%), and associated with focal cortical dysplasia (20%). Infantile spasms were reported in 10% of the probands. Sudden unexpected death in epilepsy (SUDEP) occurred in 10% of the families. Novel classification framework of all 140 epilepsy-related GATOR1 variants (including the variants of this study) revealed that 68% are loss-of-function pathogenic, 14% are likely pathogenic, 15% are variants of uncertain significance and 3% are likely benign. CONCLUSION: Our data emphasize the increasingly important role of GATOR1 genes in the pathogenesis of focal epilepsies (>180 probands to date). The GATOR1 phenotypic spectrum ranges from sporadic early-onset epilepsies with cognitive impairment comorbidities to familial focal epilepsies, and SUDEP.

• MeSH
• Brugada Syndrome genetics   mortality   physiopathology   MeSH
• Child MeSH
• Epilepsy complications   epidemiology   genetics   physiopathology   MeSH
• Genetic Predisposition to Disease MeSH
• Infant MeSH
• Humans MeSH
• Adolescent MeSH
• Mechanistic Target of Rapamycin Complex 1 genetics   MeSH
• Multiprotein Complexes genetics   MeSH
• INDEL Mutation genetics   MeSH
• Loss of Function Mutation genetics   MeSH
• Tumor Suppressor Proteins genetics   MeSH
• Infant, Newborn MeSH
• Child, Preschool MeSH
• GTPase-Activating Proteins genetics   MeSH
• Repressor Proteins genetics   MeSH
• Pedigree MeSH
• Signal Transduction genetics   MeSH
• DNA Copy Number Variations genetics   MeSH
• Seizures complications   epidemiology   genetics   physiopathology   MeSH
• Check Tag
• Child MeSH
• Infant MeSH
• Humans MeSH
• Adolescent MeSH
• Male MeSH
• Infant, Newborn MeSH
• Child, Preschool MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

• MeSH
• Genetic Testing methods   MeSH
• Humans MeSH
• Sudden Unexpected Death in Epilepsy pathology   MeSH
• Sudden Infant Death pathology   MeSH
• Death, Sudden, Cardiac * etiology   pathology   prevention & control   MeSH
• Autopsy methods   standards   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH

Dravetové syndrom (DS) je ve většině případů podmíněn mutací podjednotky sodíkového kanálu (SCN1A), začíná v dětském věku, nicméně se jedná o onemocnění celoživotní. V rámci článku se soustředíme na charakteristiky pacientů s DS v dospělosti. Z hlediska epileptologie je pro nás zásadní výskyt epileptických záchvatů. V dospělosti se jedná především o konvulzivní záchvaty (generalizované tonicko­‐klonické, tonické nebo fokální záchvaty s přechodem do bilaterálně tonicko­‐klonických záchvatů), které mohou být provokovány zvýšením tělesné teploty nebo emocemi. Nicméně rodiče/pečující o pacienty s DS uvádějí často další projevy onemocnění jako velmi významné, mnohdy více omezující než vlastní epileptické záchvaty. Jedná se především o kognitivní obtíže, poruchy učení, poruchy chování, motorické problémy (crouch gait, parkinsonismus, ataxii, abnormální postury při stoji a chůzi), poruchy spánku a kardiální abnormity. U DS je rovněž vysoké riziko náhlého neočekávaného úmrtí (SUDEP, sudden unexpected death in epilepsy). V druhé části článku se věnujeme terapii. V současnosti existují doporučení pro pacienty s DS. První linii terapie představuje valproát a klobazam. V druhé linii se uplatňují specifické léky indikované pro tento syndrom, konkrétně se jedná o stiripentol (Diacomit), fenfluramin (Fintepla) a vysoce čištěný kanabidiol (CBD, v České republice dostupný jako Epidyolex).

Dravet syndrome (DS) is predominantly caused by a mutation in the sodium channel subunit (SCN1A). It begins in childhood but is a lifelong condition. In this article, we focus on the characteristics of adult patients with DS. From an epileptological perspective, the occurrence of epileptic seizures is crucial. In adulthood, there are mainly clonic seizures (generalized tonic-clonic seizures, tonic seizures or focal seizures to bilateral tonic-clonic seizures). They can be provoked by increased body temperature or by emotions. However, parents/caregivers of patients with DS often report other manifestations of the disease as very significant, often more limiting than the seizures themselves. These primarily include cognitive difficulties, learning disorders, behavioral issues, motor problems (crouch gait, parkinsonism, ataxia, abnormal postures while standing and walking), sleep disorders, and cardiac abnormalities. There is also a high risk of sudden unexpected death in epilepsy (SUDEP) in DS. The second part of the article is dedicated to therapy. Currently, there are recommendations for patients with DS. The first line of therapy includes valproate and clobazam. The second line involves specific drugs indicated for this syndrome, specifically stiripentol (Diacomit), fenfluramine (Fintepla), and cannabidiol (CBD, available in the Czech Republic as Epidyolex).

• MeSH
• Anticonvulsants administration & dosage   MeSH
• Adult * MeSH
• Epilepsies, Myoclonic * drug therapy   pathology   MeSH
• Fenfluramine administration & dosage   economics   MeSH
• Cannabidiol administration & dosage   pharmacology   MeSH
• Clinical Studies as Topic MeSH
• Drug Prescriptions MeSH
• Humans MeSH
• Motor Disorders etiology   pathology   MeSH
• Check Tag
• Adult * MeSH
• Humans MeSH
• Publication type
• Review MeSH

The risk factors for SUDEP are undoubtedly heterogenous but the main factor is the frequency of generalized tonic-clonic seizures with apnoea and/or cardiac abnormalities likely precipitating the lethal event. By its very nature modelling SUDEP experimentally is challenging, yet insights into the nature of the lethal event and precipitating factors are vital in order to understand and prevent fatalities. Acute animal models, which induce status epilepticus (SE), can be used to help understand pathophysiological processes during and following seizures, which sometimes lead to death. The most commonly used method to induce seizures and status epilepticus is systemic administration of an ictogenic agent. Microinjection of such agents into restricted regions within the brain induces a more localised epileptic focus and circumvents the risk of direct actions on cardiorespiratory control centres. Both approaches have revealed substantial cardiovascular and respiratory consequences, including death as a result of apnoea, which may be of central origin, obstructive due to laryngospasm or, at least in genetically modified mice, a result of spreading depolarisation to medullary respiratory control centres. SUDEP is by definition a result of epilepsy, which in turn is diagnosed on the basis of two or more unprovoked seizures. The incidence of tonic-clonic seizures is the main risk factor, raising the possibility that repeated seizures cause cumulative pathological and/or pathophysiological changes that contribute to the risk of SUDEP. Chronic experimental models, which induce repeated seizures that in some cases lead to death, do show progressive development of pathophysiological changes in the myocardium, e.g. prolongation of QT the interval of the ECG or, over longer periods, ventricular hypertrophy. However, the currently available evidence indicates that seizure-related deaths are primarily due to apnoeas, but cardiac factors, particularly cumulative cardiac pathophysiologies due to repeated seizures, are potential contributing factors.

• MeSH
• Epilepsy * MeSH
• Incidence MeSH
• Mice MeSH
• Sudden Unexpected Death in Epilepsy * MeSH
• Risk Factors MeSH
• Seizures chemically induced   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

OBJECTIVE: To determine electrical changes in the heart in a chronic, nonstatus model of epilepsy. METHODS: Electrocorticography (ECoG) and electrocardiography (ECG) of nine animals (five made epileptic by intrahippocampal injection of tetanus neurotoxin (TeNT) and four controls), are monitored continuously by radiotelemetry for up to 7 weeks. RESULTS: Epileptic animals develop a median of 168 seizures, with postictal tachycardias reaching a mean of 487 beats/min and lasting a mean of 661 seconds. Ictal changes in heart rate include tachycardia and in the case of convulsive seizures, bradyarrhythmias resembling Mobitz type 1 second-degree atrioventricular block; notably the P-R interval increased before block. Postictally, the amplitude of T wave increases. Interictally, QT dependence on RR is modest and conventional QT corrections prove ineffective. Interictal QT intervals, measured at a heart rate of 400 bpm, increased from 65 to 75 ms, an increase dependent on seizure incidence over the preceding 10-14 days. SIGNIFICANCE: Repeated seizures induce a sustained tachycardia and increase in QT interval of the ECG and evoke arrhythmias including periods of atrioventricular block during Racine type 4 and 5 seizures. These changes in cardiac function may predispose to development in fatal arrhythmias and sudden death in humans with epilepsy.

• MeSH
• Bradycardia etiology   MeSH
• Electrocardiography MeSH
• Electrocorticography MeSH
• Rats MeSH
• Sudden Unexpected Death in Epilepsy etiology   MeSH
• Neurotoxins toxicity   MeSH
• Rats, Wistar MeSH
• Tachycardia etiology   MeSH
• Tetanus Toxin toxicity   MeSH
• Seizures chemically induced   complications   physiopathology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH