Preventing tomorrow's sudden cardiac death in epilepsy today: what should physicians know about this?

Cardiac arrest associated with epileptic seizures: A case report with simultaneous EEG and ECG

Ictal asystole is a rare, probably underestimated manifestation of epileptic seizures whose pathophysiology is still debated. This report describes two patients who had cardiac asystole at the end of their seizure. The first patient was a 13-year-old boy with complex partial seizures.. His MRI showed symmetrical signal abnormality in the bilateral parietooccipital lobe accompanied by mild gliosis and volume loss. During a 3-day long-term video-EEG monitoring, he had cardiac arrest at the end of one of his seizures that was secondarily generalized. The second one was a 42-year-old veteran with penetrating head trauma in the left frontal lobe due to shell injury. During long-term video-EEG monitoring, he had one generalized tonic-clonic seizure accompanied by bradycardia and cardiac asystole. Asystoles could have a role in the incidence of sudden unexpected death in epilepsy (SUDEP), meaning that the presence of ictal bradycardia is a risk factor for SUDEP. In cases of epileptic cardiac dysrhythmia, prolonged simultaneous EEG/ECG monitoring may be required. Cardiological investigation should be included in epilepsy management.

The effects of sleep deprivation on microRNA expression in rats submitted to pilocarpine-induced status epilepticus

Epilepsy is a neurological disorder with significant prevalence and the individuals affected by this disease have a great probability of occurrence of a lethal phenomenon known as Sudden Unexpected Death in Epilepsy (SUDEP). SUDEP occurs mainly during the night and probably during sleep. The pathophysiological mechanisms involved in this lethal phenomenon are still obscure and new evidences that could corroborate in this area are warranted. Thus, the aim of the present study was to evaluate the effect of sleep deprivation in the expression of microRNA (miRNA) in the frontal cortex and heart tissues of adult male rats after 50days of saline (SAL) or pilocarpine-induced status epilepticus (PILO). Initially 389 miRNA expressions were evaluated between SAL and PILO groups by microarray. Subsequently, 3 differentially expressed miRNAs of each tissue were investigated after total sleep deprivation (TSD 6h) and paradoxical sleep deprivation (PSD 24h). Still, it was analyzed that the effects of sleep rebound with equivalent duration of PSD and TSD. There was a significant increase of miR-146a expression, an important inflammatory modulator in the frontal cortex of PILO rats when compared to SAL animals. Animals treated with pilocarpine were affected by TSD (through overexpression of miRNAs related to inflammatory process) and these changes were maintained even after a sleep window of 6h. In contrast, miRNAs associated with heart diseases were down-regulated in PSD rebound, suggesting a possible restoration of homeostasis in cardiovascular system of SAL and PILO groups.

Epileptologists probe vagus nerve stimulation in children with refractory epilepsy: a promise against sudden unexpected death in epilepsy

It is clear that sudden unexpected death in epilepsy (SUDEP) is mainly a problem for people with refractory epilepsy, but our understanding of the best way to its prevention is still incomplete. Although the pharmacological treatments available for epilepsies have expanded, some antiepileptic drugs are still limited in clinical efficacy. In the present paper, we described an experience with vagus nerve stimulation (VNS) treatment by opening space and providing the opportunity to implement effective preventative maps to reduce the incidence of SUDEP in children and adolescents with refractory epilepsy.

Experimental and clinical findings from physical exercise as complementary therapy for epilepsy

Complementary therapies for preventing or treating epilepsy have been extensively used. This review focuses on the positive effects of physical exercise programs observed in clinical studies and experimental models of epilepsy and their significance as a complementary therapy for epilepsy. Information about the antiepileptogenic and neuroprotective effects of exercise is highlighted. Considering that exercise can exert beneficial actions such as reduction of seizure susceptibility, reduction of anxiety and depression, and consequently, improvement of quality of life of individuals with epilepsy, exercise can be a potential candidate as non-pharmacological treatment of epilepsy.

The promise of omega-3 against sudden unexpected death in epilepsy: until further notice, it remains innocent, until proven guilty

The present paper highlighted the importance of the recommended levels of fish consumption or omega-3 supplementation in order to minimize the frequency of seizures in people with uncontrolled epilepsy and, especially, to reduce the occurrence of sudden unexpected death in epilepsy (SUDEP).

Epilepsy kills

People with epilepsy are more likely to die prematurely, and the most common epilepsy-related category of death is sudden unexpected death in epilepsy (SUDEP). Thus, the purpose of this article was to alert the scientific community about SUDEP.

The utility of omega-3 fatty acids in epilepsy: more than just a farmed tilapia!

The epilepsies are one of the most common serious brain disorders and 20 to 30% of people developing epilepsy continue to have seizures and are refractory to treatment with the currently available therapies. Approximately one in a 1000 patients with chronic epilepsy will die suddenly, unexpectedly, and without explanation, even with post-mortem examination and this phenomenon is called sudden unexplained death in epilepsy (SUDEP). Understanding the mechanisms underlying SUDEP may lead to the identification of previously unrecognized risk factors that are more amenable to correction. We discuss here the possible implications of omega-3 fatty acids consumption on SUDEP prevention.

Sudden unexpected death in epilepsy: an important concern

Epilepsy is one of the most common neurologic problems worldwide. Unfortunately, individuals with epilepsy are at higher risk of death than the general population, and sudden unexpected death in epilepsy is the most important direct epilepsy-related cause of death. In this review article, our research group focused on the risk factors, mechanisms and preventative measures obtained from clinical and experimental studies on sudden unexpected death in epilepsy.

Does sudden unexpected death in children with epilepsy occur more frequently in those with high seizure frequency?

People with epilepsy are more likely to die prematurely and the most common epilepsy-related category of death is sudden unexpected death in epilepsy (SUDEP). Several studies have reported a moderate or high seizure frequency among SUDEP cases and SUDEP is considered rare in patients in remission.

METHOD

We reviewed the occurrence of SUDEP in our epilepsy unit over an 8-year period to identify a potential association between seizure frequency and SUDEP occurrence in children with epilepsy.

RESULTS

From 835 patients evaluated, 12 had suffered SUDEP and nearly all of the SUDEP cases in our children are related to chronic uncontrolled epilepsy (daily--50.0%, two to four/week--41.7%, monthly--8.3%).

CONCLUSION

SUDEP is not a rare event in children and increased mortality was recorded in those individuals who had not responded to pharmacologic treatment. Improved seizure control seems to be one of the most important measures to prevent SUDEP.

Carbamazepine does not alter the intrinsic cardiac function in rats with epilepsy

Among the causes for sudden unexpected death (SUDEP) in epilepsy, the effects of antiepileptic drugs on the heart have been poorly explored. Based on this, the aim of our study was to evaluate the heart rate (in vivo and isolated ex vivo) and ventricular pressure (isolated ex vivo) of rats with and without epilepsy treated with carbamazepine. Four groups of adult, male Wistar rats (200-250 g) were studied: [A] control rats (n=8), received neither pilocarpine nor carbamazepine [B] carbamazepine-treated rats (n=8), received a daily dose of 120 mg/Kg, i.p. of carbamazepine for two weeks; [C] rats with epilepsy that received just saline solution (n=8); [D] rats with epilepsy that received a daily dose of 120 mg/Kg, i.p. of carbamazepine for two weeks (n=8). Our results showed significant increase in heart rate in animals with epilepsy (with and without the use of carbamazepine) when compared to the control groups in vivo. In contrast, we did not find differences during isolated ex vivo experiments comparing animals with and without epilepsy and despite the use of carbamazepine. Our results suggest that, in isolation, carbamazepine may not be a potential risk factor for sudden unexpected death in epilepsy.

Thalamic nuclear abnormalities as a contributory factor in sudden cardiac deaths among patients with schizophrenia

Patients with schizophrenia have a two- to three-fold increased risk of premature death as compared to patients without this disease. It has been established that patients with schizophrenia are at a high risk of developing cardiovascular disease. Moreover, an important issue that has not yet been explored is a possible existence of a "cerebral" focus that could trigger sudden cardiac death in patients with schizophrenia. Along these lines, several structural and functional alterations in the thalamic complex are evident in patients with schizophrenia and have been correlated with the symptoms manifested by these patients. With regard to abnormalities on the cellular and molecular level, previous studies have shown that schizophrenic patients have fewer neuronal projections from the thalamus to the prefrontal cortex as well as a reduced number of neurons, a reduced volume of either the entire thalamus or its subnuclei, and abnormal glutamate signaling. According to the glutamate hypothesis of schizophrenia, hypofunctional corticostriatal and striatothalamic projections are directly involved in the pathophysiology of the disease. Animal and post-mortem studies have provided a large amount of evidence that links the sudden unexpected death in epilepsy (SUDEP) that occurs in patients with schizophrenia and epilepsy to thalamic changes. Based on the results of these prior studies, it is clear that further research regarding the relationship between the thalamus and sudden cardiac death is of vital importance.

Subclinical hyperthyroidism and sudden unexpected death in epilepsy

Epilepsy is the most common serious neurological condition and sudden unexpected death in epilepsy (SUDEP) is the most important direct epilepsy-related cause of death. Information concerning risk factors for SUDEP is conflicting, but high seizure frequency is a potential risk factor. Additionally, potential pathomechanisms for SUDEP are unknown, but it is very probable that cardiac arrhythmias during and between seizures or transmission of epileptic activity to the heart via the autonomic nervous system potentially play a role. In parallel, several studies have shown a link between hormones and epilepsy. However, exact knowledge regarding the association of thyroid hormones and epilepsy is lacking. As subclinical hyperthyroidism has been linked with increased risk of cardiovascular disease, we propose in this paper that SUDEP, at least in some cases, could be related with subclinical thyroid dysfunction.

Electric countershock and cold stress effects on liver and adrenal gland

OBJECTIVES

Cold exposure induces glycogen and lipid depletion in the liver and the adrenal gland, respectively. However, no previous study has determined the effects of electrical countershock on those tissues. We aimed to evaluate the effects of electrical countershock on lipid depletion in the adrenal gland and on glycogen depletion in the liver.

METHODS

We used 40 male Wistar rats divided into four groups: the control group, in which the animals were subjected to a resting period of seven days; the electrical discharge group, in which the animals were subjected to a resting period followed by administration of ten 300-mV electrical discharges; the electrical post-discharge group, in which the animals received ten electrical shocks (300 mV) followed by rest for seven consecutive days; and the cold stress group, in which the animals were subjected to a resting period and were then exposed to -8 degrees C temperatures for four hours. All animals underwent a laparotomy after treatment. The lipid and glycogen depletions are presented using intensity levels (where + = low intensity and ++++ = high intensity, with intermediate levels in between).

RESULTS

The rats exposed to the cold stress presented the highest glycogen and lipid depletion in the liver and the adrenal gland, respectively. Furthermore, we noted that the electrical countershock significantly increased lipid depletion in the adrenal gland and glycogen depletion in the liver. One week after the electrical countershock, the liver and adrenal gland profiles were similar to that of the control group.

CONCLUSION

Electrical countershock immediately increased the glycogen depletion in the liver and the lipid depletion in the adrenal gland of rats.

Alcohol consumption and sudden unexpected death in epilepsy: experimental approach

Using the pilocarpine model of epilepsy, we investigated the effects of alcohol consumption on the frequency of seizures in animals with epilepsy as well the underlying a possible association between alcohol intake and sudden unexpected death in epilepsy (SUDEP) occurrence. Rats were divided randomly into two groups: (A) rats with epilepsy and (B) rats with epilepsy that received a daily dose of ethanol solution (350 mg kg(-1), i.p.) for 30 days. The basal frequency of seizures observed in the A and B groups during the first 30 days were 3.4+/-1.5 and 3.2+/-1.9 seizures per week per animal, respectively. In B group, it was observed a significant seizure increase (11.6+/-5.3) during the first 2 weeks of alcohol administration and quite interesting, one rat died suddenly after a generalized tonic-clonic seizure during this period. We concluded in our experimental study that exist a possible association between alcohol abuse and SUDEP occurrence.

Evaluation of intense physical effort in subjects with temporal lobe epilepsy

People with epilepsy have been discouraged from participating in physical activity due to the fear that it will exacerbate seizures. Although the beneficial effect of aerobic exercise in people with epilepsy, little objective evidence regarding the intensity of exercise has been reported. We investigated the effect of incremental physical exercise to exhaustion in people with epilepsy. Seventeen persons with temporal lobe epilepsy and twenty one control healthy subjects participated in this study. Both groups were submitted to echocolordoppler and electrocardiogram at rest and during physical effort. None of patients reported seizures during physical effort or in the recovery period of ergometric test. Both groups presented physiological heart rate and blood pressure responses during the different stages of the ergometric test. Only few patients presented electrocardiography or echocardiography alterations at rest or during effort. In conclusion, this work suggests that physical effort to exhaustion is not a seizure-induced component.

Omega-3 consumption and sudden cardiac death in schizophrenia

People with schizophrenia show a two- to three-fold increased risk to die prematurely. Mortality is accounted for by a combination of factors (patients' life style, suicide, premature cardiovascular disease, metabolic syndromes and, not so often mentioned, sudden death). The cause of sudden death in schizophrenia is unknown, but cardiac arrhythmia plays a potential role. Patients with schizophrenia are at high risk for cardiovascular disease, and some antipsychotics may be associated with cardiovascular adverse events (e.g., electrocardiograph QT interval prolongation), suggesting that this could lead to sudden cardiac death. Animal and clinical studies have shown that omega-3 fatty acids could be useful in the prevention and treatment of schizophrenia. As omega-3 fatty acids have been considered a cardioprotector agent, reducing cardiac arrhythmias and hence sudden cardiac deaths and given their relative safety and general health benefits, our update article summarizes the knowledge by the possible positive effects of omega-3 supplementation and fish consumption against sudden cardiac death in patients with schizophrenia. However, fish species should be selected with caution due to contamination with toxic methylmercury.

Benefits of sunlight: vitamin D deficiency might increase the risk of sudden unexpected death in epilepsy

Epilepsy is the most common serious neurological condition and sudden unexpected death in epilepsy (SUDEP) is the most important direct epilepsy-related cause of death. Information concerning risk factors for SUDEP is conflicting, but high seizure frequency is a potential risk factor. Additionally, potential pathomechanisms for SUDEP are unknown, but it is very probable that cardiac arrhythmias during and between seizures or transmission of epileptic activity to the heart via the autonomic nervous system potentially play a role. In parallel, studies have shown a link between vitamin D dysfunction and epilepsy. Moreover, several evidences in the literature suggest an association between low vitamin D and seizures, indicating the possibility of anticonvulsant properties of this hormone. Quite interesting, a growing body of data suggests that low vitamin D levels may adversely affect cardiovascular health, directly associated with death from heart failure and sudden cardiac death. In view of the above findings, our research group focused in this review article that SUDEP, at least in some cases, could be related with low vitamin D levels.

Physical activity in sudden unexpected death in epilepsy: much more than a simple sport

Sudden unexpected death in epilepsy (SUDEP) is the most important direct epilepsy-related cause of death. Additionally, potential pathomechanisms for SUDEP is unknown, but it is very probable that cardiac arrhythmia during and between seizures, electrolyte disturbances, arrhythmogenic drugs or transmission of epileptic activity via the autonomic nervous system to the heart may play a potential role. Quite interestingly, clinical and experimental data have shown that physical activity can decrease seizure frequency, as well as lead to improved cardiovascular health in patients with epilepsy. Based on these facts, the purpose of this article is to review the body of literature of the possible contribution of physical exercise to the SUDEP prevention in a comprehensive manner.

Assessing the link between omega-3 fatty acids, cardiac arrest, and sudden unexpected death in epilepsy

People with epilepsy may have abnormal cardiac function. This has been linked to a greater incidence of sudden unexpected death in epilepsy (SUDEP). In the present review, we assess the evidence linking cardiac failure to SUDEP, and propose the use of the maximal pentylenetetrazol seizure test to model SUDEP in animals to identify causal links between cardiac failure and SUDEP. We also discuss recent claims on the use of omega-3 polyunsaturated fatty acids to reduce the incidence of SUDEP because of their cardioprotective and anticonvulsant effects.