Cardiological Factors On Sudden Unexpected Death In Epilepsy


Epilepsy is a group of neurological diseases characterized by epileptic seizures. Epileptic seizures are episodes that can vary from brief and nearly undetectable to long periods of vigorous shaking. Recently from the bits of research, the fact is coming in a picture that epileptic patients have a risk of unexpected death due to cardiological factors. This article entails the link between cardiological parameters and sudden death in Epilepsy. SUDEP is defined specifically as the sudden, unexpected, witnessed or unwitnessed, non-traumatic and non-drowning death in patients with epilepsy with or without evidence for a seizure, and excluding documented status epilepticus, in which post-mortem examination does not reveal a structural or toxicological cause for death.

This condition is referred as Sudden Unexpected death in epilepsy (SUDEP). The cause of SUDEP is not known. Observations in individual cases have suggested possible cardiogenic, pulmonary, and primary neurological etiologies. It may be that SUDEP is a heterogeneous condition. The vast majority of witnessed cases have been associated with a seizure, and the main risk factor is uncontrolled seizures, especially convulsions. Incidence: SUDEP causes between 2 and 18 percent of all deaths in patients with epilepsy. This proportion may be moderately higher in children, as high as 30 percent in one cohort study. The estimated rate of SUDEP is approximately 1000 person/year based on the studies which incorporated a small number of cases. The lifetime cumulative risk for SUDEP by age 40 has been estimated at 7 percent overall, or 12 percent in those with persistent epilepsy. The cumulative full lifetime risk has been estimated to be 35 percent Pathophysiology of SUDEP: There are several factors which are taken into consideration based on the different studies being carried out on sudden unexpected death in epilepsy.

While SUDEP is only rarely witnessed, most observations suggest that SUDEP occurs in the context of a seizure. No singular mechanism has been established, and multiple pathophysiologic factors may be involved, including cardiac arrhythmia, seizure-induced respiratory changes and pulmonary dysfunction, and neurogenic cardiorespiratory depression. The major factors are listed below Cardiogenic Factors Some indirect evidence suggests, cardiac arrhythmias and cardiovascular disease, may be involved some cases of SUDEP, some factors are described below Ictal bradycardia and asystole: Ictal Bradycardia and asystole can be observed and even asystole is observed in some patients with epilepsy.

There is a strong possibility that some cases of SUDEP can be explained by this phenomenon. However, the relationship between the ictal heart and SUDEP is not strongly established. But it is a noted that known cases of ictal bradycardia or asystole have an increased risk of SUDEP compared with those who do not have these features. The rate of bradycardia and asystole in patients with epilepsy is ambivalent One study monitored electrocardiogram using an implantable loop recorder for an average of 18 months in 19 months with refractory epilepsy. Four patients had bradycardia or periods of asystole, prompting subsequent pacemaker placement; three of these episodes occurred during a clinical. One more study reviewed the monitoring data on 1277 seizures on 69 patients identified 5 patients in whom ictal bradycardia occurred in 18 percent There was another study in which the ictal asystole was observed on a long term, EEG monitoring in 10 of 6825 patients (0.15%). This occurrence was not associated with cardiovascular risk factors or abnormal baseline ECG. Apparently, bradycardia and asystole in epilepsy patients are most commonly analyzed. There is a possibility that partial seizures are connected with ventricular tachyarrhythmias.

In one case study, a 51-year-old woman developed ictal ventricular tachycardia evolving into a ventricular fibrillation arrest acquiring resuscitation. Prolonged QT interval and Tachyarrhythmias The suggested mechanism in SUDEP is also characterized by Seizure-induced changes in the QT interval or autonomic instability, predisposing to the malignant arrhythmias. This mechanism is bolstered by the fact that some patients carry a pathogenic mutation in one of the genes associated with congenital long QT syndrome. Seizure-induced changes in the QT interval have been described, although their significance is not clear. A number of case series of combined EEG-ECG telemetry have noted prolongation of the QT interval during seizures in 12 to 23 percent of patients. This finding may be associated with potentially fatal ventricular arrhythmias. However, in a matched case-control study, a prolonged QT interval was not specifically associated with SUDEP Cardiovascular Disease A case-control study in Stockholm found a history of epilepsy is a risk factor for an acute myocardial dysfunction.

They tested 57 patients and found the correlation of the epileptic factors and cardiovascular disease. This supports the link of Epilepsy and cardiovascular disease. Respiratory Dysfunction Alternatively, ventilatory failure with ictal hypoxemia and hypercapnia from centrally-mediated apnea may underlie some cases of SUDEP; frank apnea is sometimes observed. There are many studies which provide the evidence of the clear link between the above-mentioned factors. The data suggested above clearly, mentions the link between the cardiological factors and Epilepsy. It is apparent to stay alerted while treating the Epileptic patients for SUDEP. The follow up with Epilepsy patients is helpful and monitoring the parameters mentioned above can be taken into a consideration while treating patients.