Background The long-term prognosis of seizures that begin in childhood is uncertain. Methods We prospectively studied 245 children from the catchment area of Turku University Hospital in Turku, Finland, who had active epilepsy diagnosed between 1961 and 1964. Sixty-eight patients (28 percent) had idiopathic seizures (presumed to have a genetic origin), 54 (22 percent) had cryptogenic seizures (occurring in otherwise normal persons with no clear cause), and 123 (50 percent) had remote symptomatic seizures (with no immediate cause but occurring in persons with a prior brain injury or a static encephalopathy). Results At the final follow-up in 1992, we had sufficient data on 220 patients (90 percent), 176 of whom were alive and 44 of whom had died; the remaining 25 had emigrated, could not be traced, or declined to participate. Thirty-nine patients who died were not free of seizures at the time of death, and 33 had remote symptomatic seizures. Among the surviving patients, 112 (64 percent) had been seizure-f...

Long-term prognosis of seizures with onset in childhood.

Although largely neglected in earlier literature, sudden unexpected death in epilepsy (SUDEP) is the most important epilepsy-related mode of death, and is the leading cause of death in people with chronic uncontrolled epilepsy. Research during the past two to three decades has shown that incidence varies substantially depending on the epilepsy population studied, ranging from 0.09 per 1000 patient-years in newly diagnosed patients to 9 per 1000 patient-years in candidates for epilepsy surgery. Risk profiles have been delineated in case-control studies. These and other studies indicate that SUDEP mainly occurs in the context of a generalised tonic-clonic seizure. However, it remains unclear why a seizure becomes fatal in a person that might have had many similar seizures in the past. Here, we review SUDEP rates, risk factors, triggers, and proposed mechanisms, and critically assess potential preventive strategies. Gaps in knowledge are discussed and ways forward are suggested.

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Sudden unexpected death in epilepsy: current knowledge and future directions.

Objective: To determine incidence of and risk factors for sudden unexpected death in epilepsy (SUDEP). Methods: Three epilepsy centers enrolled 4,578 patients and prospectively followed these patients for 16,463 patient-years. The cohort was screened for death annually. Deaths were investigated to determine whether SUDEP occurred. Potential risk factors were compared in SUDEP cases and in controls enrolled contemporaneously at the same center. Results: Incidence of SUDEP was 1.21/1,000 patient-years and was higher among women (1.45/1,000) than men (0.98/1,000). SUDEP accounted for 18% of all deaths. Occurrence of tonic-clonic seizures, treatment with more than two anticonvulsant medications, and full-scale IQ less than 70 were independent risk factors for SUDEP. The number of tonic-clonic seizures was a risk factor only in women. The presence of cerebral structural lesions and use of psychotropic drugs at the last visit were not risk factors for SUDEP in this cohort. Subtherapeutic anticonvulsant levels at the last visit were equally common in the two groups. No particular anticonvulsant appeared to be associated with SUDEP. Conclusions: These results support the idea that tonic-clonic seizures are an important proximate cause of SUDEP. This information creates a risk profile for SUDEP that may help direct preventative efforts.

Incidence and risk factors in sudden unexpected death in epilepsy: A prospective cohort study

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(98)05114-9.pdf

Risk factors for sudden unexpected death in epilepsy: a case control study

Population-based analysis of sudden cardiac death with and without left ventricular systolic dysfunction: two-year findings from the Oregon Sudden Unexpected Death Study.

Summary: To measure the incidence of sudden unexplained death in treated persons with epilepsy (SUDEP) and to identify risk factors for SUDEP, a cohort of 6,044 persons aged 15–49 years with more than four prescriptions for antiepileptic drugs (AEDs) was identified from the Saskatchewan Health prescription drug file. To exclude subjects whose sudden deaths (SUDs) might be misattributed to another chronic underlying disease, subjects with hospitalizations for cancer or heart problems were excluded. To exclude subjects without epilepsy, subjects with >2-year AED treatment followed by AED-free time and subjects receiving < 1 U/day were excluded. The final cohort consisted of 3,688 subjects. Follow-up was started at the first AED prescription listed in the prescription drug file and ended at the earliest of the following: age 50 years, death, or last registration in the Saskatchewan Health. For 153 of 163 deaths occurring in the cohort, copies of anonymized death certificates were obtained and copies of anonymized autopsy reports of potential SUDEP cases were examined. There were 18 definite/probable SUDs and 21 possible SUDEPs, yielding a minimum incidence of 0.54 SUDEP per 1,000 person-years and a maximum of 1.35 SUDEP per 1,000 person-years. SUDEP incidence increased with male sex, number of AEDs ever prescribed, and prescription of psychotropic drugs and was highest in males with a history of treatment with three or more AEDs and four or more psychotropic drug prescriptions. Poisson regression showed a 1.7-fold increase in risk of SUDEP for each increment in maximum number of AEDs administered, a likely surrogate for severity and persistence of seizures.

Thomas B. Cole

Papers

Cohort study of incidence of sudden unexplained death in persons with seizure disorder treated with antiepileptic drugs in Saskatchewan, Canada