What is S.U.D.E.P. ?
“Sudden, unexpected, witnessed or unwitnessed, nontraumatic and nondrowning death in patients with epilepsy, with or without evidence for a seizure and excluding documented status epilepticus, in which postmortem examination does not reveal a toxicologic or anatomic cause for death.”
SUDEP definition per Nashef 1997
What causes SUDEP?
The precise mechanism, or cause, of death is, as yet, not understood. Most sudden deaths of people with epilepsy are unwitnessed and this makes it difficult to determine what, exactly, occurs in the last moments of life. By definition, the post mortem does not reveal a cause of death suggesting that the terminal event is due to disturbance of function, not structure. Most frequently, but not always, there is evidence for seizure activity prior to death and recent studies strongly support a close relationship between seizure episodes (especially generalized convulsions) and SUDEP.
Various potential mechanisms have been proposed and these mainly involve the cardiac and/or respiratory systems. It is unknown whether mechanisms are jointly or severally responsible, what leads to the fatal cardiac event and/or the cessation of breathing, what role the brain and/or seizure plays in the whole process or, indeed, whether the same events trigger SUDEP in each person.
Risk factors for SUDEP
Without a known cause, it is not feasible to accurately determine whether or not an individual may be predisposed to SUDEP. However, investigations of SUDEP circumstances have identified several associated, or contributory, factors that indicate some individuals are at higher risk.
The factors most consistently identified in case studies include those which are deemed unmodifiable, such as early onset of epilepsy and young adult age, and those which are deemed modifiable with the potential to lower SUDEP risk. These include, but are not limited to, frequent generalized tonic-clonic seizures, poor compliance with the anti-epileptic drug (AED) regime and the number of different types of AEDs used.
What is the incidence of SUDEP?
SUDEP is estimated to account for up to 18% of all deaths in patients with epilepsy.
Consistent, and comparable, data on the incidence of SUDEP and its risk factors is proving difficult to ascertain. This is due to differences in research methodologies (including, definition of SUDEP, study type and reference populations) and inevitable methodological limitations. Most studies are restricted to smaller sample sizes and select epilepsy groups (such as tertiary care clinics or residential homes) because of the relatively rare incidence of SUDEP in the population and the impracticality of studying large numbers of individuals with epilepsy from diagnosis to death.
The alternative research approach, conducting retrospective studies of those identified as having died from SUDEP, is hampered by the apparent underuse of the term SUDEP as a cause of death on death certificates, as found in the UK (Langan et al 2002) and the USA (Schraeder et al 2006). Instead, the cause may be registered as, for example, ‘respiratory failure’ or ‘unascertained’ and would thereby be erroneously excluded from SUDEP case studies or statistics.
SUDEP definition per Nashef 1997
What causes SUDEP?
The precise mechanism, or cause, of death is, as yet, not understood. Most sudden deaths of people with epilepsy are unwitnessed and this makes it difficult to determine what, exactly, occurs in the last moments of life. By definition, the post mortem does not reveal a cause of death suggesting that the terminal event is due to disturbance of function, not structure. Most frequently, but not always, there is evidence for seizure activity prior to death and recent studies strongly support a close relationship between seizure episodes (especially generalized convulsions) and SUDEP.
Various potential mechanisms have been proposed and these mainly involve the cardiac and/or respiratory systems. It is unknown whether mechanisms are jointly or severally responsible, what leads to the fatal cardiac event and/or the cessation of breathing, what role the brain and/or seizure plays in the whole process or, indeed, whether the same events trigger SUDEP in each person.
Risk factors for SUDEP
Without a known cause, it is not feasible to accurately determine whether or not an individual may be predisposed to SUDEP. However, investigations of SUDEP circumstances have identified several associated, or contributory, factors that indicate some individuals are at higher risk.
The factors most consistently identified in case studies include those which are deemed unmodifiable, such as early onset of epilepsy and young adult age, and those which are deemed modifiable with the potential to lower SUDEP risk. These include, but are not limited to, frequent generalized tonic-clonic seizures, poor compliance with the anti-epileptic drug (AED) regime and the number of different types of AEDs used.
What is the incidence of SUDEP?
SUDEP is estimated to account for up to 18% of all deaths in patients with epilepsy.
Consistent, and comparable, data on the incidence of SUDEP and its risk factors is proving difficult to ascertain. This is due to differences in research methodologies (including, definition of SUDEP, study type and reference populations) and inevitable methodological limitations. Most studies are restricted to smaller sample sizes and select epilepsy groups (such as tertiary care clinics or residential homes) because of the relatively rare incidence of SUDEP in the population and the impracticality of studying large numbers of individuals with epilepsy from diagnosis to death.
The alternative research approach, conducting retrospective studies of those identified as having died from SUDEP, is hampered by the apparent underuse of the term SUDEP as a cause of death on death certificates, as found in the UK (Langan et al 2002) and the USA (Schraeder et al 2006). Instead, the cause may be registered as, for example, ‘respiratory failure’ or ‘unascertained’ and would thereby be erroneously excluded from SUDEP case studies or statistics.
