Premature mortality in people with epilepsy in China
[Part 4: Action; Ding D]
Up to 1% of people in the world have epilepsy, over 80% of whom live in developing countries. It is estimated that 9,000,000 people have epilepsy in China, increasing by 450,000 newly diagnosed patients annually. About two thirds of them do not receive regular treatment, mainly because of difficulties with the treatment infrastructure and the availability of suitable drugs. People with epilepsy have an increased risk of premature death compared with the general population.
The extent and nature of the premature mortality risk has not been sufficiently examined, especially in resource-poor countries. In China, only a few studies have described mortality rates of epilepsy in the general population, providing a range of 3–8 per 100,000 people per year (Department of Psychiatry, 1981; Li et al., 1985; Li et al., 1989 ) The case fatality rate estimated from national health statistics is 0.7% of in-patient cases (Chinese Ministry of Health, 2005).
In 1997, the World Health Organization (WHO), in cooperation with the International League against Epilepsy (ILAE) and the International Bureau for Epilepsy (IBE) launched the Global Campaign Against Epilepsy in an attempt to bring epilepsy “out of the shadows” and to improve the treatment of people with epilepsy in resource-poor countries. One such demonstration project, “Epilepsy Management at Primary Health Level” (EMPHL), under the auspices of the WHO and the Ministry of Health of China, was implemented in rural areas in six non-contiguous provinces of China (Wang et al., 2003). The EMPHL protocol used strict follow-up and management procedures to follow and assess mortality in people with epilepsy in rural China. During follow-up, local primary-care physicians recorded demographic data and putative cause of death of any patient who died. Cause of death was attributed on clinical grounds and verbal autopsy. Specialists and the principal investigators in each study area gathered information about cause of death through interviews with relatives or local village physicians. Death certificates were also used for confirmation of the cause of death (Ding et al., 2006).
By June 2004, the first follow-up wave (median follow-up time of 25 months) found 35 deaths among 2,455 people with epilepsy. Patients aged 15-29 years had 22 times higher mortality ratios than did those in other age-groups. The main cause of death was accidental or as a result of injury. In one third of patients, death was attributed to haemorrhagic or ischaemic stroke, whereas in two people death was attributed to pneumonia. In one patient death was attributed to sudden unexpected death in epilepsy (SUDEP) after a negative post-mortem examination (Ding et al., 2006). By December 2008, the second follow-up wave (median follow-up time of 6.1 years) found 206 deaths in the cohort with 1,986 people with epilepsy who were located. The main causes of death were cerebrovascular disease (15%), drowning (14%), self-inflicted injury (13%), and status epilepticus (6%), with probable SUDEP in 1%. The risk of premature death was 1.9 times greater in people with epilepsy than in the general population. A much higher risk of 28–37 times was found in young people. Duration of epilepsy and living in a waterside area were independent predictors for drowning (Ding et al., 2013).
There was another prospective study to determine the causes of death among 3,568 people with convulsive epilepsy in the rural area of Sichuan province in west China. One hundred and six deaths were found, thus the case fatality rate was 3% during a median of 28 months' follow-up (2005-2009). The risk of premature death is nearly 5 times higher in people with convulsive epilepsy than in the general population and especially high among young people. The main causes of death were for accidental death (59%) including almost half of drowning; probable SUDEP (15%); status epilepticus (7%), and neoplasm (7%). The risk of drowning was 82-fold higher in the cohort than the general population, probably because Sichuan has extensive water resources and people often live close to water (Mu et al., 2011).
Studies from developed countries suggest that SUDEP is responsible for up to 17% of deaths in epilepsy (Lhatoo & Sander, 2005). Data concerning SUDEP reported from resource-poor settings is less accurate, since postmortem examinations are the exception. The Sichuan study reported 15% of probable SUDEP during the 2-year follow up (Mu et al., 2011). In the second follow-up wave of the EMPHL study with a longer follow-up period, only 2 (1%) probable SUDEP cases were identified. Thirty deaths (15%) were assigned to cerebrovascular diseases, and 7 deaths (3%) from ischemic heart disease; some of which may well have been due to SUDEP. In addition, SUDEP may have been the cause of death in some of those ascribed to status epilepticus, or from unknown cause (Ding et al., 2013).
Compared to western countries, the clinical and pathological research of SUDEP has not been sufficiently examined in China. There was only one report of 7 SUDEP cases by Wang and colleagues (Wang et al., 2004). They found that all 7 patients died during generalized tonic clonic seizures; two in sleep. Four of them had agitation or fright before death. Besides having oedema of brain and lung, some of the deceased patients had a reduction of neurones and an increase of gliocytes. None of them were found to have neoplasms or injuries in the brain (Wang et al., 2004).
Further scientific research and education programs are urgently needed in China to face the challenge of premature death, especially SUDEP. These include improving the knowledge of SUDEP in physicians, trying to have more detailed verbal autopsies including descriptions of the death by witnesses that may provide more evidence, trying to have post-mortem examinations to determine the cause of death, and seeking appropriate interventions.
Institute of Neurology, Fu Dan University, China
How to cite:
Ding D. Premature mortality in people with epilepsy in China. In: Hanna J, Panelli R, Jeffs T, Chapman D, editors. Continuing the global conversation [online]. SUDEP Action, SUDEP Aware & Epilepsy Australia; 2014 [retrieved day/month/year]. Available from: www.sudepglobalconversation.com.