Epilepsy Across the Spectrum Promoting Health and Understanding (2012) / Chapter Skim
Currently Skimming:
3 Epidemiology and Prevention
3 Epidemiology and Prevention
Pages 109-160
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From page 109... ...
Most cases of epilepsy result from unknown causes, but some cases with known causes -- such as neurocysticercosis and other brain infections, traumatic brain injury, and stroke -- could be avoided. Epilepsy is linked to numerous physi cal, neurological, mental health, and cognitive comorbidities, including heart disease, autism spectrum disorders, Alzheimer's disease, depression, anxiety, and learning and memory problems.
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From page 110... ...
. In looking forward, future advances in biomedical research hold the promise of greater understanding of epileptogenesis or possibly a cure; meanwhile, it may be possible to prevent some known causes of epilepsy, such as neurocysticercosis through education and sanitary measures, other brain infections through vaccines, traumatic brain injury (TBI)
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From page 111... ...
Some tertiary prevention efforts target the consequences of epilepsy (e.g., early identification of those who do not respond to seizure medications in order to identify options to prevent seizure recurrence) , whereas others focus on its comorbidities (e.g., screening and interventions to identify and manage depression in people with epilepsy, described in Chapter 4)
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From page 112... ...
. However, it is not known whether these trends will continue or if changes in the distribution of risk factors for epilepsy (discussed later)
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From page 113... ...
Army Traumatic Brain Injury Task Force, 2007) , and mild TBIs comprise approximately three-quarters of all TBI cases in OEF-OIF service members (Armed Forces Health Surveillance Center, 2012)
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From page 114... ...
. Because TBI among returning veterans may be associated with an increased risk for developing epilepsy, work to distinguish mild TBI from PTSD is crucial.
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From page 115... ...
Prevalence data encompass the number of newly diagnosed cases of epilepsy as well as cases of epilepsy that persist over time, which includes people with continued seizures and people who are in remission but who take seizure medications. Except for rapidly fatal conditions, prevalence is greater than incidence, because it accounts for the accumulation of cases over time.
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From page 116... ...
. While associations between SES and the etiology of epilepsy is one possible explanation for the association between SES and prevalence, existing treatment gaps may play a role as well, since people of lower SES are less likely to obtain seizure medications or to be under the care of a neurologist than people of higher SES (Begley et al., 2009)
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From page 117... ...
Differences in care for prevalent epilepsy were also observed in residents of Alabama and surrounding states, where blacks were 60 percent less likely than non-Hispanic whites to undergo epilepsy surgery after receiving electroencephalograph (EEG) monitoring as part of a surgical evaluation, an association that persisted after controlling for factors such as SES and medical insurance coverage (Burneo et al., 2005)
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From page 118... ...
. Other known causes are rarer but confer a strong risk for developing epilepsy: brain infections, such as meningitis, encephalitis, and neurocysticercosis; pre- and perinatal injury; intellectual disability; cerebral palsy; and autism spectrum disorders (Annegers et al., 1988; Bergamasco et al., 1984; Carpio et al., 1998; Nelson and Ellenberg, 1987; Rocca et al., 1987; Tuchman and Rapin, 2002; Van der Berg and Yerushalmy, 1969)
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From page 119... ...
Prevention efforts for stroke often target its established risk factors, which include hypertension, cigarette smoking, and insufficient physical activity (Sacco et al., 1999)
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From page 120... ...
Hispanics with active epi 6 Defined in this study as people who have ongoing seizures (within the last 5 years) or are currently taking seizure medications.
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From page 121... ...
While the risk for continued seizures is relatively lower in epilepsy of unknown etiology than in epilepsy due to structural or metabolic causes and early mortality is lower (Forsgren 9 For example, identified genes, such as SCN1A, are rare but confer a strong risk for develop ing epilepsy (Ferraro et al., 2006)
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From page 122... ...
. Although several risk factors for developing epilepsy of unknown etiology have been elucidated recently, including mental health conditions and migraine (Hesdorffer et al., 2004, 2006; Ludvigsson et al., 2006; Ottman and Lipton, 1994)
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From page 123... ...
In a population-based, cross-sectional study, the most common somatic comorbid conditions among adults with prevalent epilepsy were fractures, asthma, diabetes, ischemic heart disease, and heart failure (Gaitatzis et al., 2004a)
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From page 124... ...
124 EPILEPSY ACROSS THE SPECTRUM TABLE 3-1 Comorbid Conditions Associated with Epilepsy Category Condition Sources Somatic disorders • Fractures Babu et al., 2009; Coppola • Asthma and other pulmonary et al., 2009; Gaitatzis et al., conditions 2004a; Hesdorffer et al., • Diabetes 1996b; Nuyen et al., 2006; • Heart disease and heart failure Ottman et al., 2011 • Osteoarthritis, osteopenia, and osteoporosis • Fibromyalgia • High blood pressure • Anemia Neurological • Stroke Berg et al., 2011; Bolton et al., disorders • Alzheimer's disease 2011; Gaitatzis et al., 2004a; • Brain neoplasm Hauser et al., 1993; Ottman • Autism spectrum disorders et al., 2011; Wallace, 2001 • Cerebral palsy • Migraine • Chronic pain and neuropathic pain Mental health • Mood disorders (e.g., depression) Berg et al., 2011; D'Alessio conditions • Anxiety disorders et al., 2006; Davies et al., • Alcohol-related disorders 2003; Gaitatzis et al., 2004a,c; • Attention deficit hyperactivity Hesdorffer et al., 2000, 2004, disorders 2006, 2007; Qin et al., 2005; • Schizophrenia and psychotic Rodenburg et al., 2005 disorders • Personality disorders • Suicidality • Seizure-like events with a psychological basis Cognitive • Cognitive impairment Elger et al., 2004; Hermann disorders • Intellectual disability and Seidenberg, 2007; • Learning disability Sillanpää, 2004 • Memory dysfunction Infectious disease • Neurocysticercosis Annegers et al., 1988; Carpio • Meningitis et al., 1998; Rocca et al., 1987 • Encephalitis Infestations • Possibly onchocerciasis and Kabore et al., 1996; Nicoletti toxocariasis et al., 2002, 2007, 2008; Pion et al., 2009 Physical disabilities • Hearing and vision loss Murphy et al., 1995 Injuries • Accidents and injuries Tomson et al., 2004 Nutritional • Malnutrition Crepin et al., 2007; Daniels problems • Gastrointestinal bleeding et al., 2009; Gaitatzis et al., • Obesity 2004a SOURCE: Adapted from Thurman et al., 2011.
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From page 125... ...
Among children with epilepsy and without cognitive impairment, autism spectrum disorders occurred in 2.2 percent and being male was the only associated risk factor (Berg et al., 2011)
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From page 126... ...
. These studies suggest that at least part of the increased risk for epilepsy in autism spectrum disorders may reflect increasing brain damage, some of which may have a genetic basis.
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From page 127... ...
. In the 1970s, studies of mental health conditions in people with prevalent epilepsy became a topic of interest for researchers exploring the adverse effects of seizure medications (Trimble and Reynolds, 1976)
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From page 128... ...
Given current knowledge, it is possible that interventions can be developed for the comorbidity of depression and epilepsy. Rather than the burden associated with having epilepsy increasing the risk for depression, the above findings suggest that depression may lower the seizure threshold, leading to an increased risk for epilepsy and an increased risk for continued seizures.
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From page 129... ...
The Managing Epilepsy Well (MEW) Network12 is an important effort in the development of behavioral interventions for people with epilepsy and comorbid mental health conditions (see also Chapters 4 and 7)
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From page 130... ...
By 10 years of age, the cumulative probability of developing epilepsy is 8 percent for children with autism spectrum disorders only, compared to 27 percent for children with autism spectrum disorders and severe intellectual disability and 67 percent for children with autism spectrum disorders, severe intellectual disability, and cerebral palsy (Tuchman and Rapin, 2002)
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From page 131... ...
. An increased risk for SE appears to be associated with severe cognitive impairments, rather than SE being the cause of cognitive decline (Helmstaedter, 2007)
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From page 132... ...
. Research Gaps Currently, there is insufficient knowledge about cognitive impairment in epilepsy, including its timing, its prognosis, and to what extent refractory epilepsy causes cognitive decline over time (Hermann and Seidenberg, 2007)
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From page 133... ...
. OUTCOMES In addition to the seizures themselves, a number of negative health outcomes are possible for people with epilepsy, including poorer overall health status, impaired intellectual and physical functioning, a greater risk for accidents and injuries, and side effects from seizure medications and other treatments (Camfield and Camfield, 2007; Kobau et al., 2008; Tomson et al., 2004)
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From page 134... ...
. A study examining long-term outcomes of childhood epilepsy found that children were more likely to achieve at least 5 years of remission if they had epilepsy of unknown etiology, no previous febrile seizures, a 3-month remission in the first 6 months, and a fast response to seizure medications (Geerts et al., 2010)
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From page 135... ...
. This risk factor has been confirmed in a large multicenter European cohort study, where the risk of injury in children (ages 5 and older)
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From page 136... ...
, the absence of an increased risk for injury in this population of children with epilepsy but without cognitive impairment may reflect less severe and less frequent seizures. Next Steps for Prevention: Accidents and Injuries In combination, these studies suggest that prevention of accidents and injuries among people with epilepsy will be related to improving seizure control and avoiding, if possible, adverse effects of seizure medications, such as dizziness, which may themselves lead to injury.
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From page 137... ...
. Other epidemiologic studies also have found an increased fracture incidence associated with the use of seizure medications and an association between seizure medications and falls, themselves a common cause of fractures (Bohannon et al., 1999; Cummings et al., 1995; Ensrud et al., 2002)
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From page 138... ...
. Most deaths in people with a known underlying cause of their epilepsy occur due to the underlying cause, such as brain tumor or stroke (which are themselves associated with an increased risk for death)
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From page 139... ...
There is a significant underappreciation of mortality in epilepsy. –Linda Coughlin Brooks Sudden unexpected death in epilepsy As noted in Chapter 2, deaths categorized as SUDEP encompass nontraumatic, non-drowning-related deaths in people with epilepsy that may or may not be associated with a recent seizure, but are not due to SE (Nashef et al., 2012)
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From page 140... ...
, the strongest evidence from a meta-analysis of randomized placebo-controlled clinical trials suggests that it is the occurrence of seizures that drives an increased risk for SUDEP (Ryvlin et al., 2011) , not polytherapy as suggested in previous studies (Hesdorffer et al., 2011b; Nilsson et al., 1999; Walczak et al., 2001)
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From page 141... ...
If SUDEP is related to continued seizures as suggested above, then it would be important to aggressively treat people with continued seizures and to optimize compliance with seizure medications (Chapter 7) , as is done in randomized clinical trials.
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From page 142... ...
. Additionally, only two seizure medications had a statistically significant increased risk for suicidality, and small protective effects were observed for two others.
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From page 143... ...
. Among people with prevalent epilepsy, who by definition have ongoing seizures or are taking seizure medications, the perception of stigma has been associated with increased depression and poor health status, as well as poor quality of life (Baker, 2002; Jacoby and Baker, 2008; Kumari et al., 2009; Reisinger and DiIorio, 2009)
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From page 144... ...
In addition, progress in the prevention of other risk factors -- such as stroke, through targeted efforts to reduce risk factors, and brain infections such as meningitis, through sustained vaccination programs -- will likely result in fewer new cases of epilepsy. Further opportunities for primary prevention may come to light if epidemiologic studies identify other risk factors for epilepsies whose etiologies are currently unknown.
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From page 145... ...
2009. Newly diagnosed single unprovoked seizures and epilepsy in Stockholm, Swe den: First report from the Stockholm Incidence Registry of Epilepsy (SIRE)
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From page 146... ...
2008. Estimating the incidence of first unprovoked seizure and newly diagnosed epilepsy in the low-income urban community of northern Manhattan, New York City.
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From page 147... ...
2008. Disentangling mild traumatic brain injury and stress reactions.
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From page 148... ...
2009. Prevalence of autism spectrum disorders -- Autism and Developmental Disabili ties Monitoring Network, United States, 2006.
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From page 149... ...
2010. Early versus late remission in a cohort of patients with newly diagnosed epilepsy.
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From page 150... ...
2008. VA health care: Mild traumatic brain injury screening and evaluation implemented for OEF/OIF veterans, but challenges remain.
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From page 151... ...
2005. Subgroup analysis and covariate adjustment in randomized clinical trials of traumatic brain injury: A systematic review.
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From page 152... ...
2006. De pression and suicide attempt as risk factors for incident unprovoked seizures.
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From page 153... ...
2002. Systematic review and meta-analysis of incidence studies of epilepsy and unprovoked seizures.
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From page 154... ...
2003. Development of a longitudinal study of complications and functional outcomes after traumatic brain injury.
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From page 155... ...
1999. Risk factors for sudden unexpected death in epilepsy: A case-control study.
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From page 156... ...
2008. Risk of autism spectrum disorders after infantile spasms: A population-based study nested in a cohort with seizures in the first year of life.
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From page 157... ...
2009. Sudden unexpected death in epilepsy: Risk factors and potential pathomechanisms.
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From page 158... ...
2007. Magnesium sulfate for neuroprotection after traumatic brain injury: A randomised controlled trial.
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From page 159... ...
2001. Incidence and risk factors in sudden unexpected death in epilepsy: A prospective cohort study.
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