Burden of Illness

Explore the new 2017 ILAE classification, prevalence, economic impact, response rates to AED therapy, and non-adherence considerations for epilepsy.

Key Reasons for Revision of Epilepsy Classification1

  • The International League Against Epilepsy (ILAE) revised its classification of seizure types to be operational rather than based on fundamental mechanisms
  • Reasons for the revision include:
    • clarity of nomenclature
    • ability to classify some seizure types as either focal or generalized
    • classification when onset is unknown
  • Seizures are divided into: focal, generalized, unknown onset, with subcategories of motor, non-motor, with retained or impaired awareness for focal seizures

Changes from the 1981 Classification (extended in 2010)1

(1) “partial” becomes “focal”;
(2) awareness is used as a classifier of focal seizures;
(3) the terms dyscognitive, simple partial, complex partial, psychic, and secondarily generalized are eliminated;
(4) new focal seizure types include automatisms, behavior arrest, hyperkinetic, autonomic, cognitive, and emotional;
(5) atonic, clonic, epileptic spasms, myoclonic, and tonic seizures can be of either focal or generalized onset;
(6) certain seizure types can be either focal, generalized or unknown onset;
(7) new generalized seizure types are absence with eyelid myoclonia, myoclonic absence, myoclonic–atonic, myoclonic–tonic–clonic; and
(8) seizures of unknown onset may have features that can still be classified.

The new classification does not create fundamental changes, but allows greater flexibility and transparency in naming types of seizures.

Burden of Epilepsy in the US Population

  • 1.8% of US adults (4.3 million people) have epilepsy2
    • ~200,000 new diagnoses of epilepsy occur annually3
    • 1 in 26 people will develop epilepsy at some point in their lives4
  • Incidence is highest in the very young and in older adults3
    • Nearly 25% of diagnoses in children are in those less than 15 years old3
    • Epilepsy is the 5th most common neurological condition in nursing home residents5
  • Epilepsy contributes to significantly poorer health-related quality of life and higher rates of comorbidities than general population3
    • More likely to suffer from respiratory diseases, hypercholesterolemia, heart disease, arthritis, and cancer3
  • Approximately 1.38% of veterans have epilepsy, with most having focal type, compared to .5% in the general population6

Estimated annual total indirect and direct cost of epilepsy in the US7

Economic Burden of Partial-Onset Seizures (POS) — Refractory vs Non-refractory Epilepsy Patients8

Average annual POS-related direct health care costs in 2008 for refractory* vs non-refractory epilepsy patients (N=41,640)

Study design: The study objective was to assess economic burden in direct health care utilization and costs for refractory epileptic patients with partial-onset seizures (POS) and assess AED treatment patterns among these patients. Costs were determined from a retrospective study of administrative claims of the Thomson Medstat Marketscan Commercial Insurance Database from 2004–2008. This database includes ~30 million commercially insured individuals from ~100 payers.

*Refractory defined as patients with ≥3 antiepileptic drugs.

In a Long-term Non-interventional Prospective Study,* Despite Trying Multiple Agents, 36% of Patients Had Seizures That Were Uncontrolled With 2 or More AEDs9

Response Rates to AED Therapy in Patients with Previously Untreated Epilepsy

Study design: 525 patients (age, 9 to 93 years) who were given a diagnosis, treated, and followed up at a single center between 1984 and 1997 were prospectively studied. Epilepsy was classified as idiopathic (with a presumed genetic basis), symptomatic (resulting from a structural abnormality), or cryptogenic (resulting from an unknown underlying cause). Drug doses were adjusted as clinical circumstances dictated, with particular attention paid to efficacy and tolerability. Patients were treated with a single drug when possible, as is recommended practice. Treatment was changed to another drug if seizures remained uncontrolled or if the patient had an idiosyncratic reaction or intolerable side effects. A combination of drugs was used in patients whose epilepsy remained uncontrolled despite treatment with 2 or 3 single drugs.9

AED=antiepileptic drug.

*These data are generally accepted and have been replicated in multiple studies, including Brodie MJ, et al.10 Patients were considered to be seizure free if they had not had any seizures for at least 1 year.9

Many factors can influence AED nonadherence

Increasing Complexity of Dosing Regimens11,12
  • Polytherapy
  • Pill burden
  • Misunderstanding instructions
  • Anxiety and confusion over regimen
Limited Access to Medications12
  • Inability to drive
  • Lack of time to obtain medications
  • Inadequate or nonexistent reimbursement by health insurance plans
Poor education12
  • Lack of instructions on how to use medications
  • Lack of information about disease
  • Poor understanding of reasons for medication
Medical Factors12
  • Cognitive effects of seizures
  • Comorbid conditions
  • Memory loss due to brain damage and forgetfulness
  • Medication adverse effects
Psychosocial Factors12
  • Weak emotional support
  • Poor relationship with health care provider
  • Fear of addiction or adverse effects
  • Denial of disease

Strategies for Improving Compliance13

In January 2011, the American Academy of Neurology published guidelines for quality improvement in follow-up visits for diagnosed epilepsy patients. The aim of these guidelines was to improve patient care in adult and pediatric epilepsy by improving consistency in follow-up care, including documentation.13

American Academy of Neurological Epilepsy Measures
Quality measure Review frequency
Seizure type and current seizure frequency All visits
Documentation of etiology of epilepsy or epilepsy syndrome All visits
EEG results reviewed, requested, or ordered Initial visit or if not done
MRI/CT scan reviewed, requested, or ordered Initial visit or if not done
Querying and counseling about antiepileptic drug side effects All visits
Surgical therapy referral consideration for intractable epilepsy Intractable patients every 3 years
Counseling about epilepsy specific safety issues Annually
Counseling for women of childbearing potential with epilepsy Annually

CT = computed tomography; EEG = electroencephalography; MRI = magnetic resonance imaging.

The authors of one study on children performed a quality improvement project aimed at increasing compliance with these guidelines after educating physicians about them. The authors performed a chart review before and after an intervention which included:

  • education regarding the guidelines
  • providing materials to remind providers of the guidelines
  • templates to facilitate compliance

Charts were reviewed at 2 and 6 months after the educational intervention, which showed significant improvement in documentation of 4 of the 8 measures - etiology of seizures identified or idiopathic, discussion of side effects of AEDs, seizure safety issues discussed, and imaging of brain documented. There was no significant improvement in documentation of EEG findings, discussion of pregnancy-related complications in epilepsy, or documentation of seizure frequency. However, the documentation most frequently reflected lack of seizure description, not frequency.13

Furthermore, a similar study in adults, regarding the assessment and appropriate recording of clinical data for each visit, found an improvement in the documentation of all quality measures after the implementation of a new worksheet.14



  1. Epilepsy Foundation. 2017 Revised Classification of Seizures. www.epilepsy.com/article/2016/12/2017-revised-classification-seizures. Accessed October 2, 2017.
  2. Epilepsy Fast Facts. Centers for Disease Control Prevention (CDC) website. Available at http://www.cdc.gov/epilepsy/basics/fast-facts.htm
  3. Cardarelli WJ, Smith, BJ. The Burden of Epilepsy to Patients and Payers. http://www.ajmc.com/journals/supplement/2010/a324_10dec_epilepsy/a324_10dec_cardarelli_s331to336.
  4. England MJ, Liverman CT, Schultz AM, et al, eds. Epilepsy Across the Spectrum: Promoting health and understanding. Washington, DC: National Academies Press; 2012.
  5. Birnbaum AK, Leppik IE, Svendsen K, et al. Prevalence of epilepsy/seizures s a comorbidity of neurologic disorders in nursing homes. Neurology. 2017;88(8):1-8.
  6. Boyle A. Epilepsy Centers of Excellence provide options for veterans with drug-resistant epilepsy. http://www.usmedicine.com/clinical-topics/neurology/epilepsy-centers-of-excellence-provide-options-for-veterans-with-drug-resistant-epilepsy/. Accessed April 20, 2017.
  7. Centers for Disease Control and Prevention. Epilepsy Fast Facts. www.cdc.gov/epilepsy/basics/fast-facts.htm. Accessed October 2, 2017.
  8. Chen SY, Wu N, Boulanger L, Sacco P. J Med Econ. 2013;16(2):240-248.
  9. Kwan P, et al. N Engl J Med. 2000;342(5):314-319.
  10. Brodie MJ, et al. Neurology. 2012;78:1548-1554.
  11. Cramer JA, Glassman M, Rienzi V. The relationship between poor medication compliance and seizures. Epilepsy Behav. 2002;3:338-342.
  12. Wagner ML, Murad D, Patel D. Compliance in epilepsy: a review. US Pharm. 2001;26:33.
  13. Nelson et al. Educational Intervention Improves Compliance With AAN Guidelines for Return Epilepsy Visits: A Quality Improvement Project. J Child Neurol. 2016;31:1320-1323.
  14. Cisneros-Franco. Impact of the implementation of the AAN epilepsy quality measures on the medical records in a university hospital. BMC Neurol. 2013;13:112.