Refractory epilepsy
Refractory epilepsy, affecting 20% of patients, doesn't respond to two tolerated antiseizure drugs. Diagnosis involves brain MRI and video-EEG monitoring. Resective epilepsy surgery is the main curative option, while other approaches offer palliative relief. Surgery is most effective when the focus is consistently identified. Further antiseizure drug treatment, selecting different drugs or combinations, and participating in clinical trials are alternative options for management.
2024-01-01 01:12:13 - Editor
Overview of Refractory Epilepsy (Drug-Resistant Epilepsy)
Refractory epilepsy, also known as drug-resistant epilepsy (DRE), is characterized by seizures that do not respond to two anti-seizure drug therapies, used either as monotherapy or in combination. Approximately 20% of epilepsy patients have DRE, which is linked to sudden unexplained death in epilepsy (SUDEP), disability, and reduced quality of life. Patients with DRE require thorough reevaluation to confirm epilepsy diagnosis and identify any underlying structural issues. Standard evaluations include brain MRI and video-EEG monitoring. (1, 2, 3)
Treatment Options for DRE
Resective Epilepsy Surgery
This is the primary curative option aimed at inducing remission. It is most effective for patients with consistent epileptic focus localization in EEG and other imaging modalities like MRI or brain SPECT. Surgery is considered for patients with consciousness-impairing seizures, seizures leading to injury, and disabling seizure activities. (4, 6)
Alternative Therapies
Options include continued antiseizure drug treatment, vagal nerve stimulation, deep brain stimulation (DBS), ketogenic diet, and other surgical treatments like hemispherectomy or corpus callosotomy. These are generally more palliative, focusing on improving the quality of life. (5)
Antiseizure Drug Treatment for DRE
Review and Adjustment
It's crucial to review prior treatments to ensure previous drug doses and frequencies were adequate. Selecting drugs with different mechanisms of action or drug combinations might improve outcomes. About 14% remission rates have been observed with this approach. (7)
Clinical Drug Trials
Enrollment in clinical drug trials for investigational antiseizure drugs is an option for patients who are not surgical candidates or prefer not to proceed with current therapy. (7)
Overall, managing DRE requires a comprehensive approach, including accurate diagnosis, appropriate treatment selection, and continuous evaluation and adjustment of therapeutic strategies.
References
1- Kwan P, Brodie MJ. Early identification of refractory epilepsy. New Engl J Med. 2000;342:314–9.
2- Berg AT, Langfitt J, Shinnar S, Vickrey BG, Sperling MR, Walczak T, et al. How long does it take for partial epilepsy to become intractable? Neurology. 2003;60:186–90.
3- Kwan P, Arzimanoglou A, Berg AT, Brodie MJ, Allen Hauser W, Mathern G, et al. Definition of drug resistant epilepsy: Consensus proposal by the ad hoc Task Force of the ILAE Commission on Therapeutic Strategies. Epilepsia. 2010;51:1069–77.
4- Radhakrishnan K, Fried I, Cascino GD. Lesionectomy: Management of substrate-directed epilepsies. In: Engel J Jr, Pedley TA, editors. Epilepsy: A Comprehensive Textbook. 2nd ed. Philadelphia: Lippincott-Raven; 2008. pp. 1891–906.
5- Roberts DW. Corpus callosotomy. In: Engel J Jr, Pedley TA,
editors. Epilepsy: A Comprehensive Textbook. 2nd ed. Philadelphia: Lippincott-Raven; 2008. pp. 1907–13.
6- Wiebe S, Blume WT, Girvin JP, Eliasziw M Effectiveness and Efficiency of Surgery for Temporal Lobe Epilepsy Study Group. A randomized, controlled trial of surgery for temporal lobe epilepsy. N Engl J Med. 2001;345:311–8.
7- Galanopoulou AS, Buckmaster PS, Staley KJ, Moshé SL, Perucca E, Engel J, Jr, et al. American Epilepsy Society Basic Science Committee And The International League Against Epilepsy Working Group On Recommendations For Preclinical Epilepsy Drug Discovery. Identification of new epilepsy treatments: Issues in preclinical methodology. Epilepsia. 2012;53:571–82.