Re: First seizures in adults
This letter correctly mentions eclampsia as a cause of tonic-clonic seizure. In the First seizure article and accompanying table, only the most common causes of symptomatic seizure could be specifically mentioned.(1) Eclampsia is a rare cause of symptomatic first seizure (2) (structural/ metabolic seizure in the new terminology). (3) Many other rare causes of first seizure were also not discussed, such as auto-immune disorders, again with a unique management pathway.(4) Based on European incidence, there are approximately 42,000 “first seizures” in the United Kingdom per annum.(5) Recent estimates suggest approximately 314 cases of eclampsia annually (6) presenting as a first seizure (or status epilepticus). This means that approximately 0.7% of first seizures will be due to eclampsia.
The diagnosis of eclampsia is important and may be difficult. As the classical presentations of eclampsia are reduced by improved prenatal care, atypical presentations become proportionately more common.(7) The majority of presentations are antenatal and preterm, and thus presentation may be to non-maternity staff. As there are approximately 140 emergency departments in the United Kingdom,(8) an average of two patients with eclampsia will be seen annually in each (actually less as this figure assumes all patients attend emergency departments when in fact some will attend maternity units directly).
Pregnant women may have a first seizure for many other reasons other than eclampsia. There is a need to carefully evaluate the cause in all patients. Presumption of eclampsia delayed diagnosis of the actual cause In 41% of pregnant women in one study,(9) emphasising the importance of careful differential diagnosis.
1. Angus-Leppan H. First seizures in adults. BMJ. 2014;348:g2470.
2. Angeles DK. Proposal for revised clinical and electroencephalographic classification of epileptic seizures. Epilepsia. 1981;22489(501).
3. Berg AT, Berkovic SF, Brodie MJ, Buchhalter J, Cross JH, van Emde Boas W, et al. Revised terminology and concepts for organization of seizures and epilepsies: report of the ILAE Commission on Classification and Terminology, 2005-2009. Epilepsia. 2010;51(4):676-85.
4. Devinsky O, Schein A, Najjar S. Epilepsy associated with systemic autoimmune disorders. Epilepsy currents. 2013;13(2):62-8.
5. Jallon P, Goumaz M, Haenggeli C, Morabia A. Incidence of first epileptic seizures in the canton of Geneva, Switzerland. Epilepsia. 1997;38(5):547-52.
6. Knight M, Ukoss. Eclampsia in the United Kingdom 2005. BJOG. 2007;114(9):1072-8.
7. Douglas KA, Redman C. Eclampsia in the United Kingdom. BMJ. 1994;309(6966):1395-400.
8. Boseley S, Wintour P. NHS plan to concentrate specialist A&E expertise in fewer hospitals. Guardian 13 Nov 2013. www.theguardian.com/society/2013/nov/12/plan-a-and-e-crisis.
9. Witlin AG, Friedman SA, Egerman RS, Frangieh AY, Sibai BM. Cerebrovascular disorders complicating pregnancy—beyond eclampsia. American J Obstetrics and Gynecology. 1997;176(6):1139-48.
Competing interests: No competing interests