预后通常较好。[104]Cross JH. Fever and fever-related epilepsies. Epilepsia. 2012 Sep;53(suppl 4):3-8.https://www.doi.org/10.1111/j.1528-1167.2012.03608.xhttp://www.ncbi.nlm.nih.gov/pubmed/22946716?tool=bestpractice.com[105]Vestergaard M, Christensen J. Register-based studies on febrile seizures in Denmark. Brain Dev. 2009 May;31(5):372-7.http://www.ncbi.nlm.nih.gov/pubmed/19203855?tool=bestpractice.com
大约 30% 的患儿在随后的发热性疾病中,会出现热性惊厥复发。[99]Sadleir LG, Scheffer IE. Febrile seizures. BMJ. 2007 Feb 10;334(7588):307-11.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1796669/http://www.ncbi.nlm.nih.gov/pubmed/17289734?tool=bestpractice.com 多数复发出现在 2 年以内。 单纯性热性惊厥发作出现无热惊厥发作和癫痫发作的风险率在 5% 或 5% 以下。 但是,复杂性热性惊厥中癫痫的发生率则达 10%-20%。[106]Chungath M, Shorvon S. The mortality and morbidity of febrile seizures. Nat Clin Pract Neurol. 2008 Nov;4(11):610-21.http://www.ncbi.nlm.nih.gov/pubmed/18978801?tool=bestpractice.com 热性惊厥与意外的癫痫猝死无关。[106]Chungath M, Shorvon S. The mortality and morbidity of febrile seizures. Nat Clin Pract Neurol. 2008 Nov;4(11):610-21.http://www.ncbi.nlm.nih.gov/pubmed/18978801?tool=bestpractice.com[107]Holm IA, Poduri A, Crandall L, et al. Inheritance of febrile seizures in sudden unexplained death in toddlers. Pediatr Neurol. 2012 Apr;46(4):235-9.http://www.ncbi.nlm.nih.gov/pmc/articles/pmid/22490769/http://www.ncbi.nlm.nih.gov/pubmed/22490769?tool=bestpractice.com 流行病学数据表明绝大多数热性惊厥患儿长期预后正常。[5]Waruiru C, Appleton R. Febrile seizures: an update. Arch Dis Child. 2004 Aug;89(8):751-6.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1720014/http://www.ncbi.nlm.nih.gov/pubmed/15269077?tool=bestpractice.com[108]Knudsen FU. Febrile seizures: treatment and prognosis. Epilepsia. 2000 Jan;41(1):2-9.http://www.ncbi.nlm.nih.gov/pubmed/10643916?tool=bestpractice.com
遗传学研究表明,热性惊厥与随后的癫痫和神经认知功能障碍之间的关系有时是遗传性的,但遗传和环境因素之间存在着复杂的相互作用。[109]Huang CC, Chang YC. The long-term effects of febrile seizures on the hippocampal neuronal plasticity - clinical and experimental evidence. Brain Dev. 2009 May;31(5):383-7.http://www.ncbi.nlm.nih.gov/pubmed/19131199?tool=bestpractice.com
海马异常(颞叶内侧硬化)和局灶性癫痫可能与长时间热性惊厥发作有关。[67]Scott RC, King MD, Gadian DG, et al. Hippocampal abnormalities after prolonged febrile convulsion: a longitudinal MRI study. Brain. 2003 Nov;126(Pt 11):2551-7.http://www.ncbi.nlm.nih.gov/pubmed/12937081?tool=bestpractice.com 对单纯型热性惊厥的患儿,以及童年期有单纯性热性惊厥病史的成人,有报道指出磁共振成像检测到脑部异常。[110]Hesdorffer DC, Chan S, Tian H, et al. Are MRI-detected brain abnormalities associated with febrile seizure type? Epilepsia. 2008 May;49(5):765-71.http://onlinelibrary.wiley.com/doi/10.1111/j.1528-1167.2007.01459.x/fullhttp://www.ncbi.nlm.nih.gov/pubmed/18070090?tool=bestpractice.com[111]Auer T, Barsi P, Bone B, et al. History of simple febrile seizures is associated with hippocampal abnormalities in adults. Epilepsia. 2008 Sep;49(9):1562-9.http://onlinelibrary.wiley.com/doi/10.1111/j.1528-1167.2008.01679.x/fullhttp://www.ncbi.nlm.nih.gov/pubmed/18503555?tool=bestpractice.com 所以,热性惊厥的良性程度可能比普遍认为的要低。
有文献似乎支持发热状态对局灶性癫痫发生的作用,但发热状态本身在局灶性癫痫发生过程中显然既不是必要条件,也不是充分条件。对于存在热性癫痫持续状态的患儿,在以后的生活中可能需要多次损伤才会引发癫痫。[112]Ahmad S, Marsh ED. Febrile status epilepticus: current state of clinical and basic research. Semin Pediatr Neurol. 2010 Sep;17(3):150-4.http://www.ncbi.nlm.nih.gov/pubmed/20727483?tool=bestpractice.com