Benign Convulsions with Mild Gastroenteritis—An Underestimated Phenomenon?

Older Patients May Have More Frequent Seizures among Children Diagnosed as Benign Convulsions with Mild Gastroenteritis

How often do you diagnose benign convulsions with mild gastroenteritis (CwG) in your patients? In Europe, we rarely consider this entity. Though cases in all ethnicities have been described, CwG predominantly affects children with East Asian ethnicity, with large case series published since its first description in 1982 by Morooka in Japan.[1] The condition is clinically characterized by convulsions accompanying symptoms of mild diarrhea without moderate to severe dehydration, without electrolyte imbalance, without hypoglycemia, and without fever before and after the seizure in a previously healthy infant or child. Meningitis and encephalitis also need to be ruled out.[2] [3] No single underlying infectious agent has been identified, CwG can complicate gastroenteritis caused by rotavirus, norovirus, or other viruses. In a few patients, focal epileptiform discharges have been described on interictal electroencephalogram.[4] Recurrent seizures frequently are observed during the acute illness,[1] while follow-up shows no increased risk for development of epilepsy. As yet, no underlying genetic factors or consistently associated biomarkers have been found, though recently elevated uric acid has been described in some patients.[5] If patients suffer repeated seizures during a gastroenteritis, antiseizure medication may be indicated. In a small cohort, possible efficacy of phenobarbital to prevent further seizures has recently been demonstrated.[6]

In this issue, Su Jeong You reports on a large cohort of infants and young children between 1 month and 6 years of age presenting with benign CwG.[7] In her retrospective analysis, she only included patients strictly fulfilling diagnostic criteria, and excluded patients with a nonbenign course, especially those developing epilepsy or showing further seizures independent from gastroenteritis. While almost half of the patients suffered only one seizure, repeated seizures also were common. When comparing patients having one or two seizures only with those having three or more, she found that older patients were significantly more prone to experience frequent seizures. Older patients also were more likely to receive antiseizure medication during the acute illness. She speculates that factors associated with brain maturation and neuroinflammation may be responsible for the apparently more severe course in children beyond the age of 20 months.

CwG clearly are distinct from febrile seizures. In a cohort of children with rotavirus gastroenteritis, duration of gastrointestinal symptoms before seizure onset was longer in those suffering afebrile seizures, that is, CwG, in comparison to those suffering febrile seizures. This points to a possible role of immunological or other humoral factors facilitating convulsions that still need to be elucidated. Verrotti et al suggest considering CwG as “situation-related seizures due to an acute and transient brain dysfunction caused only by factors related to viral gastroenteritis.”[8]

Follow-up studies have shown that development of epilepsy following CwG is rare, though in an Italian case series, 17.3% of patients received antiseizure medication for a median period of 38 months.[8] Still, none of the children in their cohort developed epilepsy.

Benign CwG is a differential diagnosis in infants and young children presenting with single seizures or clusters during a gastroenteritis. Before assuming such benign condition, however, serious underlying or accompanying disorders need to be ruled out. While antiseizure medication may be required during the acute illness for prolonged or repeated seizures, there is no rationale to maintain a patient on antiseizure medication following resolution of gastroenteritis and seizures. Recognizing CwG may help to prevent overtreatment of infants and young children.

Publication History

Article published online:
20 August 2020

• References

• 1 Morooka K. Convulsions and mild diarrhea [in Japanese]. Shonika (Tokyo) 1982; 23: 131-137
• 2 Komori H, Wada M, Eto M, Oki H, Aida K, Fujimoto T. Benign convulsions with mild gastroenteritis: a report of 10 recent cases detailing clinical varieties. Brain Dev 1995; 17 (05) 334-337
• 3 Verrotti A, Tocco AM, Coppola GG, Altobelli E, Chiarelli F. Afebrile benign convulsions with mild gastroenteritis: a new entity?. Acta Neurol Scand 2009; 120 (02) 73-79
• 4 Kang B, Kim DH, Hong YJ, Son BK, Kim DW, Kwon YS. Comparison between febrile and afebrile seizures associated with mild rotavirus gastroenteritis. Seizure 2013; 22 (07) 560-564
• 5 Yoo IH, Kim W, Cho J. , et al. Elevated serum uric acid in benign convulsions with mild gastroenteritis in children. J Clin Neurol 2019; 15 (04) 496-501
• 6 Takami Y, Nakagawa T. Efficacy of phenobarbital for benign convulsions with mild gastroenteritis: a randomized, placebo-controlled trial. Brain Dev 2019; 41 (07) 600-603
• 7 You SJ. Older patients may have more frequent seizures among children diagnosed as benign convulsions with mild gastroenteritis. Neuropediatrics 2020; DOI: 10.1055/s-0040-1701442.
• 8 Verrotti A, Moavero R, Vigevano F. , et al. Long-term follow-up in children with benign convulsions associated with gastroenteritis. Eur J Paediatr Neurol 2014; 18: 572-577