Clinically Mild Encephalopathy With a Reversible Splenial Lesion Type 2 Caused by Human Herpesvirus 6 Infection

• Published in: Pediatric neurology 2020-12, Vol.113, p.43-45
• Main Authors: Sano, Fumikazu, Fukao, Toshimichi, Tamaru, Kei, Kanemura, Hideaki, Inukai, Takeshi, Aihara, Masao
• Format: Article
• Language: English
• Subjects: Corpus callosum; Human herpesvirus 6; Magnetic resonance imaging; Mild encephalopathy with a reversible splenial lesion type 2
• ISSN: 0887-8994; 1873-5150
• DOI: 10.1016/j.pediatrneurol.2020.08.021

Clinically mild encephalopathy with a reversible splenial lesion (MERS) is the second commonest cause of encephalopathy. Several pathogens have been detected in patients with MERS type 2, such as influenza A and B, but little is known about the proportion of cases of MERS type 2 with this pathogenesis. Human herpesvirus 6 (HHV6) is the second commonest pathogen causing acute encephalopathy. However, HHV6 has not been previously reported in patients with MERS type 2. In this report, we describe a five-year-old boy with MERS type 2 caused by HHV6 infection. The present case was diagnosed with MERS type 2 caused by HHV6 infection based on the characteristic clinical course, the results of the virus testing, and imaging findings. This is the first description of MERS type 2 caused by HHV6 infection. Although there is a report of MERS type 1 caused by HHV6 infection, there are no detailed reports in the literature about MERS type 2 associated with HHV6 infection. Thus the clinical findings associated with MERS type 2 caused by HHV6 infection are poorly understood. This report indicates that HHV6 can cause MERS type 2.