Presumptive human herpesvirus 6 myelopathy in an immunocompetent patient

Excerpt

Human herpesvirus 6 (HHV-6) is a designation that includes two distinct herpesvirus variants HHV-6A and HHV-6B (Ablashi et al. 2014). The seroprevalence of HHV-6 approaches 100 % in humans. The vast majority of HHV-6 infections occurs between the ages of 6 and 12 months and is clinically characterized by exanthema subitum (roseola infantum or sixth disease) (Yamanishi et al. 1988). HHV-6 has been recognized as a cause of neurological disease in immunocompromised patients, such as those with AIDS (De Bolle et al. 2005) or following bone marrow transplant (Kawamura et al. 2012). Additionally, associations between HHV-6 infection and a variety of neurological disorders have been proposed, including multiple sclerosis (Rotola et al. 2004; Cirone et al. 2002; Alvarez-Lafuente et al. 2004; Alenda et al. 2014), encephalomyelitis (Denes et al. 2004; Pot et al. 2008; Portolani et al. 2006), posterior reversible encephalopathy (Kawamura et al. 2012), and mesial temporal lobe epilepsy (Donati et al. 2003). Both HHV-6A and HHV-6B are neurotropic, though HHV-6A is believed to be more often associated with clinically significant neurological involvement (Pot et al. 2008; Portolani et al. 2006; Ahlqvist et al. 2005) and such involvement can be seen in immunocompetent subjects. …