Abstract
Background We present a 25-year-old woman with a background history of Multiple sclerosis (MS) on Ocrelizumab who presented with symptoms of meningoencephalitis. She initially presented with a 2-day history of worsening occipital headache, neck stiffness and photophobia. She had symptoms of Hand Foot and Mouth disease (HFMD) 2 weeks prior to this presentation.
Investigation and treatment progress
The first CSF study performed was positive for enterovirus within the CSF. However, enterovirus DNA was negative in the second CSF PCR study and was only found to be positive when the study was repeated using a nested PCR technique.
MRI scans showed symmetrical FLAIR hyperintensities within both thalamus and a non-enhancing signal abnormality within the left splenium of the corpus callosum.
The use of IVIG was considered but was held off as the patient’s conditioned improved rapidly with supportive therapy.
Teaching Points
Cases of enterovirus encephalitis in adults have been reported among patients receiving other B cell depleting therapy such as rituximab but has never been described in patients on Ocrelizumab which is also a B cell depleting agent.
Unusual opportunistic infection should be considered in patients on B cell depleting therapies despite having a normal IgG level. Furthermore, more sensitive PCR techniques such as a double nested PCR may need to be employed to confirm the diagnosis of opportunistic infections.
