Clinical Significance of Human Metapneumovirus in Refractory Status Epilepticus and Encephalitis: Case Report and Review of the Literature

Abstract

Encephalitis is a complex neurological disease that is associated with significant morbidity and mortality, and the etiology of the disease is often not identified. Human metapneumovirus (hMPV) is a common cause of upper and lower respiratory tract infections in children. Few reports are available showing possible involvement of hMPV in development of neurologic complications. Here, we describe an infant, the youngest case in literature, with refractory status epilepticus and severe encephalitis in whom hMPV was detected in respiratory samples and review diagnostic workup of patient with encephalitis.

Neurologic Alterations Due to Respiratory Virus Infections

“…These three cases were discharged without apparent sequelae. The year 2015, the first reported case of a child with refractory status epilepticus—a non-responsive condition with a worse prognosis than commonly responsive status epilepticus—was described (Vehapoglu et al, 2015 ). The 4-month-old boy was received and eventually transported to pediatric ICU.…”

“…Eventually, seizures passed, and 25 days post-admission she was discharged. No evident sequelae were detected, though antiepileptic drugs were maintained for the following 6 months (Vehapoglu et al, 2015 ).…”

“…Nowadays, the interest in increasing the knowledge about the characteristics and mechanisms involved in their neurological manifestations has risen. Neurological abnormalities found in patients with severe respiratory illness have a spread spectrum of clinical signs, being the most reported seizures (Niizuma et al, 2014 ; Li et al, 2016 ), status epilepticus (Sweetman et al, 2005 ; Vehapoglu et al, 2015 ), encephalopathies (Antonucci and Fanos, 2005 ; Mizuguchi et al, 2007 ; Niizuma et al, 2014 ; Meijer et al, 2016 ) and encephalitis (Ng et al, 2001 ; Niizuma et al, 2014 ; Fok et al, 2015 ; Table 1 ). The effects of each respiratory virus mentioned above in the CNS infection will be discussed in detail later.…”

Modulation of Host Immunity by the Human Metapneumovirus

“…Very rarely, lower ARTIs caused by HMPV may be accompanied by a presentation of neurological symptoms, including attention and executive deficits, nonfebrile seizures, and ataxia (37). While only one case has been described for an adult, who was 47 years of age, most other cases have been reported for children ranging from 4 months to 5 years of age (37)(38)(39)(40)(41)(42)(43)(44)(45)(46). Three independent studies have associated HMPV with acute encephalopathies ranging from subcortical encephalitis to multifocal demyelinating encephalitis, which are very rare ailments resulting from complications due to HMPV respiratory infection (39,40,43).…”

“…Three independent studies have associated HMPV with acute encephalopathies ranging from subcortical encephalitis to multifocal demyelinating encephalitis, which are very rare ailments resulting from complications due to HMPV respiratory infection (39,40,43). Furthermore, a case of refractory status epilepticus and encephalitis in a 4-month-old infant who also presented an ARTI positive for HMPV but not for other common respiratory pathogens was recently reported (44). Importantly, seizures were accompanied by lymphocytic pleocytosis in the cerebrospinal fluid (CSF), suggesting that the activation of lymphocytes infiltrating the brain and ependyma may be an important pathogenic mechanism in these neuropathies.…”