Encephalitis in COVID-19 Patients

May 18, 2020 by Sam Bazzi

Encephalitis (inflammation of the brain) has now been associated with COVID-19 in several published case studies from around the world. This week’s blog post will focus on several of these encephalitis case studies.

Case Presentation: A male patient from Wuhan (age not provided in the article) presented with typical COVID-19 symptoms, including fever and shortness of breath. His disease progressed and he began to show signs of confusion and altered consciousness. At the time of presentation, he was found to have low white blood cell count with lymphopenia. CT of the head was normal, but chest CT revealed ground glass opacities typical of COVID-19 infection. The patient showed signs of meningeal irritation, including neck rigidity, Kernig and Brudzinski signs. His physicians performed a lumbar puncture to collect cerebrospinal fluid (CSF) and CSF pressure was elevated at 220 mmHg. CSF was tested for SARS-CoV-2 and was negative. His final diagnosis was encephalitis due to systemic SARS-CoV-2 infection (Ye, et al., 2020). The patient went on to recover fully by the time of his hospital discharge.

Case #2: Another case involves a 24-year-old male patient from Japan who first presented with headache, generalized fatigue, and fever. He was prescribed the influenza prophylactic drug, Laninamivir, and fever-reducing medications under the diagnosis of influenza. His symptoms worsened and another clinic conducted chest X-rays and blood tests, which were both negative. On day 9 post-onset of symptoms, he was found unconscious on the floor and was immediately taken to the hospital. During transport, he had a generalized seizur. He had a Glasgow coma scale of 6 and had neck stiffness on presentation to the ER. Blood work revealed an increased white cell count, decreased lymphocytes, and increased C-reactive protein. CT scans revealed no signs of brain edema, but chest CT showed ground glass opacity in the chest. Lumbar puncture revealed that CSF pressure was above 320 mmH2O. The patient was tested for SARS-CoV-2 via pharyngeal swab, which resulted as negative, but interestingly in this patient, the CSF was positive for SARS-CoV-2. MRI of the brain at 20 hours post admission demonstrated hyperintense signal within the right mesial temporal lobe and hippocampus as well as mid hippocampal atrophy and pan-paranasal sinusitis (Moriguchi, et al., 2020). The patient remained encephalopathic in the intensive care unit by day 15 of hospitalization and was treated for bacterial pneumonia. This case raises the question of whether temporal lobe/hippocampal injury was due to direct viral infection or post infectious autoimmune phenomenon.

These two clinical cases share some similarities – in both cases, the patients presented with symptoms of encephalitis: neck stiffness and altered consciousness in context of an upper respiratory infection and ground glass opacities on the CT chest, which are telltale signs of COVID-19.  There were also important differences in their presentation and outcomes. Only one of the patients with encephalitis had SARS-CoV-2 in the CSF, and the positive test was associated with a worse clinical outcome compared to the patient with negative SARS-CoV-2 CSF test.  Given these emerging clinical cases of SARS-CoV-2 associated encephalitis, it is important to monitor COVID-19 patients for neurological signs of encephalitis as well as to consider COVID-19 in patients who initially present with neurological symptoms that suggest meningitis/encephalitis. Prompt attention to the diagnosis of SARS-CoV-2 related encephalitis will hopefully facilitate prompt treatment and improved patient outcomes.

Written by: Sam Bazzi
Edited by: Jina Zhou and Esther Melamed
5/18/2020