A Case of Intractable Hypophosphatemia in a Patient with Guillain-Barré Syndrome and Encephalitis after SARS-CoV-2 Infection

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection attacks the respiratory and nervous systems. Among patients with SARS-CoV-2 infection, cases with simultaneous central and peripheral nervous system damage are rare, and those with intractable hypophosphatemia and hypokalemia complicating the former have not been reported yet. Case Presentation: A 59-year-old woman presented to the emergency department with incoherent speech evolving for 3 days. She had tested positive for the SARS-CoV-2 RT-PCR assay 8 days earlier. Her physical examination showed progressive limb weakness with diminished tendon reflexes and normal sensory examination. Cranial MRI revealed multiple abnormal signals in the brain. Cerebrospinal fluid (CSF) analysis and electromyography revealed acute motor axonal neuropathy (AMAN), further diagnosed as encephalitis combined with Guillain.Barré syndrome (GBS). The patient received glucocorticoid therapy, intravenous immune globulin (IVIG), and rehabilitation therapy. The patient experienced an intractable hypophosphatemia and hypokalemia during the treatment period, which was not effectively corrected several times. The symptoms improved after 1 month of treatment. Conclusion: Early diagnosis is important for the management of Guillain-Barré syndrome associated with SARS-CoV-2 infection. Moreover, in order to prevent life-threatening long-term persistent electrolyte disturbances in non-seriously ill patients, clinicians should pay particular attention to their electrolyte status.