Author response to the letter to the editor regarding “Headaches and lymphocytic pleocytosis after COVID-19 require the exclusion of encephalitis”

Bickerstaff encephalitis.Furthermore, the GQ1b antibodies were negative.The author mentioned that a cerebral lymphoma was not ruled out.The histological analysis of the post-mortem brain revealed T-lymphocytic infiltrates with perivascular predominance, primarily in the basal ganglia and brain stem in addition to an involvement of the cranial and peripheral nerves.There was no indication of lymphoid cells.In further analysis, T-cell clonality testing revealed no rearrangement of the T-cell receptor beta (TCRB) or gamma (TCRG) genes, indicating a polyclonal T-cell population.Furthermore, Epstein-Barr virus (EBV) in situ hybridisation was negative.In summary our findings are consistent with an immune associated disease.The author highlights an absence of sufficient description of comorbidities and the course of the disease.Apart from a weight loss of 3 kg over the last few months, there had been no occurrence of B -symptoms.Due to the word restrictions by the journal, we did not describe all pre-existing conditions and medications in detail.The patient, who had multiple underlying conditions, had recovered from the pulmonary symptoms of the previously diagnosed COVID-19 disease.However, based on our clinical assessment and the additional findings reported, we considered steroid therapy to be the most appropriate initial treatment for what was most likely an immune-mediated neuritis associated to SARS-CoV-2 infection.The patient remained stable and was able to walk with minimal assistance throughout, so there was no reason to escalate treatment until her sudden death.The atrial thrombus was diagnosed by echocardiography, and anticoagulation was performed with low molecular weight heparin.