Author response: Miller Fisher syndrome and polyneuritis cranialis in COVID-19.

Abstract

We thank Drs. Ni and Xu for their letter on our study.1 We think that our 2 patients developed Miller Fisher syndrome and polyneuritis cranialis because of an aberrant immunologic response to COVID-19. As we previously commented in the article, oropharyngeal swab test for SARS-CoV-2 by qualitative real-time reverse transcriptase polymerase chain reaction (PCR) assay was positive in both patients and negative in the CSF. We did not examine the presence of antibodies for SARS-CoV-2 in CSF because that technique had not been validated. In the patient who acutely presented with Miller Fisher syndrome, CSF PCR for enterovirus, herpes simplex virus type 1 and 2, and varicella zoster virus were negative as well as CSF-VDRL test. On the other hand, in the patient with polyneuritis cranialis, these tests could not be performed because of the extreme circumstances of the University Hospital “Príncipe de Asturias,” Alcala de Henares, Madrid, at the peak of this pandemic. Notwithstanding, considering the temporal relationship, we feel that SARS-CoV-2 infection was responsible for the development of these 2 neurologic pictures.