Clinical neurophysiology and cerebrospinal liquor analysis to detect Guillain-Barré syndrome and polyneuritis cranialis in COVID-19 patients: A case series.

We report a case series of five patients affected by SARS-CoV-2 who developed neurological symptoms, mainly expressing as polyradiculoneuritis and cranial polyneuritis in the 2 months of COVID-19 pandemic in a city in the northeast of Italy. A diagnosis of Guillain-Barré syndrome was made on the basis of clinical presentation, cerebrospinal fluid analysis, and electroneurography. In four of them, the therapeutic approach included the administration of intravenous immunoglobulin (0.4 g/kg for 5 days), which resulted in the improvement of neurological symptoms. Clinical neurophysiology revealed the presence of conduction block, absence of F waves, and in two cases a significant decrease in amplitude of compound motor action potential compound muscle action potential (cMAP). Four patients presented a mild facial nerve involvement limited to the muscles of the lower face, with sparing of the forehead muscles associated to ageusia. In one patient, taste assessment showed right-sided ageusia of the tongue, ipsilateral to the mild facial palsy. In three patients we observed albuminocytological dissociation in the cerebrospinal fluid, and notably, we found an increase of inflammatory mediators such as the interleukin-8. Peripheral nervous system involvement after infection with COVID-19 is possible and may include several signs that may be successfully treated with immunoglobulin therapy.