SARS-CoV-2 associated acute, motor and sensory, axonal neuropathy requires comprehensive diagnostic work-up.

Abstract

We have read with interest the article by AlTahan et al1 on a 25 years-old female who was diagnosed with sensori-motor Guillain-Barre syndrome (GBS) with onset 14 days after a mild SARS-CoV-2 infection.1 Based on the predominance of sensory disturbances and reduced amplitudes of compound muscle action potentials (CMAPs) and of sensory nerve action potentials (SNAPs), GBS was sub-classified as acute, motor, sensory, and axonal neuropathy (AMSAN).1 The patient profited significantly from intravenous immunoglobulins (IVIGs) and gabapentin (GBT).1 The study is excellent but has limitations that raise concerns and should be discussed. A limitation of the study is that no magnetic resonance imaging of the cranial nerve roots with contrast medium was carried out.1 Because the patient complained about pain in the face and the tongue, it is crucial that nerve roots of cranial nerves V, IX, and X were investigated. In GBS with cranial nerve involvement, thickening or enhancement of cranial nerve roots has been reported.2 To rule out Bickerstaff encephalitis, a rare subtype of GBS,3 and other types of encephalitis, it is crucial that also an MRI of the brain with contrast medium is carried out. Another limitation of the study is that cerebrospinal fluid (CSF) examinations were not comprehensive. There is no mention of oligoclonal bands (OCBs), which can be positive in SARS-CoV-2 associated GBS. To rule out infectious radiculitis it is crucial to examine the CSF for bacterial, viral, fungal, and parasitic infection by appropriate tests. There is also no mention of cytokine and chemokines levels in the CFS which are usually elevated in SARS-CoV-2 associated GBS.4 Distal latencies were markedly prolonged in the median nerve (8.6 ms), ulnar nerve (5.5 ms), peroneal nerve (10 ms).1 Surprisingly, F-wave latencies were reported as normal.1 One would expect prolonged F-wave latencies if distal latencies are markedly prolonged. How do the authors explain this discrepancy? There is no mention whether distal quadruparesis resolved in addition to sensory disturbances upon IVIGs. Because resolution of facial, tongue and limb sensory disturbances could be also due to GBT, it is crucial Correspondence