Critical illness neuropathy in severe COVID-19: a case series.

Introduction: Neurological complications of SARS-CoV-2 disease have received growing attention, but only few studies have described to date clinical and neurophysiological findings in COVID patients during their stay in intensive care units (ICUs). Here, we neurophysiologically assessed the presence of either critical illness neuropathy (CIP) or myopathy (CIM) in ICU patients.
Materials and Methods: Patients underwent a neurophysiological assessment, including bilateral examination of the median, ulnar, deep peroneal and tibial motor nerves and of the median, ulnar, radial and sural sensory nerves. Needle electromyography (EMG) was performed for both distal and proximal muscles of the lower and upper limbs. In order to differentiate CIP from CIM, Direct Muscle Stimulation (DMS) was applied either to the deltoid or tibialis anterior muscles. Peak to peak amplitudes and onset latencies of the responses evoked by DMS (DMS _amp , DMS _lat ) or by motor nerve stimulation (MNS _amp , MNS _lat ) were compared. The ratio MNS _amp to DMS _amp (NMR) and the MNS _lat to DMS _lat difference (NMD: MNS _lat  - DMS _lat ) were also evaluated.
Results: Nerve conduction studies showed a sensory-motor polyneuropathy with axonal neurogenic pattern, as confirmed by needle EMG. Both MNS _amp and NMR were significantly reduced when compared to controls (p < 0.0001), whereas MNS _lat and NMD were markedly increased (p = 0.0049).
Conclusions: We have described COVID patients in the ICU with critical illness neuropathy (CIP). COVID-related CIP could have implications for the functional recovery and rehabilitation strategies.
(© 2021. Fondazione Società Italiana di Neurologia.)