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.