More Than Just a Cold: A Case of Critical Illness Polyneuropathy with Mononeuritis Multiplex Following COVID-19 Infection

ABSTRACT

Case Diagnosis Critical Illness Polyneuropathy following COVID-19 Infection Case Description or Program Description A 58-yearold female presented to PM&R clinic following a prolonged hospitalization for COVID-19, after which she developed bilateral wrist and foot drop. Prior to her hospitalization, she ambulated independently. At the time of evaluation, she was wheelchair bound. Physical exam demonstrated bilateral wrist and foot drop, with bilateral foot numbness. EMG demonstrated bilateral common peroneal incomplete axonal neuropathy, with bilateral incomplete axonal brachial plexopathy affecting mainly the lower trunk on the left side and the middle cord on the right side. Setting(s) Tertiary-care teaching hospital Assessment/Results: Outpatient physical and occupational therapy were initiated and she was prescribed bilateral ankle foot orthoses. She was referred to neurology, with diagnosis of multifocal axonal neuropathy, with critical illness polyneuropathy, post viral (COVID) immune axonopathy with mononeuritis multiplex. Repeat EMG obtained 8 months later demonstrated mild improvement on the needle study with decreased denervation potentials of the muscles tested however, NCS remained unchanged. Over a 1-year span of therapy, her strength, function and numbness improved. She progressed to ambulate independently without an assistive device. Discussion (relevance) Critical illness polyneuropathy (CIP) is a neurologic manifestation of systemic inflammatory response syndrome, causing axonal injury by unclear mechanism. It is suspected that distal nerve microcirculation causes ischemia and axonal degeneration. There are increasing reports of polyneuropathy following COVID-19 infection. Diagnosis involves EMG, which demonstrates axonal loss without demyelinating features, with NCS showing decreased amplitude of SNAPs. CIP treatment includes reduction of dose and duration of steroids and neuromuscular blocking agents, rehabilitation programs, and careful extremity positioning. Conclusion(s) Our patient experienced functional improvement with conservative management, including outpatient physical and occupational therapy with bracing. As the COVID-19 pandemic continues, CIP must be considered in patients with weakness and a history of COVID-19 infection, particularly in those with severe infection and ICU stay.