Fever, Myositis, and Paralysis: Is This Inflammatory Myopathy or Neuroinvasive Disease?

Abstract

West Nile virus (WNV) is a mosquito-borne RNA Flavivirus which emerged in North America in 1999. Most patients present with a febrile illness but a few develop WNV neuroinvasive disease. Myopathy is an uncommon manifestation. We describe a case of a 42-year-old male from Los Angeles who presented with 8 days of fever and muscle pain. Initial physical exam was normal except for 4/5 muscle strength testing in his extremity proximal muscles. Laboratory revealed a creatine kinase of 45,000 and a urinalysis with large blood but no red blood cells, suggesting rhabdomyolysis. The patient's condition declined despite aggressive supportive care and hydration, and on hospital day #6 he developed severe altered mental status and progressed to complete right arm paralysis and 2/5 muscle strength in bilateral legs. EMG/NCS showed sensorimotor axonal polyneuropathy and the cerebrospinal fluid was positive for IgM and IgG WNV antibodies. The patient was diagnosed with WNV neuroinvasive disease, poliomyelitis (and encephalitis) type with myopathy/muscle involvement. He was treated supportively and his muscle and neurologic disease gradually improved. At 12-month follow-up his muscle enzymes had normalized and his weakness had improved to 5/5 strength in bilateral legs and 3/5 strength in the right arm.

Differentiation-dependent susceptibility of human muscle cells to Zika virus infection

“…The main clinical features of acute ZIKV infection are fever, rash, arthralgia, peri-articular edema, and myalgia [5]. The latter has been also reported associated with other arboviral infections (dengue, chikungunya and West Nile viruses) [6], [7], [8]. During the recent outbreaks, a clear association has been demonstrated between ZIKV infection and neurological syndromes.…”

“…In addition, muscle involvement has been extensively described in other arbovirus infections: alphaviruses, such as Mayaro, chikungunya and Sindbis viruses, have been reported to cause myalgia and myositis in humans [24] [7], [25], [26], and flaviviruses, e.g. West Nile and dengue viruses, have been associated with myositis [6], [8] and rhabdomyolysis [27], [28]. Although the mechanisms of such myopathies may be indirect, related either to viral-induced dehydration/hypophosphatemia, or myocytotoxic cytokines, the probability of a direct muscle cell targeting by the virus may be hypothesized.…”

Arboviruses and Muscle Disorders: From Disease to Cell Biology

“…Of note, myositis may occur following infection from arthrogenic (e.g., RRV, CHIKV, SINV), encephalitic/neurotropic (e.g., WNV, ZIKV, tick-borne encephalitis virus (TBEV)), or hemorrhagic arboviruses (e.g., DENV). Neurogenic myositis was reported to be associated with WNV, CHIKV, and ZIKV, as a consequence of polio-like, transverse myelitis, and Guillain-Barré syndromes, respectively [33][34][35]. Myositis has been described in one case report during CHIKV infection [36], and in two CHIKV positive patients with detection of infected cells (satellite cells, i.e., muscle progenitor cells) in muscle, in one of them several months post-infection [37].…”