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Advanced Neurology Inflammatory myopathies during COVID-19

Table 5. The needle EMG parameters of the patients
Patient 1 (Dermatomyositis)
Findings Deltoid FDI VM TA
Spontaneous activity Fibrillations/positive sharp waves Not detected Fibrillations Fibrillations
MUAP duration Short Normal Short Normal
MUAP amplitude Small Normal Small Normal
Recruitment Early Normal Early Normal
Number of phases Polyphasic Occasional Polyphasic Occasional polyphasic Normal
Patient 2 (Polymyositis)
Findings Deltoid FDI VM TA
Spontaneous activity Not detected Not detected Fibrillations/positive sharp waves Not detected
MUAP duration Short Normal Short Normal
MUAP amplitude Small Normal Small Normal
Recruitment Early Normal Early Normal
Number of phases Polyphasic Normal Polyphasic Normal
Patient 3 (Polymyositis)
Findings Deltoid FDI VM TA
Spontaneous activity Fibrillations Not detected Not detected Not detected
MUAP duration Short Normal Short Normal
MUAP amplitude Normal Normal Small Normal
Recruitment Early Normal Early Normal
Number of phases Occasional Polyphasic Occasional Polyphasic Polyphasic Normal
Abbreviations: MUAP: Motor unit action potential; DL: Deltoid; FDI: First dorsal interosseous; VM: Vastus medialis; TA: Tibialis anterior.

predisposition and environmental factors that generate died after a severe COVID-19 infection thereafter, which
an immunological disruption that is poorly recognized . triggered a relapse and led to respiratory failure and death.
[16]
Whether complement fixation or antibody-dependent It is worth mentioning that the occurrence of myositis in
activation of the interferon pathway initiates that the the current sample is 44 times higher than the prevalence of
inflammatory cascade is still a matter of debate . myositis worldwide, which is equal to 0.005% (P < 0.001,
[18]
[17]
95% confidence interval = 0.1979 – 0.2421).
In the initial phase of this study, our main concern
was to detect the GBS cases related to COVID-19, Ten further instances of PM and DM after COVID-
estimate its prevalence, and describe its clinical and 19 infection had been recorded; at the time, this article
electrophysiological characteristics. During the GBS case was written. The United States reported four of these
collection period, however, we discovered three cases of instances, whereas Europe and Asia recorded four and two,
inflammatory myopathies among the COVID-19 patients: respectively [17,19] . Table 6 outlines the clinical characteristics
two out of three cases, one was a middle-aged man who of these ten instances.
was diagnosed clinically and electrophysiologically with The correlation between viral infections and their
PM after a severe COVID-19 infection, and the other was ability to trigger autoimmune disease is well-established in
a young lady with DM who was also suspected clinically the medical literature; nevertheless, the precise mechanism
and confirmed electrophysiologically after a moderate behind this association is likely complicated and unknown.
COVID-19 infection. A thorough survey was done for Several investigations have shown the existence of
those two cases to find any association with trigger factors, autoantibodies in COVID-19 patients. Furthermore, the
autoimmune disease, or paraneoplastic syndrome but COVID-19 genome includes 28 human proteins with similar
failed to yield any conclusion; hence, the post-COVID-19 sections to COVID-19 peptides, which may accelerate the
inflammatory myositis was suggested. On the other formation of autoantibodies . Inflammation produced by
[20]
hand, the present study reports only one case of PM in COVID-19 is an additional potential autoimmunogenic
the COVID-19 population, which was already diagnosed mechanism. COVID-19 is particularly dangerous, not due
before the onset of COVID-19 infection, and the patient to the virus itself but due to the inflammatory response

Volume 2 Issue 2 (2023) 5 https://doi.org/10.36922/an.378