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Advanced Neurology Inflammatory myopathies during COVID-19

3.4. The clinical and neurological characteristics of including the deltoid and vastus medialis muscles, with
the patients polyphasia and early recruitment of MUAPs.
One of the cases had been diagnosed as DM with a 4. Discussion
negative initial paraneoplastic screen and positive
anti-Jo-1 antibodies, anti-mitochondrial M2 antibodies, In the post-COVID-19 period, the occurrence of PM is
[10]
and anti-exosome antibodies (PM/SCL 100). In contrast, unusual, with very few instances reported . In patients
the two others have been diagnosed with PM, one of who develop nonspecific symptoms after recovering
them had a negative autoimmune workup, and the other from COVID-19, it is essential to consider all possible
had only positive anti-nuclear antibodies (ANA) with causes, including PM. According to research, PM is
no other available antibodies workup. The details of the an autoimmune disorder induced by a virus and/or an
neurological history and examination are clarified in inflammatory condition, although the precise etiology is
[11]
Table 4. unclear .
In addition, since the beginning of the COVID-19
3.5. The electrophysiological characteristics of the pandemic, the prevalence of DM has increased
patients dramatically [12-14] . For instance, the rate of new cases
The nerve conduction studies of the three patients were of juvenile DM admitted to a tertiary care hospital in
reported to be normal, apart from a mild axonal pattern Iran between February 2020 and February 2021 was
of damage affecting the motor nerves of the third patient. approximately four times that of the preceding decade .
[13]
Table 5 describes the EMG features of the three patients Moreover, it was reported that DM patients suffered
who were diagnosed with inflammatory myositis, which numerous relapses during the COVID-19 pandemic .
[15]
show myopathic MUAPs, especially in proximal muscles, The disease is caused by a combination of genetic

Table 4. The clinical and neurological characteristics of the patients
Neurological characteristics Patient 1 Patient 2 Patient 3
Diagnosis Dermatomyositis Polymyositis Polymyositis
Creatinine kinase 6588 U/L 5170 U/L 7322 U/L
Autoimmune screen Anti Jo-1 Negative ANA positive
AMA M2
PM/Scl 100
Paraneoplastic screen Negative Negative Negative
Time of onset of neurological 1 week 3 weeks 5 days
complaints in relation to COVID-19
Limb weakness Proximal upper Proximal upper Proximal and distal
and lower limbs and lower limbs upper and lower limbs
Sensory features None None None
Sphincter dysfunction None None None
Dysphagia/Dysarthria None None Present
Dyspnea Mild Severe Severe
Skin lesion Present None None
Facial asymmetry None None None
Muscle wasting None None Present
Muscle fasciculation None None None
Tone Normal Decrease Decrease
Power * Grade 4 Grade 4 Grade 0
Reflexes Present Present Decreased
Coordination Normal Normal Not assessed
Sensory exam Normal Normal Normal
Abbreviations: MRC: Medical research council; AMA: Anti-mitochondrial M2 antibodies; PM/Scl 100: Anti-exosome antibodies. *Power assessment
was depend on MRC grading which is a universal grading system for power.

Volume 2 Issue 2 (2023) 4 https://doi.org/10.36922/an.378