Dados do Trabalho

Título

Propriospinal myoclonus post-SARS-CoV-2 infection and exposition to COVID-19 vaccination: causal relationship or coincidence?

RESUMO

Case presentation: A previously healthy 34-year-old man presented with episodes of focal spasms affecting the right shoulder and causing right-sided flexion of the trunk along with abdominal muscle contractions evolving with progressive worsening for 20 days. He observed that the abnormal movements increase with stressful events and disappear when he was sleeping. Thirty days before, he presented flu symptoms associated with anosmia and ageusia that recovered in seven days. He did not search for medical assistance and received Aztrazeneca COVID-19 vaccination 15 days after improvement. Magnetic resonance images of the spinal cord, laboratory tests including autoantibodies, and neoplastic screening were unremarkable. SARS-CoV-2 IgG antibodies were positive. Electromyography showed motor unit potential bursts between 50-150ms without rhythmic pattern indicating myoclonus in the right-side trunk flexor musculature that changed with body positioning. During polymyography, the electroencephalogram showed no epileptic paroxysms before or after myoclonus, and the Bereitschafts evoked potential was not obtained. The patient received benzodiazepines associated with anticonvulsants and improved. Case discussion: The clinical features and the electrodiagnosis were indicative of propriospinal myoclonus, which is a rare condition characterized by repetitive, often arrhythmic spasms in the flexor muscles of the trunk, hips, and knees following a regular pattern. It is possible that a spinal cord generator causes this kind of abnormal movement. Diagnosis is challenging due to the possibility of a functional movement disorder, elevated frequency of normal images, and a broad range of triggers (such as viral infections and drugs). There are no biomarkers for this disorder. Among all post-COVID-19 movement disorders previously published, two-thirds are reported as myoclonus, including one case associated with mRNA vaccination. It is possible that they occur due to either neuronal hyperexcitability or post-viral autoimmune syndrome. There is one case report of propriospinal myoclonus post-SARS-CoV-2 infection, but not after any COVID-19 vaccination. Final comments: Propriospinal myoclonus is a rare movement disorder. Relationship with immune triggers such as SARS-Cov-2 infection or COVID-19 vaccines may contribute to the pathophysiological knowledge of the disorder, especially when there are no other usual causes.

Palavras Chave

Propriospinal Myoclonus, SARS-CoV-2 Infection, COVID-19 Vaccination