Functional neurologic disorder associated with SARS-CoV-2 vaccination.

CMAJ | August 15, 2022 | Volume 194 | Issue 31 © 2022 CMA Impact Inc. or its licensors A healthy 50-year-old woman developed involuntary movements of her legs about 4 days after her first dose of vaccine against SARSCoV-2. These involuntary jerks progressed to involve the rest of her body. The movements occurred intermittently during the day, lasting for seconds, but they affected her gait so that she required a cane to walk. In addition, she described fatigue, headache and intermittent paresthesia and pain in different parts of her body. She reported being stressed because of the pandemic and was initially hesitant to receive the SARS-CoV-2 vaccine, but had decided to get her first dose because she was employed in the education sector. She had no history of smoking, recreational drug use or substantial alcohol intake. She had no relevant medical history and no psychiatric history. During childhood, she had had psychological trauma that would be considered an adverse childhood experience. She reported no family history of any neuro logic disorders. Her involuntary movements were pronounced during the physical examination, with “twitching” of her face during activation of her frontalis, and jerky movements of her arms during pronator drift. Her atypical movement patterns (with variability, distractibility and entrainment) were suggestive of a functional movement disorder. The patient had been assessed previously at an emergency department, with consultation to general neurology to investigate potential causes of her acute-onset atypical movements. All laboratory investigations were normal. A computed tomography (CT) venogram and magnetic resonance imaging (MRI) scans of her brain and cervical spine with contrast ruled out structural lesions, including venous sinus thrombosis. A normal electroencephalogram (EEG) showed no evidence of epileptiform activity. She was referred to our functional neurologic disorders clinic for further assessment. Given the clinical findings and normal investigations, the patient received a diagnosis of functional neurologic disorder (FND) following SARS-CoV-2 vaccination. We explained the diagnosis to her and offered FND-associated physiotherapy. In the following weeks, she noticed gradual improvement in her symptoms and no longer required a cane for ambulation. During the consultation she asked, “Is it safe for me to get the second shot?,” as she was worried about developing worsening or new symptoms. Despite our encouragement that she do so, she decided not to receive any further vaccine doses. Discussion