We read with interest the article by Rastogi et al. about a 59yo female who experienced gait disturbance, incoordination, dizziness, diplopia, perioral paresthesias, right hand numbness, and lethargy 12 days after the second dose of a SARS-CoV-2 vaccine (Moderna) [1]. She had received the first dose (Astra Zeneca) three months earlier with no side effects [1]. Cerebral MRI showed numerous enhancing lesions in the cortex, deep grey matter, brainstem, and cerebellum [1]. No treatment was applied and the lesions resolved spontaneously almost completely within 10 days [1]. The study is valuable but raises concerns that warrant discussion.

We disagree with the term “binocular diplopia” [1]. There is no such thing as mono-ocular diplopia, so this term should be replaced.

There is a discrepancy between the patient’s initial description of symptoms including “lethargy” and the description on clinical examination that there was no change in personality or behaviour [1]. Lethargy is a change in behaviour.

The blood sedimentation rate and the determination of anti-nuclear antibodies (ANA) and anti-neutrophil cytoplasmic antibodies (ANCA) are missing. Cerebral vasculitis should have been ruled out, as it has previously been described as a complication of SARS-CoV-2 vaccinations [2]. There is no magnetic resonance angiography (MRA) or black blood sequences to document abnormalities of the cerebral arteries. 

There is no electroencephalography (EEG). The patient was described as having lethargy. An EEG should have been performed to rule out a non-convulsive status epilepticus.

How was acute, disseminated encephalomyelitis (ADEM) ruled out? ADEM has been reported as a side effect of SARS-CoV-2 vaccination [3] and is associated with spinal cord lesions but spinal MRI has not been performed. 

Has the gait disturbance been attributed to involvement of the cerebellum or is a spinal cord lesion conceivable? 

There is no determination of the CSF for cytokines and chemokines which have been shown to be upregulated in patients with CNS lesions after SARS-CoV-2 infection [4]. 

There is no determination of the CSF for the entire panel of autoantibodies associated with immune encephalitis and the determination of anti-ganglioside antibodies.

There is no explanation of the increased CSF glucose which should tell us if the patient was a diabetic or not.

SARS-CoV-2 vaccinations can be complicated by hypercoagulability and a propensity for thrombosis [5]. We should be told if the D-dimer and other blood coagulation parameters were normal and how venous sinus thrombosis (VST) had been excluded.

Disruption of the blood brain barrier could be an explanation for the described lesion, but is not supported by published data.

It is not clear why the patient received no treatment. Particularly, it remains unclear why no steroids were given. Most side effects of SARS-CoV-2 vaccinations are immune-mediated, which is why it is crucial to at least try steroids or intravenous immunoglobulins (IVIG) and see if they have a positive effect.

Overall, the interesting study has limitations and inconsistencies that call the results and their interpretation into question. Clarifying these weaknesses would strengthen the conclusions and could add value to the study. Emerging enhancing cerebral lesions after a SARS-CoV-2 vaccination require a comprehensive work-up to elucidate the underlying pathophysiology.