Is there a post-SARS-CoV-2 vaccination dementia?

Letter to the editor

We read with interest the article by Vidyanti et al. about a 44 years-old male who developed slowly progressive cognitive deficits for 7 months, that worsened after vaccination against SARS-CoV-2 with the first dose of the Sinovac brand [1]. Additionally, 1 month after the vaccination, he developed progressive quadriparesis with distal predominance but without sensory disturbances [1]. The patient was diagnosed with “autoimmune dementia” and chronic inflammatory demyelinating polyneuropathy (CIDP) and partially recovered on prednisolone, mycophenolate mofetil, vitamin D, donepezil, and memantine [1]. The study is promising but raises concerns that should be discussed.

The diagnosis SARS-CoV-2 associated “autoimmune dementia” is incomprehensible for several reasons [1]. First, cognitive decline began as early as 6 months before vaccination. Second, no autoimmune disease had ever been diagnosed prior to the SARS-CoV-2 vaccination and post-vaccination work-up of autoimmune disease was inconclusive. Furthermore, there was no clinical or laboratory indication for cerebral vasculitis. Third, the patient had an ischemic stroke before and after vaccination, making vascular dementia more plausible than autoimmune dementia. We should know what classical cardiovascular risk factors were present.

We disagree with the diagnosis CIDP [1]. The patient does not meet the diagnostic criteria for CIDP, including progression over at least 2 months, motor > sensory symptoms, symmetric, proximal > distal involvement, reduced deep tendon reflexes throughout, dissociation cyto-albuminique, demyelination on nerve conduction studies (NCSs), and segmental demyelination on nerve biopsy [2]. Quadriparesis lasted only 1 month, there were no sensory deficits, there was distal predominance, no dissociation cyto-albuminque was detected, and no differentiation into a demyelinating or axonal lesion was performed on NCSs. More likely than CIDP, the patient had SARS-CoV-2 vaccination associated Guillain-Barre syndrome (GBS) because the patient developed quadriparesis within four weeks of vaccination, GBS is a common complication of SARS-CoV-2 vaccines, and has been reported in >2000 patients on the platform VigiBase [3] and ubiquitously [4].

Other limitations of the study are that no cerebral MRI with contrast medium, electroencephalography (EEG), or carotid ultrasound had been performed at the onset of the cognitive deficits and that the cause of multifocal and multiple ischemic stroke had not been identified. Since strokes occurred before and after vaccination, any classic cause of ischemic stroke must be ruled out in order to apply the most appropriate treatment. Since the distribution of multifocal strokes suggests embolism, we should know if the patient had atrial fibrillation, heart failure, arterial hypertension, diabetes, hyperlipidemia, or stenosis/occlusion of the cardiac arteries.

We should be informed of the results of the cerebrospinal fluid (CSF) tests, whether specific antibodies related to autoimmune encephalitis or vasculitis were elevated, whether the patient received intravenous immunoglobulins (IVIG), and what the outcome of quadruparesis was.

According to the X-ray in Fig. 1, the patient had a pericardial effusion, but according to the case description, the patient underwent thoracocentesis to treat “pleural effusions” [1]. Thus discrepancy should be resolved. According to Fig. 1, there was no pleural effusion at least on the right side.

Overall, the interesting study has limitations that call the results and their interpretation into question. The cognitive decline in the index patient was most likely due to recurrent ischemic stroke, and the quadriparesis was most likely due to SARS-CoV-2 vaccination related GBS.

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This article is based on previously conducted studies and does not contain any new studies with human participants or animals performed by any of the authors.

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The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.