Cognitive, EEG, and MRI features in COVID-19 survivors

For the first time, long-term neurocognitive and neurophysiological consequences of COVID-19 have been assessed. Patients showed interrelated cognitive, EEG, and MRI alterations 2 months after hospital discharge. Cognitive and EEG findings improved at 10 months. Dysgeusia and hyposmia during acute COVID-19 were related to increased vulnerability of memory over time.

Cognitive impairment has been reported in 81% and 21% of patients at 3 and 6 months after SARS-CoV-2 infection, respectively [1,2]. Psychiatric disturbance is present in 56% after 1 month and in 25% after 6 months [3,4]. Proposed pathogenic contributors are direct cerebral viral invasion and cellular damage, systemic inflammation through cytokine release, and cerebral microvascular changes [5]. Neuropathological studies have shown pronounced microglia activation and microthrombosis within white matter, mainly in the brain stem. Concerns about long-lasting neurological consequences of COVID-19 are growing, but there is a lack of longitudinal studies with long-term follow-up and structured neuropsychological assessments, and there is a complete lack of EEG studies focused on the post-COVID-19 phase.

Dr Giordano Cecchetti (Vita-Salute San Raffaele University, Italy) and colleagues set up a study to explore cognitive, EEG, and MRI features in COVID-19 survivors up to 10 months after hospital discharge [6,7]. Patients (n=49) with a recent diagnosis of COVID-19 underwent neuropsychological assessments investigating the main cognitive domains (global cognition, executive functions, memory, visuospatial functions, language) and 19-channel EEG within 2 months after hospital discharge; 33 patients repeated this within 10 months. A brain MRI was additionally performed at baseline in 36 participants. Of the 49 participants, 42 (86%) were treated as inpatients and 13 (27%) required non-invasive mechanical ventilation (NIMV).

Two months after SARS-CoV-2 infection, 53% of patients had cognitive impairment (16% executive impairment, 6% memory impairment, 6% visual-spatial impairment, 25% multi-domain impairment) and 28% showed psychopathological disturbance (10% depression, 12% PTSD, 6% depression + PTSD). Executive dysfunction correlated with the severity of the acute-phase respiratory distress, which was measured using the National Early Warning Score (NEWS). After 10 months, the percentage of patients with cognitive impairment had decreased to 36% (3% executive impairment, 6% memory impairment, 6% visual-spatial impairment, 21% multi-domain impairment), whereas the percentage with psychiatric symptoms remained the same (6% depression, 18% PTSD, 9% depression + PTSD). Patients with dysgeusia/hyposmia during acute-phase COVID-19 showed a significantly slower recovery of cognition than those without. A lower EEG delta band at baseline predicted worse cognitive functioning at follow-up. MRI analysis revealed prominent cerebrovascular alterations in COVID-19 patients, correlating with worse memory function at baseline and with the total number of cardiovascular risk factors. On the other hand, no relation with severity of acute COVID-19 was found. Whether the observed alterations were directly linked to the infection or rather to its consequences is yet to be determined, as well as their reversibility.

1. Mazza MG, et al. Brain Behav Immun. 2021;94:138‒147.
2. Del Brutto OH, et al. Eur J Neurol. 2021;28(10):3245‒3253.
3. Mazza MG, et al. Brain Behav Immun. 2020;89:594‒600.
4. Huang C, et al. Lancet. 2021;397(10270):220‒232.
5. Heneka MT, et al. Alzheimers Res Ther. 2020;12(1):69.
6. Cecchetti G, et al. Cognitive, EEG and MRI features of COVID-19 survivors: a 10-month study. Contemporary Clinical Issues, AAN 2022, 02–07 April, Seattle, USA.
7. Cecchetti G, et al. J Neurol. Mar 6, 2022. DOI: 10.1007/s00415-022-11047-5.

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Posted on 2 June 202213 June 2022