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Advanced Neurology SARS-CoV-2 mechanisms of neurological impact

Table 6. Neuroimaging evidence of structural and functional brain changes in COVID‑19 survivors
Category Neuroimaging findings Affected brain Functional/clinical Current evidence and References
regions implications limitations
Acute phase • MRI finding: Signal • General • Early markers of • Predominantly observed 215-218
abnormalities detected in brain regions COVID-19-related in severe cases.
approximately one-third of with higher neurological involvement. • Limited longitudinal data
patients. prevalence in • Indicators of disease severity tracking progression from
• CT finding: Acute lesions, critical cases. and potential for acute brain acute to recovery phases.
particularly in severe cases injury. • Variability in imaging
requiring ICU admission. protocols across studies.
Recovery phase • Structural change: Reduced • Frontal regions • Lasting impact on brain • Based on cross‑sectional 213,219-221
cortical thickness. • Limbic regions structure and function. studies with varying
• Cerebral blood flow: • Potential for persistent follow-up durations.
Diminished perfusion. cognitive and emotional • Need for standardized
• White matter integrity: impairments. longitudinal studies
Alterations observed in to assess long-term
diffusion tensor imaging. trajectory.
Long-term • Gray matter: Persistent • Left temporal • Ongoing functional • Long‑term follow‑up 224-228
consequences reductions, especially in the lobe disruptions contributing studies indicate enduring
left temporal lobe, observed up • Precentral gyrus to cognitive deficits, changes in brain structure
to 2 years post-infection. • Angular gyrus neurological issues, and and function.
• Functional activity: Altered • Thalamus psychiatric symptoms. • Limited by small sample
resting-state fMRI activity in • Manifestation of long sizes and heterogeneity in
the precentral gyrus, angular COVID symptoms such as study populations.
gyrus, and thalamus. brain fog. • Potential confounding
factors not fully controlled.
Structural and • Amplitude of low‑frequency • Left putamen • Putamen and pallidum: • Findings suggest specific 223,224,237,238
functional fluctuations: Increased in • Right pallidum Alters motor and cognitive regional vulnerabilities.
changes the left putamen and right • Right insula functions. • Causality between
pallidum. • STG • Insula: Impacts emotional COVID-19 and observed
• Connectivity patterns: Altered • ITG regulation and cognitive changes remains unclear.
in the right insula and right • SPG processing. • Necessitates further
putamen linked to cognitive • Temporal lobe: Affects investigation into
failure. memory, language underlying mechanisms.
• Cortical thickness: Decreased comprehension, and sensory • Potential for overlapping
in the left putamen. processing. symptoms with other
• Temporal lobe damage: • Parietal gyrus: Impairs neurological conditions.
Involving the STG and ITG. visuospatial processing,
• Spontaneous activity: attention, and working
Decreased in the right SPG. memory.
• Potential compensatory
mechanisms in response to
brain damage.
Comparative • Differences in neuroimaging • Superior parietal • Highlights unique • Comparative studies are 224,230-232
analyses data: Significant disparities gyrus neurobiological impact of essential for isolating
between COVID-19 survivors • Pericalcarine COVID-19 compared to COVID-19-specific effects.
and healthy controls over cortex other viral infections. • Need to account for
2 years post-infection. • Parahippocampal • Enhances understanding confounding variables
• Mendelian randomization gyrus of specific cognitive such as pre-existing
studies: Association between impairments like brain fog. conditions and other
severe COVID-19 and reduced infections.
cortical surface area in regions • Further research is
such as the superior parietal required to generalize
gyrus, pericalcarine cortex, and findings across diverse
parahippocampal gyrus. populations.
Abbreviations: COVID: Coronavirus disease; CT: Computed tomography; fMRI: Functional magnetic resonance imaging; ICU: Intensive care unit;
ITG: Inferior temporal gyrus; MRI: Magnetic resonance imaging; SPG: Superior parietal gyrus; STG: Superior temporal gyrus.
(ALFF) in the left putamen and right pallidum compared to A 1-year follow-up fMRI study also found elevated ALFF
223
healthy controls, indicating altered brain activity (Table 6). values in the left putamen. These observations align with
Volume 4 Issue 2 (2025) 26 doi: 10.36922/an.4909