Brain MRI findings in patients with post COVID-19 condition: frequency and longitudinal changes in a nationwide cohort study, 2025, Furevik et al.

[SNT Gatchaman]

Brain MRI findings in patients with post COVID-19 condition: frequency and longitudinal changes in a nationwide cohort study

Spoiler: Authors

Furevik, Liv Lygre; Lapina, Oksana; Lindland, Elisabeth Stokke; Høgestøl, Einar August; Geier, Oliver Marcel; Devik, Kristina; Farmen, Anette Huuse; Flemmen, Heidi Øyen; Harbo, Hanne Flinstad; Morsund, Åse Hagen; Novotny, Vojtech; Ofte, Hilde Karen; Pedersen, Kenneth Ottesen; Popperud, Trine Haug; Ratajczak-Tretel, Barbara; Samsonsen, Christian; Selnes, Per; Torkildsen, Øivind; Undseth, Ragnhild Marie; Aamodt, Anne Hege; Beyer, Mona Kristiansen; Boldingh, Marion Ingeborg

BACKGROUND
Prolonged neurological symptoms following COVID-19 are common, yet few longitudinal studies describe brain MRI findings in this patient group. The use of contrast enhanced sequences is particularly lacking. We address this knowledge gap by reporting the frequency and longitudinal changes in brain MRI findings among patients with post COVID-19 condition exhibiting neurological symptoms.

METHODS
This prospective multicenter study included 140 adult patients referred for persistent neurological symptoms following COVID-19. Brain MRI was performed at both 6 and 12 months after infection onset, reporting white matter hyperintensities, cerebral microbleeds, and additional pathological findings including contrast enhancement. White matter hyperintensities were compared with a healthy control group.

RESULTS
The prevalence of white matter hyperintensities was comparable to healthy controls, and microbleeds were found at rates comparable to population studies, with longitudinal changes being infrequent. Lesions consistent with inflammation or demyelination were present in 4% (5/120) of patients at 6 months. Cranial nerve enhancement was found in 7% (7/94) of patients, persisting up to 12 months, predominantly affecting the oculomotor nerve. However, enhancement occurred without clinically detected ocular muscle paresis.

CONCLUSION
Our findings indicate that brain MRI primarily serves to exclude differential diagnoses in post COVID-19 condition, with limited clinical benefit of repeated imaging in the absence of new symptoms. However, signs of long-term inflammatory processes can be observed, and detection is improved by contrast enhanced sequences.

Web | DOI | PDF | Frontiers in Neurology | Open Access

 

[Utsikt]

if these findings are generalisable, would they demonstrate that most neurological and neuropsychiatric LC issues are probably not caused by major structural brain issues?

It’s also nice to see a paper that doesn’t mention any BPS factors. They essentially say that current imaging methods probably are not good enough to detect whatever is going on.

 

[SNT Gatchaman]

They essentially say that current imaging methods probably are not good enough to detect whatever is going on.

Yes the relevant pull quotes at the end of their discussion are —

Clinical research indicates that PCC often follows mild illness, and evidence suggests that the severity of the disease during the acute phase may not correlate with microstructural brain abnormalities. No clear distinction was observed between hospitalized and non-hospitalized individuals with [cranial nerve enhancement] in our cohort.

A clinico-radiological gap exists between prevalent neurological and cognitive complaints and brain findings identified through standard imaging techniques. Advanced, quantitative neuroimaging analyses—not yet established in clinical practice—show potential for detecting subtle neuronal changes, thereby deepening our understanding of underlying pathophysiological mechanisms.

i.e. #AllTestsAreNormal ain't.

 

[SNT Gatchaman]

if these findings are generalisable, would they demonstrate that most neurological and neuropsychiatric LC issues are probably not caused by major structural brain issues?

It depends what you mean by major structural. It's not large lesions like infarcts or widespread demyelination or inflammatory changes. But it may still be "major" but happening in a generalised fashion at a microstructural level, particularly affecting white matter or causing blood-brain barrier dysfunction. That may still be reversible, however, if say the underlying signalling was corrected.

I note these comments about white matter hyperintensities —

Our findings do not indicate that these hyperintensities continue to develop beyond 6 months following infection.

Within the PCC group, 5% (4/88) developed one new WMH lesion, while another 5% (4/88) showed a reduction of one lesion.

 

[Utsikt]

It depends what you mean by major structural.

Good point. I meant permanent structural damage to neurons or other important infrastructure.

It seems like it’s more likely that there are some shifts in dynamic systems that maintain an undesirable state.