Thread by @ZdenekVrozina

New study identifies 3 cognitive phenotypes in Long COVID - and raises a troubling question about insight and impairment.
123 adults
21 months post-COVID
All with some persistent cognitive complaints🧵

https://twitter.com/bagaidr/status/1944026157160013879

Participants:
Lab-confirmed SARS-CoV-2 infection
At least 3 months post-infection (median: 21 months)
Clinically significant cognitive complaints (eg attention, memory, planning)
No prior neurological or psychiatric diagnoses
Inclusion based on validated questionnaires: BRIEF-A & MMQ

Comprehensive assessment included:
Neuropsychological testing (memory, attention, executive function, processing speed)
Questionnaires (fatigue, sleep, psychological distress, quality of life)

72% had objective cognitive impairment, mostly in attention and executive function

Using latent profile analysis, researchers identified 3 cognitive profiles:

Profile 1 (28%)
Broad, measurable cognitive deficits
Strong subjective complaints
High fatigue and functional impairment

Profile 2 (52%)
Milder but detectable deficits
Moderate subjective complaints
Weak correlation between symptoms and test results

And

Profile 3 (20%)
Primary deficit in verbal long-term memory
Few or no complaints in that specific domain
“They had impaired performance in the long-term verbal memory domain but reported few complaints.”
“This mismatch … might suggest anosognosia.”

Let’s be precise:
The main objective deficit in Profile 3 was in verbal long-term memory.
These participants still met inclusion criteria based on overall subjective complaints - but not in the domain where impairment was objectively detected.

This is not a case of global dysfunction - but a specific, unrecognized cognitive impairment.
Still, even such isolated deficits can affect everyday life:
- learning, communication, verbal recall, work efficiency.

Core finding: subjective complaints and objective impairment often don’t align.
Some felt impaired - and were
Some felt impaired - but weren’t
Some were impaired - but didn’t know it
This last group is especially concerning.

Authors conclude:
Long COVID-related cognitive dysfunction is heterogeneous
Self-report is insufficient
Brief screens (eg MoCA) may miss real impairment
Rehabilitation should be tailored to profile

Interpret cautiously - but take it seriously?
Even 21 months post-infection,
1 in 5 participants had measurable memory impairment - without realizing it. Something is missing - and they don’t know it.