81% of long COVID patients with dizziness on standing may have central sensitization

Key Findings

🔬 Virus Proteins in the Blood Fade Over Time — and Don't Track with Symptoms

A 2-year blinded study tracked SARS-CoV-2 protein fragments (antigens) in the blood of 425 people: 167 with long COVID, 148 fully recovered, and 110 never infected.

• At 6–12 months post-infection, 31% of long COVID patients had detectable viral antigens — but so did 20% of fully recovered people and 5.4% of never-infected controls.
• By 18–24 months, positivity dropped to just 3% in long COVID patients, and 0% in both other groups.
• Antigen levels were not linked to symptom type, symptom count, antibody levels, or vaccination status.

The full spike protein was the most commonly detected fragment; nucleocapsid was absent in recovered participants.

💉 Blood-Filtering Treatment for Long COVID Didn't Outperform Sham

A randomized crossover trial tested immunoadsorption — a process that filters autoantibodies (immune proteins that may mistakenly attack the body) from the blood — in 40 long COVID patients.

• No significant difference in symptom severity was found between the real treatment and the sham procedure on any measure: functional scale (OR 1.17), fatigue, cognitive function, handgrip strength, or overall symptom score.
• The treatment did successfully deplete autoantibodies against two receptor types (adrenergic and muscarinic G protein-coupled receptors) — the sham did not.
• 24 adverse events occurred with immunoadsorption vs. 10 with sham, suggesting a meaningful safety gap.

Autoantibody depletion happened as intended — it just didn't translate into symptom relief.

🫀 Long COVID Linked to Subtle Heart Function Changes — Especially in Older Adults

A meta-analysis of 17 studies covering 4,852 participants (3,173 with long COVID, 1,679 controls) found modest but measurable differences in heart function.

• 58% of long COVID patients had global longitudinal strain (GLS) below 16% — a threshold indicating subclinical left ventricular dysfunction (the heart's main pumping chamber squeezing slightly less efficiently than normal).
• Left ventricular ejection fraction (the percentage of blood pumped out per beat) was reduced by a mean of 1.30% in long COVID patients vs. controls.
• Cardiac dysfunction was more pronounced in older individuals and those with diabetes or high blood pressure.

These are small average differences, and their long-term clinical significance is still unclear.

🧪 Brain Activity Reduced in Key Cognitive Regions in Long COVID

Using ultra-high-field 7 Tesla fMRI (a particularly sensitive brain scanner), researchers compared 19 long COVID patients against 27 healthy controls (12 COVID-recovered, 15 never infected) during a cognitive task.

• Long COVID patients showed significantly lower brain activation in the anterior cingulate cortex and the precuneus — regions involved in attention, executive function, and self-awareness — compared to COVID-recovered controls.
• Lower activation in the precuneus was negatively associated with self-reported pain scores and duration of illness in long COVID patients.
• Long COVID patients had slower response times on both congruent and incongruent cognitive task conditions compared to never-infected healthy controls.

No significant differences were found between long COVID patients and never-infected controls in whole-brain comparisons.

💼 Mental Health Predicts Return to Work Better Than Most Long COVID Symptoms

A study of 128 employed long COVID patients tracked who returned to work and under what conditions.

• 65% returned to their usual duties (mean recovery time: 21 days); 20% returned under modified conditions (reduced hours or remote work) after a mean of 43 days; 10% couldn't return at all due to persistent symptoms.
• The top predictors of work status were global mental health, global physical health, emotional distress, recovery duration, and back pain — not most individual long COVID symptoms.
• Emotional distress and back pain were the exceptions among specific symptoms, showing meaningful associations with work outcomes.

📊 Social Disadvantage Strongly Linked to Higher Long COVID Risk

Using 2022 national survey data from 92,109 Americans who tested positive for COVID-19, researchers found that 22.14% reported long COVID — and social conditions were strongly associated with risk.

• Each step up on a 10-point social disadvantage scale (covering factors like income, housing, and access to care) was linked to progressively higher odds of long COVID: adjusted odds ratios of 1.47, 1.56, 2.26, and 3.21 for scores of 1, 2, 3, and ≥4 respectively (vs. score of 0).
• Non-Hispanic Black (aOR 0.82) and Asian (aOR 0.58) individuals were less likely to report long COVID than non-Hispanic White individuals — though Black and Hispanic respondents had higher odds of reporting joint/muscle pain specifically (aOR 3.03 and 3.11, respectively).
• Higher social disadvantage scores were linked to more joint/muscle pain, dizziness, and post-exertional symptoms, but lower rates of taste/smell loss.