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The elusive nature of brain fog -

Despite its prevalence, brain fog remains a poorly defined medical phenomenon, often lacking a clear diagnostic criterion. Scientists have only recently started piecing together what causes it.

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Long COVID’s hazy aftermath -

A significant number of individuals who recover from COVID-19 experience lingering cognitive symptoms referred to as brain fog. These can include poor concentration, memory lapses, and difficulty with daily tasks, all of which severely impact their quality of life post-infection.

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Beyond COVID -

Although COVID-19 brought the term “brain fog” into public awareness, it has long been recognized in people suffering from chronic conditions such as fibromyalgia, lupus, chronic fatigue syndrome, and even as a side effect of medications or chemotherapy.

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Chronic illness and cognitive challenges -

Patients battling chronic conditions frequently describe brain fog as one of the most debilitating symptoms. Common complaints include an inability to focus, mental confusion, forgetfulness, and a general slowing down of thought processes that interfere with everyday living.

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Shared symptoms -

Regardless of the underlying condition, brain fog manifests similarly across different illnesses. Neuropsychologists have noted that this includes clouded thinking, poor memory, and sluggish cognition.

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A vague term -

The term “brain fog” lacks a strict clinical definition and isn’t considered a standalone diagnosis. Instead, it serves as a catch-all for cognitive issues stemming from various medical conditions, which can complicate both diagnosis and treatment.

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Functional deficits -

Experts believe brain fog reflects issues in critical cognitive functions. It indicates that the brain is not operating optimally, even if standard medical tests don’t show measurable abnormalities.

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Lack of clinical proof -

Patients often feel invalidated when test results fail to confirm their cognitive struggles. Many undergo extensive evaluations, only to be told their brain function appears normal. This leads to frustration and feelings of being misunderstood or dismissed by clinicians.

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Dismissal of symptoms -

There is a tendency among some healthcare providers to attribute brain fog purely to psychological causes. This bias particularly affects people with long COVID or chronic illnesses, and contributes to a delay in treatment.

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Multiple potential causes -

Researchers now believe that brain fog likely stems from a variety of causes, differing between individuals and conditions. This growing consensus may open doors to more nuanced and targeted approaches to understanding and addressing this complex symptom.

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A central theory -

One prevailing hypothesis is that brain fog results from neuroinflammation. Conditions like long COVID can trigger an overactive immune response, which persists even after the initial illness subsides, and disrupts brain function through ongoing inflammation.

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COVID’s lingering effects -

Research suggests that COVID-19 may activate immune cells in the brain and disrupt neuronal growth. This leads to cognitive decline and structural brain changes, including reduced gray and white matter, all of which contribute to long-term brain fog.

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Autoantibodies -

In some cases, COVID-19 prompts the production of autoantibodies, which mistakenly attack healthy brain cells. This autoimmune response may further aggravate neuroinflammation and cause persistent cognitive deficits in individuals recovering from the virus.

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Viral reservoirs -

Scientists believe remnants of the virus may even linger in the brain, keeping the immune system in a state of high alert. This continuous immune activity can result in prolonged inflammation and cognitive issues among long COVID sufferers.

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Leaky blood-brain barrier -

A recent study found that many long COVID patients with brain fog had leaky blood-brain barriers. This barrier normally protects the brain from harmful substances, but when compromised, it can let in toxins and worsen cognitive dysfunction.

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The danger of barrier breaches -

When the blood-brain barrier becomes permeable, it allows harmful elements to enter the brain, which can ignite inflammation and interfere with metabolism. This further contributes to the onset and persistence of brain fog symptoms.

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The hormonal connection -

Changes in hormone levels, such as during menopause, have been associated with reductions in brain region sizes and cognitive performance. These hormonal shifts might be a significant but underexplored factor contributing to brain fog symptoms.

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Thyroid dysfunction -

In people with hypothyroidism, insufficient thyroid hormones are linked to reduced brain volume. This is especially true in the hippocampus, which may impair memory and thinking.

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Traumatic brain injuries -

Brain fog symptoms are also common after traumatic brain injuries. These cases often involve low levels of growth hormone, which can affect brain function and mimic the same cognitive difficulties seen in long COVID and other conditions.

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Gut-brain axis -

Interestingly, the gut microbiome might also influence brain fog. Some studies have linked digestive conditions to cognitive haziness, potentially through microbial imbalances that promote systemic inflammation and affect brain health.

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Microbial imbalance -

Researchers believe the gut-brain connection might play a role in long COVID-related brain fog as well. Disruptions in gut bacteria could contribute to inflammation and brain changes, although this hypothesis still requires further investigation.

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Lifestyle choices -

Experts recommend addressing lifestyle factors like exercise, diet, and sleep first. These foundational habits can improve overall brain health and may reduce mild cases of brain fog.

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Seeking medical assessment -

Persistent or severe brain fog should prompt a visit to a doctor. Clinicians can rule out reversible causes (such as sleep apnea or nutritional deficiencies) and look for signs of inflammation or neurodegenerative diseases.

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Brain training -

Cognitive rehabilitation therapy can help patients with significant cognitive impairments. This type of therapy targets the brain’s weakest areas, functioning like mental exercise to rebuild cognitive strength and enhance overall mental performance.

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Repurposing drugs -

Some patients (especially those with chemo-related brain fog) report improvements with ADHD medications. These treatments may help improve focus and attention, though more research is needed to determine their broader effectiveness.

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Anti-inflammatory treatments -

Antihistamines and drugs like famotidine (which possess anti-inflammatory properties) are being investigated for their potential to relieve brain fog. Early results are promising, particularly for reducing inflammation associated with long COVID.

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Immunotherapy -

Medical practitioners are also looking into intravenous immunoglobulin (IVIG) as a means of treatment. It involves the infusion of donated antibodies, which is typically done for autoimmune diseases. The goal is to suppress harmful immune activity and protect brain cells from damage.

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Harnessing cancer therapies -

Researchers are also looking into checkpoint inhibitors (used in cancer immunotherapy) as a treatment for long COVID. These drugs may help recalibrate the immune response and reduce the neuroinflammation believed to cause brain fog.

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Continuing the quest for clarity -

Despite its vague terminology, brain fog is a real and deeply disruptive symptom for many people. Instead of dismissing it, researchers and doctors are now viewing it as a valuable window into broader neurological dysfunctions that they could potentially treat in the future.

Sources: (National Geographic) (News-Medical)

See also: Understanding the concept of brain rot

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