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Reversible Vascular Causes of Dementia-Like Symptoms: Dural Arteriovenous Fistula & Chronic Subdural Hematoma

When a loved one suddenly develops confusion, memory trouble, or difficulty walking, it's natural to fear the worst. But some rare vascular conditions—like a dural arteriovenous fistula (dAVF) or a chronic subdural hematoma (cSDH)—can mimic dementia and are potentially reversible with prompt treatment. These conditions involve abnormal blood flow or bleeding that puts pressure on the brain, and catching them early can lead to significant improvement. This article will help you recognize the warning signs, know what to ask your doctor, and take concrete steps toward a proper diagnosis.

Key points

  • Sudden or rapid-onset cognitive symptoms (over days to weeks) may be due to a reversible vascular cause, not progressive dementia.
  • Chronic subdural hematoma and dural arteriovenous fistula are rare but treatable conditions that can mimic dementia.
  • Always request brain imaging (CT or MRI) if symptoms appear quickly, especially after a fall or head bump.
  • Keep a detailed symptom diary and medication list, including blood thinners.
  • Do not assume it's 'just aging'—advocate for a specialist referral to a neurologist or neurosurgeon.
  • After treatment, cognitive improvement can be significant, but recovery may take weeks.

What Are These Conditions and Why Do They Mimic Dementia?

A dural arteriovenous fistula is an abnormal connection between an artery and a vein in the protective covering of the brain (the dura). This causes blood to flow directly from a high-pressure artery into a low-pressure vein, bypassing the normal capillary network. Over time, this can lead to increased pressure in the veins, reduced blood flow to brain tissue, and even tiny bleeds. The result can be a gradual or sudden onset of cognitive symptoms—like trouble with planning, memory lapses, or confusion—that look very much like dementia. Chronic subdural hematoma is a collection of old blood that slowly builds up between the brain and its outer covering, often after a minor head injury that may have been forgotten. As the blood accumulates, it pushes on the brain, causing symptoms that can include headache, drowsiness, difficulty walking, and changes in thinking or personality. Both conditions are rare, but they are important to know about because they can be treated—often with surgery or endovascular procedures—and the cognitive symptoms can improve dramatically.

How Are They Different from Typical Vascular Dementia?

Typical vascular dementia is caused by long-term damage to small blood vessels from conditions like high blood pressure, diabetes, or multiple small strokes. It usually progresses in a stepwise fashion—sudden declines followed by plateaus—and is not reversible. In contrast, dAVF and cSDH are structural problems that can be fixed. The key difference is that symptoms from these reversible conditions often come on more rapidly (over weeks to a few months) and may be accompanied by other signs like a persistent headache, unsteady gait, or a history of a fall or head bump. If your loved one has a sudden change in cognition, especially if they have any risk factors like blood-thinning medications or a recent fall, it is critical to push for brain imaging (like a CT or MRI) to rule out these possibilities.

General caregiving information, not medical advice. Check medications and major care changes with your clinician.

Step-by-step

  1. Keep a symptom diary: Write down when symptoms started, how quickly they changed, and any new physical signs like headache, dizziness, or trouble walking. Note if your loved one had a recent fall or bump to the head, even if it seemed minor.

  2. Call the primary care doctor or neurologist immediately: Say, 'My family member has had a sudden change in thinking or memory over the past few days or weeks, and I'm worried it could be a treatable vascular problem like a subdural hematoma or a fistula. Can we get an urgent brain scan?'

  3. Request a brain CT scan without contrast as a first step: This is the quickest way to spot a chronic subdural hematoma. If the CT is normal but symptoms persist, ask for an MRI with contrast, which is better at detecting a dAVF.

  4. If a dAVF is suspected, ask for a referral to a neurosurgeon or interventional neuroradiologist: These specialists can perform a cerebral angiogram, which is the gold standard test to see the abnormal blood vessels.

  5. For chronic subdural hematoma, ask about surgical drainage: This is often done through a small hole in the skull (burr hole) and can relieve pressure on the brain quickly, sometimes leading to dramatic improvement in cognition within days.

  6. If surgery is recommended, discuss the risks and benefits with the surgeon, especially if your loved one is on blood thinners. The doctor may need to temporarily stop or reverse these medications before the procedure.

  7. After treatment, watch for improvement over the next few weeks: Keep a log of changes in memory, mood, and walking ability. Report any new symptoms like worsening headache or drowsiness to the doctor immediately.

What not to do

  • Do not assume it's just 'old age' or 'normal dementia' without a scan: Many caregivers dismiss sudden changes as part of aging, but a reversible condition could be missed. Always push for imaging if symptoms appear rapidly.

  • Do not wait for symptoms to go away on their own: Chronic subdural hematomas and dAVFs do not resolve without treatment. Waiting can lead to permanent brain damage.

  • Do not forget to mention any recent falls or head bumps: Even a minor bump weeks ago can cause a chronic subdural hematoma, especially in older adults or those on blood thinners. Write down the date and details.

  • Do not stop blood thinners without a doctor's guidance: If your loved one takes medications like warfarin, apixaban, or aspirin, never stop them on your own. The doctor will decide if and when it is safe to pause them.

  • Do not rely on a normal CT scan to rule out everything: A dAVF may not show up on a standard CT. If symptoms persist, insist on an MRI or a referral to a specialist.

Practical tools

  • Symptom Timeline Template

    Create a simple chart with dates and symptoms. Columns: Date, Symptom (e.g., confusion, headache, unsteady walking), Severity (1-10), Any fall or head bump. Bring this to every doctor visit.

  • Doctor Visit Script for Urgent Imaging

    Say: 'My [mother/father] has had a sudden change in memory and thinking over the past [days/weeks]. They also have [headache/trouble walking]. I'm concerned about a reversible vascular cause like a subdural hematoma or a fistula. Can we get a brain CT or MRI today?'

  • Medication List Card

    Write down all medications, especially blood thinners (e.g., warfarin, apixaban, rivaroxaban, clopidogrel, aspirin). Include doses and when last taken. Keep a copy in your wallet and give one to the ER doctor.

  • Fall History Log

    Note any falls or head bumps in the past 3 months, even if they seemed minor. Include the date, what happened, and if there was any loss of consciousness or dizziness afterward.

  • MRI Request Letter Template

    If the CT is normal but symptoms persist, ask the doctor to write a referral for an MRI brain with contrast. You can say: 'The CT was clear, but my loved one's symptoms are getting worse. Can we do an MRI to check for a dural fistula?'

  • Post-Treatment Recovery Checklist

    After surgery or treatment, track: daily cognition (e.g., can they remember a short list?), walking stability, headache severity, and mood. Report any new symptoms like seizures or worsening confusion to the doctor.

Discuss with your clinician

Ask: 'Could my loved one's symptoms be caused by a dural arteriovenous fistula or a chronic subdural hematoma? What imaging would you recommend to rule these out?'

Ask: 'If a chronic subdural hematoma is found, what are the risks and benefits of surgical drainage for someone of my loved one's age and health?'

Ask: 'If a dAVF is found, what treatment options are available? Is endovascular embolization an option?'

Ask: 'Should we temporarily stop any blood thinners before imaging or surgery? If so, how and when?'

Ask: 'What signs of worsening should I watch for after treatment, and when should I call you or go to the ER?'

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