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Symptoms of Cavernous Malformation

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A cavernous malformation, also known as a cavernoma or cavernous angioma, is an abnormal cluster of blood vessels typically 1 to 5 cm (about 0.5 to 2 inches) in size. These blood vessels lack normal walls, leading to periodic leakage of blood. Seizures are a common symptom. If you or your loved one has been diagnosed with a cavernous malformation, read on to learn more about what the symptoms entail and why they occur.  

What Are the Symptoms of a Cavernous Malformation?

Common symptoms of a cavernous malformation include seizures and neurological problems (weakness, numbness, and other neurological issues) depending on its location. Neurological symptoms can differ for each patient depending on the function of the surrounding brain tissue being affected.

Many of the symptoms of a cavernous malformation can mimic other unrelated neurological conditions. If you experience concerning symptoms, consult a medical professional for a thorough investigation to determine the cause.

Symptoms of a cavernous malformation are detailed next.


Cavernous malformations can vary in size and become as large as a golf ball or strawberry in diameter. A large mass can place pressure on surrounding tissues such as blood vessels and nerves, causing pain and the perception of a headache.

Headaches that increase in frequency, are particularly severe, or are unlike headaches that you have had in the past should be checked out further. Although headache is one possible symptom of a cavernous malformation, a headache on its own is common and can be associated with many other conditions.


Blood leaking from a cavernous malformation can irritate surrounding tissues and cause abnormal electrical activity within the brain, also known as seizures. You may or may not lose consciousness during the seizure depending on the amount of brain that the seizure involves.

In contrast to the characteristic full-body shaking that comes to mind when seizures are mentioned, seizures involving less brain tissue may be subtle and involve slight abnormal movements from certain body parts or the sudden onset of odd perceptions such as a specific smell or taste.

Neurological Problems

The location of a cavernous malformation determines the type of symptoms a patient may experience. Different parts of the brain control various functions, all of which can be impaired by the presence of a malformation. For example, if a cavernous malformation forms near the area responsible for speech, then trouble speaking or slurring of speech may occur. Below are several other possible neurologic deficits, or problems, to watch out for.

Vision Difficulties

Visual information is transmitted to the brain via the optic nerves. Specifically, this information travels to the back of the brain in a region called the occipital lobe. If a large cavernous malformation forms anywhere near this pathway, visual problems such as blurriness, double vision, light sensitivity, or vision loss can occur.   

Balance Problems

The vestibular nerve within your inner ear is responsible for maintaining your balance and awareness of where your body is in space. A cavernous malformation located near this pathway in the brainstem can cause unsteadiness, dizziness, vertigo, falls to the side of the body where the malformation is located, or a constant floating sensation.

Weakness or Paralysis in Arms or Legs

Voluntary movement of the arms and legs occurs by signals traveling from the brain to the spinal cord, then to the muscles responsible for performing the intended actions. Cavernomas pressing against structures involved in this pathway can cause weakness or paralysis.

Other neurologic deficits can involve speech, language, sensation, thinking, memory, mood, or personality. Depending on its location, a cavernous malformation may cause memory loss and behavioral disturbances that can be particularly concerning. On the other hand, some patients may not experience any symptoms at all.

Risks of Cavernous Malformations

When it comes to cavernous malformations, the main concern is the risk of bleeding into the surrounding brain. Upon rupture, blood from a cavernous malformation can irritate neighboring brain tissue and cause seizures or other neurological problems, or even very rarely death. The annual risk of bleeding from a previously undiagnosed cavernous malformation is typically less than 1% but can increase to 3% to 5% for cavernous malformations that have previously bled or are in the brainstem.

Bleeding From Cavernous Malformations

A cavernous malformation is by nature leaky. With thin walls lacking normal strength and structure, a cavernous malformation can periodically ooze blood. Upon rupture, a more concerning bleed into the brain occurs (intracerebral hemorrhage). Bleeding from a cavernous malformation is typically slower than that of an arteriovenous malformation (AVM). However, this can still be a life-threatening event.

The cause or trigger of bleeding has not been determined. In general, bleeding from a cavernous malformation is rare (1%–5% per year), especially if it has never bled before. There is no evidence to support the role of stress in causing a cavernoma to bleed. However, a diagnosis of a cavernous malformation and the potential risk of hemorrhage can indeed be stressful.

Determining whether treatment is necessary will depend on the severity of symptoms and a thorough analysis of the risks and benefits associated with each treatment option. Do not hesitate to seek a second opinion if you would like further insight into your diagnosis. An experienced neurosurgeon can make a big difference in choosing and delivering the right treatment for you.

Key Takeaways

  • Symptoms of a cavernous malformation include seizures, headaches, and neurological problems.
  • The exact symptoms depend on the location and size of the cavernous malformation.
  • Although bleeding from a cavernous malformation is rare, it can be life-threatening.