Reversible cerebral vasoconstrictive syndrome is a condition that causes sudden, severe “thunderclap” headaches and other disruptive brain symptoms. The symptoms often resemble those of medical emergencies like strokes or brain bleeds. Emergency care is absolutely critical if you experience any of these symptoms (or are with someone having them).
Reversible cerebral vasoconstriction syndrome (RCVS) is a condition that happens when blood vessels suddenly spasm and constrict (tighten or narrow) in your brain. Sudden and extremely painful thunderclap headaches are a telltale sign of RCVS. It can also cause symptoms that are very similar to a migraine or a stroke, or bleeding into your brain.
Thunderclap headaches are a medical emergency. They’re the main symptom of bleeding in and around your brain. If you have (or are with someone who has) a headache that starts suddenly, reaches maximum intensity right away or “feels like the worst headache I’ve ever had,” call 911 (or your local emergency services number) immediately.
RCVS is sometimes known as Call-Fleming syndrome. That name comes from two physicians, George Call and Marie Fleming, who first recognized RCVS as a distinct condition and described it in 1988. But that name isn’t widely used.
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The symptoms of RCVS all come from disruptions in blood circulation throughout your brain. This causes:
RCVS can also cause subarachnoid hemorrhage (SAH), a type of bleeding between your brain and skull (also known as a brain bleed). SAH is a medical emergency. In addition to the RCVS symptoms above, SAH symptoms can include:
Your blood vessels have a lining of smooth muscle inside them. That’s how they narrow and widen to limit and increase blood flow. But that muscle layer can also spasm and tighten in a way that disrupts blood flow. That’s called vasospasm.
Think of blood flowing through your blood vessels like liquid flowing through a straw. Squeeze or crimp the straw, and liquid can’t flow through as well or at all. Vasospasm is like the straw crimping or squeezing itself. Because your brain has a very high demand for blood flow, even a minor blood flow reduction can disrupt how your brain works.
Vasospasm can happen because of, or in connection to, many factors and causes. These can either be direct causes or risk factors that increase your chances of developing RCVS. Common examples include:
Pregnancy is the most common factor that causes or contributes to RCVS. More than half of all RCVS cases happen after childbirth (postpartum), especially within the first six weeks. Healthcare providers think it’s related to changes in hormone levels. It can happen even if you didn’t have a pregnancy-related condition like preeclampsia, eclampsia or HELLP syndrome.
Drugs that affect your circulatory system can cause or contribute to RCVS. Examples of drug types that can do this include:
Conditions that affect either your brain or the flow of blood inside it can cause, or contribute to, RCVS. Examples include:
In years past, experts thought RCVS was usually a benign (harmless) condition. However, newer research shows that might not always be the case. Up to 30% of people with RCVS have a minor, lasting loss of an ability, such as lingering muscle weakness or balance difficulties. About 8% of people have a more severe lasting problem.
People with RCVS can also develop more serious complications within the days that follow their initial symptoms. Possible complications include:
Thunderclap headaches can also happen again (recur). These usually happen within a week, but sometimes as much as up to four weeks. Some people also develop a lasting (persistent) headache, but this is usually mild.
Providers diagnose RCVS with a combination of methods. These include:
Imaging scans are often the most helpful tool for diagnosing RCVS. Healthcare providers can use them to “see” inside the head and brain and find issues. Some imaging scans can see blood flow and narrowed blood vessels, while others can show areas that aren’t getting enough blood flow.
Imaging scans that may help with diagnosing RCVS include:
People with RCVS may need to have both a CT and an MRI. A CT scan is faster and can help diagnose or rule out a stroke because it can spot blood vessel blockages inside your brain. That’s crucial because strokes are time-critical, and every minute counts.
An MRI or MRA is often necessary once a healthcare provider rules out a stroke. That’s because an MRI or MRA can show vasospasm as it happens or show any lingering effects after it stops. If CT and MRI aren’t enough, your provider may order more invasive diagnostic imaging, like catheter angiography (a catheter that goes through a blood vessel in your leg and up to your brain).
As the name suggests, RCVS is a very treatable condition. That can involve stopping or removing whatever’s causing the vasospasm (if there’s an obvious cause). Once that’s done (or if that’s not necessary or possible), providers will focus on treating the vasospasm.
The most common medications for treating vasospasm are calcium channel blockers (CCBs). Preventing the cells from using calcium keeps the smooth muscle lining of the blood vessels from flexing and spasming when it shouldn’t. That makes the blood vessels relax and widen, increasing blood flow.
In some cases, healthcare providers may recommend an endovascular procedure. These are procedures that treat narrowed blood vessels from the inside. A provider inserts a catheter into a blood vessel elsewhere in your body (usually your wrist or upper thigh) and then threads it up to your brain.
Once there, providers can use the catheter to inflate a balloon to widen the artery (angioplasty) or deliver drugs directly to the vessels experiencing vasospasm.
The possible complications or side effects depend mainly on the treatment(s) you receive. Your healthcare provider is the best source of information about possible complications and side effects that might affect you. They can also tell you what to watch for and what to do if side effects or complication symptoms appear.
With treatment, most people recover from RCVS within days or a few weeks.
RCVS happens unpredictably, and for reasons healthcare providers don’t fully understand. Because of that, it’s not always preventable. However, you can reduce your risk of developing it.
The best way to reduce your risk of RCVS revolves around nonmedical drug use. That includes drugs that a healthcare provider doesn’t prescribe or prescription drugs that aren’t taken as directed. Always take prescription drugs exactly as prescribed, and avoid nonmedical drug use of any kind.
If you have RCVS, the most likely first symptom will be a thunderclap headache, which is sudden and severe. People describe them as “the worst headache I’ve ever had.” A thunderclap headache is always a medical emergency, and you should dial 911 (or your local emergency services number) immediately if you or someone you’re with has one.
RCVS can also cause symptoms similar to those that happen with a migraine or stroke. It can cause disruptions in how certain areas of your brain work, affecting vision, hearing, ability to speak and understand others, balance and more.
Some people may experience a long-term or permanent loss of abilities. But, with quick treatment, the odds are generally good that you won’t have long-term or permanent issues.
How long RCVS lasts depends on what’s causing it, how quickly you receive treatment and the treatments you receive. Because multiple factors can play a role, your healthcare provider is the best person to ask about what you can expect.
Most (80% to 85%) people have a full recovery with no lasting symptoms. About 10% of people will have lasting minor issues (subtle difficulties with certain abilities).
Unfortunately, RCVS can have severe complications. These are uncommon, but they include life-threatening complications like stroke. Because of this, a quick diagnosis and treatment are very important to increasing your odds of a good outcome.
If you have RCVS, your healthcare provider may recommend ongoing treatment to prevent it from happening again. They may also recommend lifestyle changes to reduce the risk of this condition returning.
Possible changes can include:
If you have RCVS, your healthcare provider will likely recommend scheduling follow-up visits to monitor your symptoms and adjust treatments as needed. Seeing your provider for follow-up allows them to spot early warning signs of RCVS symptoms or complications.
You should go to the emergency room if RCVS symptoms return, especially thunderclap headaches or any stroke-like symptoms. These are always medical emergencies. A “wait-and-see” outlook can be dangerous. Don’t delay getting help.
Questions you can ask your healthcare provider include:
Experts suspect that RCVS is relatively common. It’s most common among AFAB individuals between the ages of 20 and 50.
However, it isn’t easy to narrow down exactly how common RCVS is for several reasons:
A note from Cleveland Clinic
Reversible cerebral vasoconstrictive syndrome (RCVS) is a condition that causes sudden, severe pain and symptoms. It’s a sign that something’s disrupting blood flow inside your brain. The symptoms of RCVS are very difficult to tell apart from those that happen with brain bleeds and strokes, so it’s always important to get emergency medical care without delay.
Like the name suggests, RCVS is very treatable. The best thing you can do if you experience the symptoms is to get emergency medical care immediately. A healthcare provider can diagnose and treat you quickly and avoid dangerous complications.
Last reviewed by a Cleveland Clinic medical professional on 08/28/2023.
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