Monthly archive March, 2015

Reversible Cerebrovascular Vasoconstriction Syndrome (RCVS): when a headache is not “just a headache”

We live in a stressed out society.

With greater pressures to be top performers in terms of productivity in the work place, as parents, as partners or spouses – something usually has to give. I find that one activity that becomes curtailed for many headache sufferers is sleep. “There just aren’t enough hours in the day!” How many times have I heard this statement, or some variation on it, when headache sufferers seek assistance from a neurologist?

Even when headache sufferers are able to achieve eight hours of sleep each night, often the quality is poor. Bedtime is 10PM, with full sleep onset at midnight or 1AM, and then it is time to start the day again at 6AM. Or just as common – a sleep aid medication brings the onset of sleep at 10PM or 11PM, but then at 4AM the person awakens again, fretting over the upcoming demands the new day promises.

I have found that it has become routine for many patients suffering with headaches to write them off, since stress and sleep deprivation so often play significant roles. Perhaps over-the-counter NSAIDs are utilized, and then chronic daily headaches from the overuse of these medications may develop. These may also be discounted, because headaches are present so frequently that pain becomes something to which some grow accustomed.

There is one headache that patients never attempt to explain away though. It it brutal. This headache declares its presence in such a severe, attention-grabbing, dramatic way that it will not allow itself to be ignored by the person suffering from it.

It is known as the thunderclap headache.

As the name suggests, these are unimaginably intense headaches that start very suddenly and with little to no warning, as a clap of thunder might occur quickly after lightning strikes. If a person experiences a headache like this with no prior history of thunderclap headache, a call to 911 (or another emergency service if outside of the United States) is warranted. This headache, until proven otherwise, can occur with subarachnoid hemorrhage, or bleeding in the brain that takes place due to a rupturing/ruptured aneurysm or other abnormal blood vessel.

Emergency medicine providers obtain head CT scans on patients entering the emergency department with complaints consistent with a thunderclap headache. This is taught to medical students as “the worst headache of someone’s life.” CT scans of the brain, while carrying relatively low sensitivity for detecting early ischemic stroke, are quite good at identifying the presence of hemorrhage in the brain. A normal head CT scan and perhaps a lumbar puncture may both be utilized to better exclude that a leaking or ruptured aneurysm in the brain is present. When everything is normal, what then?

The red arrow calls attention to an area of narrowing in the right middle cerebral artery on angiography in a patient with vasoconstriction, or vascular “spasm.” Image source:

Reversible cerebrovascular vasoconstriction syndrome, or RCVS, occurs when arteries within the brain constrict, spasm, or “squeeze,” as I tell patients. When arteries constrict in this way, blood flow can become restricted to areas downstream within the brain. For this reason, there is a risk of ischemic stroke with this syndrome. There is also a risk of hemorrhagic stroke. If the constriction grows severe enough a vessel may rupture. For most patients, though, the syndrome is characterized by the thunderclap headache without stroke. A workup will fail to reveal evidence of an aneurysm or other vascular abnormality, but if imaging of the arteries is performed using catheter angiography, arteries in the brain will appear “kinked,” “narrowed,” or “beaded.” Once symptoms stabilize, if imaging is repeated, the arteries should return to a normal appearance, hence the reversible part of the syndrome. It is only the vascular narrowing that is reversible though. If an ischemic or hemorrhagic stroke has occurred, brain injury is permanent.

Sometimes patients seeking medical care for thunderclap headaches with classic imaging findings for RCVS may be misdiagnosed as having a very rare condition called primary cerebral vasculitis, or primary CNS angiitis. Primary cerebral vasculitis is a condition in which the body’s immune system attacks the arteries of the brain, resulting in stroke. This is treated by suppressing the immune system. I have seen several patients who have been on steroids for presumed cerebral vasculitis, who actually turn out to have RCVS. There is some evidence that steroids may result in worse outcomes for patients with RCVS, so distinguishing between the two entities is very important. The treatment for the two disorders differs greatly.

What causes RCVS? The exact cause of RCVS is unknown, but there are predisposing factors that can be associated with RCVS. Pregnancy and the postpartum state, particularly in women with preeclampsia, can be a trigger for the development of the condition. Selective serotonin reuptake inhibitors (SSRIs), frequently used to treat depression and/or anxiety, have also been associated with RCVS. The use of “vasoactive medications,” meaning medicines that can cause constriction of the arteries, can trigger this as well. This would include triptans, ergotamines (such as DHE for migraine), nasal decongestants that contain ephedrine or pseudoephedrine, certain immune suppression medications used in autoimmune disorders or after organ transplantation, or illicit substances such as cocaine, methamphetamine, ecstasy, and LSD. Cannabis has also been reported in association with thunderclap headaches resulting from RCVS.

RCVS triggers

Identified triggers for the development of reversible cerebrovascular vasoconstriction syndrome. Source: Tan and Flower. Emergency Medicine International, 2012.

Is RCVS a type of migraine? While approximately 40% of patients with RCVS report a history of migraines, thunderclap headaches that occur as part of the vascular constriction are not typical migraines. In fact, triptans that are typically effective in alleviating migraines can actually worsen the narrowing in the blood vessels that is occurring as part of the RCVS thunderclap headaches and should be avoided.

How is RCVS treated? For many patients, RCVS is a self-limited syndrome, and the headaches will stop after several weeks. However, some patients do experience recurrence or ongoing symptoms that may warrant intervention. The first thing that must be done is to remove the trigger, if known, for what may be causing the blood vessels to spasm. If a patient is taking an SSRI, it should be discontinued. Supportive care and pain management through the period of thunderclap headaches may be enough for some patients.  There are no randomized clinical trials to definitively answer the question of how best to treat RCVS, but calcium channel blockers (nimodipine, nicardipine, and verapamil are three such examples from this class) have been utilized with some success in the observational studies that are published. Magnesium may be helpful also, particularly in a pregnant or postpartum patient with eclampsia or preeclampsia.

I have seen this syndrome described as “rare,” but like so many syndromes that may result in stroke in younger patients, I ask myself – rare? Or underdiagnosed? I suspect the latter.

Understanding cerebral aneurysms following the death of journalist Lisa Colagrossi

A reporter for WABC in New York City, Lisa Colagrossi, died over the weekend after an aneurysm in her brain ruptured. Colagrossi, 49, apparently experienced the very sudden onset of symptoms, and was maintained on life support in the neurological intensive care unit at New York-Presbyterian Weill Cornell Medical Center. Unfortunately, despite the care provided, she did not survive.


Layers of the meninges covering the surface of the brain. It is in the subarachnoid space that the major arteries of the brain are positioned, and a ruptured aneurysm results in bleeding along the surface of the brain. Ref:

What happens when an aneurysm ruptures? Where does the bleeding take place within the brain?

The meninges, or the thin tissue coating the surface of the brain, have three basic layers: the dura (outermost layer, which is adjacent to the skull), the arachnoid, and then the pia (adjacent to the brain). When an aneurysm ruptures, typically it is into the subarachnoid space, meaning just beneath the arachnoid layer of the meningeal coating. Thus, a subarachnoid hemorrhage occurs when blood fills the space below the arachnoid layer.

Because the subarachnoid space covers the surfaces of the brain (not just the superficial surface adjacent to the skull, but the deeper surfaces positioned further from the skull as well), bleeding into this space tends to produce a characteristic pattern on a head CT scan that differs from bleeding that is confined the portions of the brain adjacent to the skull (click here for descriptions of other patterns of bleeding from a prior blog post). A head CT scan is a very useful tool in quickly evaluating a patient complaining of symptoms concerning for subarachnoid hemorrhage. The image to the right is a more severe example of this.

What are symptoms that are concerning for subarachnoid hemorrhage? Typically, I use the word “sudden” in describing what occurs. A sudden headache that goes from non-existent to “the worst headache of my life” within seconds, also known as a thunderclap headache, should be urgently evaluated as a subarachnoid hemorrhage (911 call, head CT scan, urgent work up) until it is proven to be otherwise. Sudden loss of consciousness can be consistent with this presentation. Sudden weakness or numbness on one side of the body, as might be seen in any type of stroke, can also reflect a subarachnoid hemorrhage in process. If a head CT scan is normal but the symptoms or history are still concerning for potential ruptured or “leaking” aneurysm, then a lumbar puncture is performed to evaluate for the presence of blood products (blood that is breaking down) in the patient’s spinal fluid. If concern persists, then a catheter cerebral angiogram, a test in which a catheter is threaded through the arteries, typically from the femoral artery in the groin, to image the arteries of the brain closely, may be performed.


A head CT scan from a patient with a ruptured left middle cerebral artery aneurysm. Blood appears white on this form of imaging. Blood is layering along the various inner surfaces of the brain.

What causes aneurysms to form in the arteries of the brain? There are certain situations where genetics play a role, but the majority of ruptured aneurysms and subarachnoid hemorrhages occur in families without a history of similar occurrences. Modifiable risk factors, or activities that place people at risk that can be changed through behavioral changes, include cigarette smoking and chronic alcohol use. Hypertension has also been shown to increase the risk of aneurysm development. Smoking seems to be the universal risk factor, doesn’t it? But yes, cigarette smoking has been demonstrated as increasing the risk for aneurysm formation in the brain in numerous studies at this point.

What should be done if an aneurysm that has not ruptured is found? One of the challenges in evaluating patients with cerebral aneurysms is knowing when to pursue treatment of an aneurysm in the brain, and when to monitor the aneurysm. A common scenario is that of the patient experiencing headaches that turn out to be part of a migraine syndrome, but the headaches lead to imaging of the arteries of the brain. Then, a small aneurysm is identified. Now what? Evaluating this patient population involves weighing benefit against risk. If an aneurysm is quietly present, not causing problems, and the risk of rupture is extremely low, then the risk of a procedure to “fix” the aneurysm is not justified. If an aneurysm is at higher risk of rupture and hemorrhage, then the risk of intervening is outweighed by the benefit in securing the aneurysm and preventing a catastrophic hemorrhage. There are many factors to consider when making a decision about whether to intervene on an aneurysm. The location (the artery affected by the aneurysm) is important, as is size, the patient’s age, and the patient’s medical history.

Unfortunately, Ms. Colagrossi’s passing is another example of how anyone can be affected by stroke, and that a person is never too young to face this diagnosis. If her family and friends come across this at some point, I offer them my sincerest condolences on their loss.