Unveiling The Mysteries Of Reversible Cerebral Vasoconstriction Syndrome (Rcvs): Understanding, Diagnosis, And Management

Introduction

Reversible cerebral vasoconstriction syndrome (RCVS) is a health condition where the blood vessels in the brain contract and relax, leading to a spectrum of symptoms ranging from mild to severe.¹ Various factors, including medications, physical stress, and childbirth can cause this condition.

Although the symptoms are often isolated to a severe ‘thunderclap’ headache that resolves over time, serious complications can develop if RCVS is not promptly recognised and treated. For this reason, it’s essential to understand RCVS so diagnoses and treatment can be done early.

Causes

RCVS is thought to be caused by short-term disturbances in the regulation of blood vessel tone or diameter in the brain. It can occur without an obvious trigger, but doctors can pinpoint a cause in 25% to 60% of people. Some of the known causes include:²

• Certain medications that affect blood vessels including some over-the-counter drugs for colds and migraine treatments
• Childbirth is a common cause of RCVS which accounts for around 50% to 60% of cases, typically appearing within one to six weeks after a normal birth
• Marijuana and antidepressant use

RCVS can also be caused by a variety of other factors such as

• interferon treatment 
• diet pills
• painkillers (such as NSAIDs)

and substances like

• alcohol
• amphetamines
• cocaine
• ecstasy
• and nicotine

Medical events or treatments like

• blood transfusions
• certain hormone treatments
• and surgeries on the head and neck can also play a role

Some other medical conditions have been linked to RCVS, including:

• HELLP syndrome (Hemolysis, elevated liver enzymes and low platelets), a severe form of pre-eclampsia
• antiphospholipid antibody syndrome
• and thrombotic thrombocytopenic purpura

After exposure to a trigger, the onset of RCVS can vary from a few days to several months.^2,3

Epidemiology

We don’t know how many people have RCVS because diagnosing quickly and accurately is hard, but doctors believe it’s common. RCVS usually occurs in adults between 20 and 50 years old, but it has also been seen in some children and teenagers.⁴ 

About 2.5 times more people assigned female at birth than people assigned male at birth develop RCVS. When people assigned male at birth get RCVS, they tend to be about a decade younger than people assigned female at birth when they first experience symptoms.

Symptoms and triggers

RCVS usually develops quite quickly over a month and then stabilises.^3,5 The symptoms usually appear once and can vary widely in intensity. They can range from just headaches to seizures, strokes, and non-aneurysmal subarachnoid haemorrhage. The most severe cases involve bleeding, blockages, swelling of the brain and even death. 

The main symptom is an intense headache, which is often the only symptom. The severe headaches that characterise the syndrome are known as ‘thunderclap headaches’. These develop suddenly and reach their maximum intensity in less than a minute.

The pain is like that which is caused by a burst aneurysm and is so severe that it can lead to screaming, crying, confusion, and even make an individual collapse. While the pain is usually felt on both sides of the head and starts at the back before spreading, it can occasionally be one-sided. 

Unlike the prolonged pain caused by a ruptured aneurysm, the intense headaches in RCVS usually last from one to three hours.⁶ Patients often experience multiple attacks – usually around four throughout one to four weeks. Milder headaches may continue between these severe episodes.

Triggers for these headaches can vary widely, including sexual activity, physical exertion, emotional stress, and even actions like coughing, sneezing, or bending down. Typically, the worst headache occurs about a week after the first one, and all significant headaches generally end within three weeks.

Some people develop headaches that are less severe or gradual. It’s quite rare for someone to experience other symptoms without headaches.⁶ If the patient also has neck pain, it is important to test a tear in the arteries of the neck. Up to 43% of people with RCVS report temporary or persistent symptoms such as visual disturbances, speech difficulties, or muscle weakness.

These can last from a few minutes to a few hours and somewhat resemble those seen in minor strokes. In rare cases, these can lead to permanent issues like paralysis, speech loss, or partial blindness.

Physical exams usually seem normal unless RCVS is occurring alongside conditions like eclampsia or severe infections, which might complicate the situation. During intense headaches, about one in three patients experience high blood pressure, either due to the pain, the syndrome itself, or a related health condition.

Diagnosis

Doctors should suspect RCVS in patients who experience a sudden, severe headache, especially if it happens repeatedly. Other conditions to rule out include bleeding from an aneurysm in the brain, bleeding within the brain itself, clots in the veins of the brain, tears in the arteries of the neck or brain, and bleeding into the pituitary gland.⁷

RCVS often gets confused with a condition called primary angiitis of the central nervous system (PACNS). People with RCVS are usually younger (around 43 on average) than people with PACNS (around 51 on average), and RCVS affects more people assigned female at birth.

Triggers like certain medications or stressful events are commonly found in RCVS but rarely in PACNS. While headaches are common in both conditions, those with RCVS usually experience very sudden and intense headaches that come back, whereas in PACNS, fewer people report this kind of headache.

Diagnosis mainly relies on imaging tests like CT scans or MRIs. These tests are crucial for differentiating between RCVS and PACNS. For instance, initial scans show abnormalities in 70% of RCVS cases compared to nearly all PACNS cases.

Brain damage from lack of blood flow is more common in PACNS, while certain types of brain swelling and minor bleeding are more typical of RCVS. A specific MRI finding, known as the hyperintense artery sign, shows up in many RCVS cases but is rare in PACNS.

An angiogram, which looks at the arteries, is key for diagnosing RCVS. It typically shows more extensive, symmetrical, and severe narrowing and dilation of the arteries in RCVS compared to the uneven, patchy narrowing seen in PACNS. The middle, front, and back cerebral arteries are most often affected in RCVS but it can involve almost any artery.

Testing the cerebrospinal fluid, which surrounds the brain and spinal cord, doesn't usually help diagnose RCVS because the test results are often normal or show only mild, vague abnormalities.

Management

While no controlled studies have looked at RCVS treatments, doctors usually make decisions based on expert advice and case studies. It's important to stop taking any medications that might trigger RCVS, including certain antidepressants, decongestants, and recreational drugs like THC.

Calcium channel blockers, such as nimodipine, nifedipine, or verapamil, are often used to treat RCVS. For example, nimodipine is typically given intravenously at a rate of 1-2 mg per hour, followed by an oral dose of 30-60 mg every four hours for about 4-8 weeks.

Doctors might use a technique called transcranial colour Doppler to check how fast blood is moving in the brain arteries and see how well the treatment is working. Reports suggest that these treatments are successful in 40% to 80% of cases.⁸

In more severe cases, endovascular treatments like balloon angioplasty or the direct injection of vasodilators into the arteries (with drugs like nicardipine, papaverine, milrinone, and nimodipine) have been used. These methods can quickly relieve the narrowing of the arteries seen in RCVS.

Importantly, these treatments don’t work for conditions that look like RCVS but are something else, like vasculitis or atherosclerosis, making them useful for confirming an RCVS diagnosis. Since RCVS typically resolves on its own, the use of these aggressive treatments is generally reserved for confirming the diagnosis in uncertain cases. 

Summary 

• RCVS represents a serious health issue that is quite easy to resolve despite its sometimes dramatic symptoms
• Understanding its triggers and the conditions it can mimic is crucial for accurate diagnosis and effective treatment
• While imaging is important in differentiating RCVS from other serious neurological conditions, treatment primarily revolves around managing symptoms and mitigating triggers, particularly using calcium channel blockers and targeted endovascular interventions
• RCVS must be recognized by healthcare providers early on as a timely and correct diagnosis can significantly impact a patient’s outcome
• Researchers hope to refine diagnostic techniques and treatment protocols, improving care for those affected by this often under-recognised condition