Charcot-Bouchard Aneurysm

What Is It, Causes, and More

Author:Corinne Tarantino, MPH

Editors:Ahaana Singh,Ian Mannarino, MD, MBA

Illustrator:Aileen Lin, MScBMC

Copyeditor:Joy Mapes

What is a Charcot-Bouchard aneurysm?

A Charcot-Bouchard aneurysm is a rare brain microaneurysm, a bulge in the wall of a tiny (less than 300 micrometers in diameter) artery. It most frequently affects the lenticulostriate branches of the middle cerebral artery, which supply blood to the basal ganglia, thalamus, pons, and cerebellum in the brain. If the bulge bursts, it may cause an intracerebral hemorrhage, or a bleed inside the brain, which can lead to a stroke. This can be fatal; therefore, it requires immediate medical attention. 

The Charcot-Bouchard aneurysm was named after Dr. Jean Martin Charcot and his student Charles Joseph Bouchard, who discovered the aneurysms in the 1800s.

Sometimes, Charcot-Bouchard aneurysms are confused with “berry” or saccular aneurysms, which are the most common type of aneurysm. Unlike Charcot-Bouchard aneurysms, berry aneurysms often occur at branches of medium- to large-sized intracranial arteries and can lead to a subarachnoid hemorrhage, or bleeds surrounding the brain.

What causes a Charcot-Bouchard aneurysm?

A Charcot-Bouchard aneurysm is most commonly caused by chronic hypertension, also known as high blood pressure. High blood pressure creates stress along the walls of blood vessels in the lenticulostriate arteries, which promotes atherosclerosis (i.e., the build-up of fatty deposits in the artery) and increases smooth muscle cell proliferation. Consequently, this makes the blood pressure rise even more and worsens the stress on the blood vessel wall, which can then cause a microaneurysm to form. If the aneurysm ruptures, it results in bleeding and formation of a bruise in the brain. These occurrences are often referred to as hypertensive hemorrhages because the bleeding resulted from chronic hypertension. 

There are several risk factors for developing a Charcot-Bouchard aneurysm. While chronic hypertension is the primary risk factor, there are various lifestyle activities that can add to the risk, including eating a high-fat diet, smoking, drinking excessive amounts of alcohol, and using recreational drugs. Other risk factors include low levels of low-density lipoprotein (LDL), low triglyceride levels, and a high waist-to-hip ratio. People who are older, assigned male at birth, or of Asian or African descent are more likely to develop a Charcot-Bouchard aneurysm than individuals in other groups.

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What are the signs and symptoms of a Charcot-Bouchard aneurysm?

A Charcot-Bouchard aneurysm may not cause any signs and symptoms prior to rupturing. An individual whose Charcot-Bouchard aneurysm ruptures may experience headaches, projectile vomiting, nausea, decreased consciousness, seizures, and a quick, progressive neurological deficit affecting particular areas of the body, such as the right arm or left leg. 

The symptoms an individual experiences may reflect the location of the bleed. For example, if the hemorrhage is located in the thalamus, the individual’s eyes may not move up, down, or to the side, and their pupils may be different sizes. Meanwhile, hemorrhages in the cerebellum may cause vertigo, balance issues, or ataxia and lack of coordination of the gait, limbs, or trunk. Lobar hemorrhages may result in some paralysis, reduced ability to use the senses (e.g., taste or smell), and problems with speech. Hemorrhages in the pons may cause shrunken, pinpoint pupils, weakness in the arms and legs, impaired ability to track objects with the eyes, and sometimes coma. Lastly, an affected putamen may decrease consciousness.

How is a Charcot-Bouchard aneurysm diagnosed?

To diagnose a Charcot-Bouchard aneurysm, a clinical examination -- including assessment of signs and symptoms, medical history, and physical examination -- is necessary. If an aneurysm is suspected, blood tests are often conducted, such as a complete blood count to look for anemia or infection, blood coagulation studies, a lipid panel, electrolyte levels, kidney and liver function tests, and blood glucose and HbA1c levels. In addition, urine toxicology screens are often conducted to determine whether the use of recreational drugs, like cocaine, contributed to the aneurysm. 

Imaging studies may be performed and typically involve a computerized tomography (CT) scan without contrast to detect if there is an intracranial hemorrhage. Other follow-up imaging studies may be conducted, including a CT angiogram, which is a CT with contrast injected, to view blood vessels and tissues. 

If the diagnosis is unclear, a lumbar puncture, which involves the removal of cerebrospinal fluid from the lower back, may be conducted to rule out the involvement of other conditions, like an infection, a subarachnoid hemorrhage, or hemolysis. If an individual presents with neurological symptoms or seizures, an electroencephalography may be performed to measure the brain’s electrical activity. To check for any changes to the heart due to intracranial pressure or damage to autonomic nerves, an electrocardiogram, which assesses the electrical signals in the heart, may also be performed. 

How is a Charcot-Bouchard aneurysm treated?

Treatment for a Charcot-Bouchard aneurysm will vary depending on the symptoms. Typically, an individual seeks medical attention after the aneurysm has ruptured, requiring monitoring in the intensive care unit for at least the first 24 hours. 

When initially presenting to a hospital, the individual’s level of consciousness may be assessed using the Glasgow Coma Scale, a scale from 0 to 15 that considers to what degree the individual is able to open their eyes, use speech, and move. If the individual has a Glasgow Coma score of less than 8, they may need to be intubated. Intubation involves placing a tube down the individual’s throat to assist with breathing. A mechanical ventilator is then attached to the tube to push air through the tube into the individual’s lungs. Depending on the individual’s level of consciousness, sedation may be recommended to accompany mechanical ventilation.

Frequently, blood pressure will need to be lowered to below 140 mm Hg using antihypertensive medications, such as nicardipine, clevidipine, or labetalol. Blood pressure should be lowered with caution in patients to prevent inadequate tissue oxygenation. 

Neurosurgeons, who specialize in brain surgery, are often consulted to determine if there is hypertension in the brain. In the case of intracranial hypertension, intravenous mannitol, which is a diuretic, or hypertonic saline, which is water with a salt content higher than that of the human body, may be given, or the individual may need hyperventilation via a mechanical ventilator. Surgery may be considered to decrease the size of the bruise or stop inflammation from occurring in the brain. 

When ventricles are enlarged or there are signs of neurological deterioration, then a ventriculostomy may be performed. A ventriculostomy is a surgical procedure in which a hole is placed into a ventricle of the brain to drain fluid. 

If an individual has seizures, anti-seizure medications, such as phenytoin may be prescribed.

Many other treatments and interventions may be performed to keep an individual stable after an intracranial hemorrhage. These can include treating high blood sugar with insulin and placing a catheter in the bladder to allow urine to drain out and be monitored.

What are the most important facts to know about Charcot-Bouchard aneurysms?

Charcot-Bouchard aneurysms are rare microaneurysms in tiny branches of the middle cerebral artery that often affect the basal ganglia and lead to hypertensive intracranial hemorrhages. Most frequently, Charcot-Bouchard aneurysms are caused by chronic hypertension, so risk factors include some lifestyle activities and advanced age. Those affected by Charcot-Bouchard aneurysms most commonly present with headaches, projectile vomiting, decreased consciousness, and, occasionally, seizures. Diagnosis is based on a medical evaluation, blood tests, and imaging, typically a CT scan. Treatment is typically initiated after the aneurysm ruptures and involves stabilizing the individual in the intensive care unit and treating symptoms.

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Related links

Intracerebral hemorrhage
Subarachnoid hemorrhage
Saccular aneurysm

Resources for research and reference

Gupta, K., & Das, J. M. (2021, March 8). Charcot Bouchard aneurysm. In StatPearls [Internet]. Retrieved from

Hemphill, J. C., III, Smith, W. S., & Gress, D. R. (2018). Subarachnoid hemorrhage. In J. L. Jameson, A. Fauci, D. Kasper, S. Hauser, D. Longo, & J. Loscalzo (Eds.), Harrison's principles of internal medicine (20th ed.). McGraw-Hill. 

Horn, E. M., Zabramski, J. M., Feiz-Erfan, I., Lanzino, G., & McDougall, C. G. (2004). Distal lenticulostriate artery aneurysm rupture presenting as intraparenchymal hemorrhage: Case report. Neurosurgery, 55(3): 708. DOI: 10.1227/01.neu.0000134561.59093.d7

Papadakis, M., McPhee, S., & Bernstein, J. (2020). Quick medical diagnosis & treatment 2020. McGraw-Hill Education.

Vadera, S., Loh, C., et al. (2021). Charcot-Bouchard aneurysm. In Radiopaedia.