Charcot-Bouchard Aneurysm · What Is It, Causes, and More

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.

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. 

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.

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. 

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.