Center for Stroke and Cerebrovascular Disorders

Defining the Brain Attack

Clogged Blood Vessel
When a blood clot becomes lodged in one of the major blood vessels near the base of the brain, the brain normally supplied by this vessel becomes injured, causing a stroke.

A stroke is an attack of the brain. It occurs when there is interruption of normal blood flow to the brain causing brain cell death and the impairm

ent of functions such as speech, vision, or movement. A brain attack may also cause coma and death. Stroke is the third leading cause of death in the United States after heart disease and cancer. Each year, stroke will strike 500,000 Americans killing 150,000 of them and disabling more adults than any other disease. Although stroke affects more men than women, still more women die each year from stroke than from breast cancer.

Every minute, another American will suffer a brain attack. Four out of five American families will be touched by stroke at some time. Annually, stroke costs the United States $30 billion dollars in medical costs and lost productivity. The risk of African-Americans having a stroke as well as dying from stroke is almost twice that for Caucasians and Hispanics.

Just as a heart attack occurs when an artery to the heart muscle is obstructed, a brain attack or stroke occurs when an artery leading to or within the brain becomes obstructed or ruptures. These brain arteries can be blocked by blood clots (formed in the heart or elsewhere in the body or by the gradual buildup of fatty plaques or deposits, a process known as atherosclerosis. A brain artery ruptures when a weak spot on the blood vessel wall breaks. When the blood supply to a portion of the brain is interrupted, even for a few minutes, brain cells begin to die.

Major Causes of Stroke

Carotid Artery
On the left is a normal carotid artery supplying blood to the brain. On the right, there is obstruction of the carotid artery by fatty deposits.

The carotid artery in the neck is one of the major sources of blood supply to the brain. Due to a variety of causes, including high blood pressure, high blood fat and cholesterol levels, diabetes, smoking and hereditary factors, fatty deposits or plaques may gradually build up within the carotid artery. Eventually, this can obstruct the normal flow of blood to the brain. A special ultrasound examination of the neck can help detect this problem.

Blood clots may develop in the heart because of an abnormal heart rhythm, especially in the condition known as atrial fibrillation. Once a small blood clot is formed, it can leave the heart and enter one of the arteries traveling to the brain, causing a stroke. Blood-thinning medications help reduce the risk of this type of stroke.

In addition to aneurysms, brain blood vessels may burst and bleed as a result of high blood pressure or hypertension, or in some cases, due to collections of abnormal tangled blood vessels known as arteriovenous malformations, or AVMs.

A brain aneurysm is a protruding bubble or sac on a blood vessel caused by a weak spot in the vessel wall that balloons out over time. Aneurysms have thin, weak walls and have a tendency to rupture causing hemorrhage into and around vital brain structures, frequently resulting in a stroke or death.

Method of Treatment

Carotid Therapies:

One method for relieving obstruction of blood flow in the carotid arteries is to surgically remove the fatty deposits causing the blockage. This operation is known as a carotid endarterectomy above left). An alternative to carotid endarterectomy is balloon angioplasty of the narrowed portion of the carotid artery above middle). In this procedure, a plastic tube or catheter with a balloon $is advanced over a guidewire to the site of carotid artery narrowing. The balloon in inflated, widening the flow channel through the area of plaque. A metallic stent may be left in place afterwards to keep the artery open.

One method of removing a blood clot obstructing a brain artery is to advance a tiny tube or catheter through the affected blood vessel to the site of obstruction. Through this catheter, a "clot busting' medicine (thrombolytic agent) can be directly applied to the clot to dissolve it (above left). Once the blockage is relieved and normal blood flow is restored, the brain damage may reverse and a stroke can be avoided (above right). However, this form of therapy, to be effective, needs to be instituted wifhin 6 hours of the onset of stroke symptoms.
* Brain Aneurysm:
An aneurysm of a brain artery may be treated by surgically placing a metal clip on the aneurysm sac thus stopping the flow to it (top right). This prevents future bleeding from the aneurysm. In selected cases, an alternative trearment is coil embolization of the aneurysm. In this procedure, a tiny tube or catheter is advanced through a brain artery and is then inserted directly into the aneurysm sac. In this location, multiple soft platinum coils are deposited within the aneurysm stopping the flow to it.

* Hypertension or high blood pressure
* Cigarette smoking
* High blood cholesterol levels, obesity, physical inactivity
* Heart disease, especially an irregular heartbeat called atrial fibrillation
* Diabetes
* Transient ischemic attacks (TIAs). These are brief attacks that can cause neurologic deficits which resolve over a short period of time, such as temporary blindness in one eye.
* Prior stroke
* Aging
* The incidence of stroke is about 30% higher in men than women
* A family history of stroke
* African-American men and women have a significantly increased risk of stroke compared to Caucasians and Hispanics.

* Numbness, weakness or paralysis of the face, arm or leg, especially on one side of the body.
* Sudden blurred or decreased vision in one or both eyes.
* Sudden and severe headache with no apparent cause, often described as the worst headache of your life.
* Difficulty speaking or understanding simple statements.
* Dizziness, loss of balance, or loss in coordination, especially when combined with another symptom.

If you experience any of these symptoms yourself, or recognize them in someone else, CALL 911 immediately, even if the symptoms only last for a short time. Early treatment ensures the best chance of recovery from stroke. Remember, every minute counts.

* Control your blood pressure.
* Find out if you have heart disease, especially an irregular heartbeat known as atrial fibrillation, and follow your doctor's advice for treatment of your heart disease.
* Find out if you have carotid artery disease. This condition may be treated using either surgery or balloon angioplasty.
* Find out if you have diabetes and follow your doctor's advice on controlling this disease. If you smoke, stop. If you don't smoke, don't start.
* Lower your cholesterol level.
* Limit your alcohol consumption.
* Control your weight.

By following your doctor's advice and controlling your risk factors, approximately 80% of strokes can be prevented.

Trigeminal Neuralgia (TN), or tic douloureux, is a neurological condition characterized by paroxysmal episodes of lancinating facial pain lasting a few seconds. This pain is usually triggered by sensory stimuli such as chewing, shaving, smiling, touching the side of your face, or brushing your teeth.

The trigeminal, or fifth cranial nerve, is the largest cranial nerve and it divides into 3 branches once it reaches the face. They are called V1 (forehead area), V2 (upper lip and cheek), and V3 (jaw region). The pain is usually confined to one or more of these branches on only one side of the face.

Ninety percent of the cases of TN are caused by a normal artery near the brain stem which is in an abnormal position. This artery has a loop in it which is pressed up against the trigeminal nerve. With each beat of the heart, blood is forced through this artery which causes the artery to bump up against the nerve. With time, this repeat pressure rubs the insulation off the nerve. This causes the nerve to fire these abnormal painful electrical-like shocks.

Rarely TN can be caused by tumors, less than 0.8% incidence, or multiple sclerosis, 3% incidence. Most of the other causes of TN are unknown.

First of all, a good history and neurological examination should be performed by a neurologist. The exam is usually normal except for the ability to reproduce the pain by touching the trigger point. Imaging studies, such as an mri scan with contrast, should be performed prior to any treatment in order to rule out a tumor as the cause of the pain.

What treatment options are available and what are their risks and benefits?

There are three categories of treatment options available. They include medical, invasive non-surgical, and surgical.

The initial treatment of choice for TN is the medication called Carbamazepine (Tegretol) or Trileptal. This drug provides complete or acceptable relief of pain in 69% of patients with TN. Tegretol is not a "pain pill". It is most effective by gradually increasing the dose to where it achieves a level in the blood which provides the maximal relief of the symptoms. The maximum daily dose for Tegretol is 1600 mg and 1200mg-2400mg for Trileptal. Side effects include drowsiness, staggering, dizziness, depressed white blood cell count, and liver toxicity. Other pharmacologic therapies, which may help with alleviating the painful episodes include baclofen, pimozide, phenytoin, clonazepam, and amitriptyline. These medications can be used in conjunction with Tegretol or Trileptal but must be closely regulated by your physician. The benefits of this medical treatment option include avoiding the risks involved with the invasive non surgical and surgical treatments.

1. Peripheral Nerve Block
This procedure provides temporary relief of pain by injecting either phenol, or alcohol around the trigeminal branch involved.

2. Percutaneous Stereotactic Rhizotomy (PSR)
The goal of PSR is to injure or destroy the trigeminal nerve via different techniques which may include radio- frequency thermocoagulation or glycerol injection.

In radio frequency heating, an electrode is inserted through a spinal needle under radiographic guidance and certain pain fibers of the trigeminal nerve are destroyed by heat. With this technique there is good pain relief in 80-90% of cases. The major complication is called "anesthesia dolorosa" which is a painful condition that is difficult to treat. When this occurs the patient develops a severe constant burning, aching pain which is more disagreeable than the original pain. This occurs approximately 2 -4 % of the time.

With the glycerol injection a rhizotomy or nerve injury is performed by injecting glycerol in this same area instead of using heat. About 85-90% of patients have a good result - that is, significant relief from TN pain. With this procedure there is a lower incidence of "anesthesia dolorosa".

The benefits of these invasive non surgical techniques is that the patient does not have to accept the risks of "major" brain surgery and the general anesthesia associated with it. Another benefit is that recurrences of pain may be treated by repeat procedure, although the results of repeat procedures may be less successful.

The risks include the above mentioned "anesthesia dolorosa", infection, facial weakness, facial numbness, double vision, reduced hearing, and alterations in lacrimation and/or salivation. It is important to remember that with PSR you are treating the symptoms of TN and not the problem itself. Therefore, the chances of the pain returning with PSR is greater than with the surgical treatment option.

The surgical procedure performed to treat TN is called a microvascular decompression (MVD). The MVD is recommended for patients who have failed medical treatment and are in good health.

With this procedure, the patient is taken to the operating room and a small amount of hair is shaved behind the ear on the affected side. Under general anesthesia, the skin is opened and a small piece of bone is removed. Working under the microscope, the neurosurgeon is able to identify the blood vessel that is pressing against the nerve. The surgeon will then move it out of the way by tacking it up away from the nerve with an insulating sponge. The bone is then replaced and the skin is closed.

The benefits of this procedure involves the fact that the problem itself is treated if in fact the blood vessel is the offending agent. There is an 85-90% initial success rate in longstanding reduction of pain without the need for medications and 70% at 10 years post operatively. This is compared to the 20% success rate at 12 years post-operatively with the PSR. The incidence of facial numbness is also much less then with PSR, and "anesthesia dolorosa" does not occur.

The mortality for this procedure is 1%. The most common complications include mild facial numbness (25% - usually temporary), hearing loss on the affected side (3%), double vision (usually temporary), spinal fluid leakage (5%), and meningitis (less than 5%).

Gamma Knife Radiosurgery (Radiation)

This procedure involves targeting focused radiation to the trigeminal nerve thereby injuring it      enough to keep it from firing the painful electric shocks. It is a good option for someone who has multiple medical problems and cannot safely undergo the general anesthesia required for the surgery. Another patient population that would benefit from Gamma Knife Radiosurgery would be someone who has undergone the brain surgery and no blood vessel was found pressing on the nerve.

There is a 70% success rate in amelioration of pain with or without some continued medication. The lag time between treatment and effect ranges from 5 weeks to 3 months.

For further information or to schedule an appointment please contact the Neurosurgery Clinical Office at (323) 442-572

Cavernous Angiomas (CA); also known as cavernous hemangiomas, cavernous malformations, or cavernomas; are well circumscribed, benign vascular lesions composed of thin walled irregular sinusoidal caverns without intervening neurological tissue.  These lesions differ from arteriovenous malformations in that they do not have large feeding arteries or large draining veins, and their endothelium lining is without the typical elastica or smooth muscle. The vessel walls of the cavernous angiomas may hemorrhage, thrombose, or calcify.  Occasionally, one may present with multiple lesions.  Cavernous Angiomas comprise 10-15% of both intracranial and spinal malformations and are present in 0.3-0.5% of a large autopsy series.

It is felt that these lesions are probably congenital although they may not appear on imaging studies until adulthood after they have had time to become larger.  Enlargement is most commonly a result of small asymptomatic hemorrhages inside the malformation.

Typically these lesions present with hemorrhage, seizure, focal neurological deficit, or incidentally.

       It is estimated that the Cavernous Angioma hemorrhage rate is approximately 0.7-1.7% per lesion per year. Most of these hemorrhages are very small, usually inside the caverns, and may not even produce symptoms. Massive hemorrhages are distinctly uncommon, but hemorrhages outside the malformation (extranidal hemorrhages) are the ones that cause damage.   

It is uncommon to be left with a permanent neurological deficit from a hemorrhage from a Cavernous Angioma unless the lesion is located in the brain stem.

Cavernous Angiomass located in the cerebral cortex may cause irritation of the cortex thereby inducing a seizure. Patients whose Cavernoma presents with a seizure, must be given anti-convulsant medications.

       Focal neurological deficits such as muscle weakness, numbness, double vision, or speech difficulties may also be an indication that one may have a Cavernous Angioma. The specific deficit will depend on the exact location of the lesion.

      Commonly, Cavernous Angiomas are discovered incidentally (without any neurological signs or symptoms).

Cavernous Angiomas are diagnosed by MRI scans and are best seen on the T2 weighted images. Large Cavernomas may be seen on CT scans although this is not the recommended image selection. Small Cavernous Angiomas will most always be missed on CT and very small lesions can even be missed on MRI.

Cerebral  angiograms do not demonstrate Cavernous Angiomas since they are not made up of arteries and veins like arteriovenous malformations (AVM) are.

There are many factors that determine whether or not the lesion should be treated.

In general, lesions that are asymptomatic and incidentally discovered are typically followed with MRI scans yearly for 2 years, then every 5 years thereafter. An MRI should be performed sooner if there is any clinical evidence of hemorrhage or new symptoms. Your physician may or may not decide to give you on anti-convulsant medications.

(i)  Seizure – It is important to achieve complete seizure control with medication. If your seizures are intractable (unable to control with multiple medications), your Cavernous Angioma is in a low risk, easily accessible area of the brain, and your neurologist has performed studies that indicated the lesion is causing the seizure, surgery for resection of the lesion may be indicated. If your seizures are controlled with medication, there may not be a compelling reason to have surgery. Epilepsy alone is not and indication for surgical resection unless the above is true.   

(ii) Hemorrhage – If you have experienced one clinically relevant (neurologically symptomatic) hemorrhage, and your lesion is in a low risk, easily accessible area, surgical removal may be indicated. For lesions in eloquent areas of the brain, surgical removal should be contemplated following the second clinically relevant hemorrhage. We have found that those patients who had a second clinically relevant hemorrhage were more likely to have a third hemorrhage, and the neurological deficit related to the third hemorrhage was much more significant compared to that following the first hemorrhage.

(iii) Progressive neurological deficit – Surgical removal is probably indicated as long as you understand that your specific neurological deficits will most likely be worse after surgery. Chances are good that with time and therapy you will return to your neurological baseline (condition at time of surgery), and may even improve further. Always remember that there are no guarantees. 

The risks of surgery depend on a number of factors including preexisting brain damage from the lesion’s presence, prior hemorrhages, location and size of the lesion, and health of the patient.

Because these lesions can be difficult to completely remove, there is a chance that you may have residual lesion after surgery. Because of the experience of USC’s vascular neurosurgical team, our success rate for complete surgical resection is excellent. Only teams that specialize in this type of surgery can be expected to attain such results.

Stereotactic Radiosurgery using Gamma Knife, Linac, and other modalities have been used in an attempt to treat Cavernous Angiomas without surgery.  Unfortunately the results of such treatment have been very disappointing.  The malformations do not go away.  Further there has been an unusually high incidence of brain swelling after Radiosurgical treatment for some Cavernous Angiomas.  We at USC think that this might be due to the accidental blockage of veins that can be associated with Cavernous Angiomas.  These veins are called Venous Angioma, are not pathological or dangerous n and of themselves, but are important for normal brain blood circulation.  Therefore they must not be blocked or damaged.  It is possible that in some instances Radiosurgery might have blocked these resulting in brain swelling. 

It is possible that your surgeon can give you the names of people who have had to make a similar decision and who would be willing to talk to you regarding their experiences.