Moyamoya disease

Moyamoya disease is a rare disorder of the carotid arteries - the arteries that supply blood to the brain. The term 'Moyamoya' means 'puff of smoke'. It refers to the appearance of arteries on a cerebral angiogram. The condition was first described in Japan, and, since then has been described in other parts of the world.

What is Moyamoya disease?

In this condition, the carotid arteries that supply blood to the brain become thickened and narrowed gradually over time. As a result, the brain does not receive enough oxygen-rich blood. To compensate for the reduced supply, the body grows new arteries around the head and brain. These new arteries, also called the 'Moyamoya vessels' try to compensate for the reduced blood flow. However, these new vessels never fully compensate for the reduced blood supply. They also have a propensity to bleed easily.

Who does Moyamoya disease affect?

There are no community based studies from India. The prevalence of the disease ranges from 3.2 to 10.5 per 100,000 population. In general, the disease has been found to be more prevalent among Asians and people of Asian origin. The exact cause of this disease is not known yet. About 57% of the affected patients are Asian and 71% are female. Although the disease may be seen in any age group, it is more common in people from 5-15 years and 30-40 years of age. Family history is present in about 10%-15% of the patients.

How does Moyamoya disease present?

All the symptoms of Moyamoya disease arise from reduced blood supply to the brain and/or rupture of the 'Moyamoya vessels'. Reduced blood supply may cause stroke and rupture of the unhealthy Moyamoya vessels causes bleeding within the brain. Adults experience hemorrhage more commonly; cerebral ischemic strokes from reduced blood supply are more common in children.

Children may have weakness or numbness of an arm or leg, hemiparesis, monoparesis, involuntary movements, headaches, dizziness, or seizures. Mental retardation or persistent neurologic deficits may be present.

Adults may have symptoms and signs similar to those in children, but hemorrhage (bleeding) of sudden onset is more common in adults.

How is it diagnosed?

The condition is diagnosed on MRI and cerebral angiography in a patient presenting with stroke or brain bleed.

Are there any associated conditions?

Many conditions are seen more commonly with Moyamoya like condition, although the exact cause-effect relationship has not been demonstrated. Some of the common conditions are

• Radiotherapy to head and neck
• Down's Syndrome
• Neurofibromatosis type 1
• Sickle cell disease
• Congenital Heart Disease

Is there treatment?

Since the exact cause of the disease is unknown, there is no treatment to reverse the narrowing. However, treatment is aimed at preventing stroke by administering aspirin and surgery that improves blood flow to the affected parts of the brain. Surgery is highly successful in preventing stroke and bleeding in future and is the mainstay of treatment.

Without surgery, the majority of individuals with Moyamoya disease will experience mental decline and multiple strokes because of the progressive narrowing of arteries. 

Tips for family and caregivers of patients with Moyamoya disease

Educating and supporting the child and family plays a key role. Not surprisingly, parents are shocked and frightened when they learn their children have had strokes, because they do not realize children can have strokes. Parents should be instructed to inform surgeons and anesthesiologists to avoid hyperventilation. Parents and children need to identify everyday events that may precipitate mini-strokes (also called Transient ischemic attacks). For example, one patient had a stroke while crying or singing a long note during practice. The precipitation of mini-strokes by everyday events is particularly stressful for parents, who may be reluctant to discipline their child for fear of causing a mini-stroke if the child cries. Some sports such as cricket and soccer that lead to hyperventilation, have a high risk of causing mini strokes, and it may not occur to parents to keep their children out of these sports. Schools should be informed about the diagnosis and any restrictions on physical activity. 

Educating the child and family about seizures is an important part of the care of moyamoya patients. As with other seizure patients, families should be told that brief seizures lasting a few minutes are not thought to be harmful, but medical help should be sought for longer seizures.

Emotional support and appropriate advice on pre and post operative care of the patient is an important part of treatment to alleviate the fear, anxiety and uncertainity experienced by the family.

Venous Stroke

'Venous Stroke' or 'Cerebral Venous Sinus Thrombosis' is caused by blood clots blocking the veins in the brain. The veins in the brain drain blood from the brain into the heart. When the veins are blocked, the blood cannot drain normally and causes back pressure in the brain leading to all the symptoms. Although venous strokes account for about 1% of all the strokes across all age groups and about 3/4th of all the strokes in people younger than 50 years.

Causes

Any predisposing condition that leads to increased tendency for blood clot formation, can cause venous stroke. The stroke occurs across all age groups, from infants , pregnant women, cancer patients, patients with blood disorders to elderly patients. Women tend to be more often affected than men.

Predisposing conditions

• Infection
• Trauma
• Pregnancy, puerperium and birth control pill use
• Blood disorders that lead to increased tendency to form blood clots
• Bowel diseases such as Crohn's disease and Ulcerative colitis
• Cancer

Symptoms

1. Sudden weakness or numbness of face, arm or leg; especially if the numbness is all on one side of the body
2. Sudden confusion, trouble speaking or understanding
3. Sudden trouble seeing in one or both eyes
4. Sudden trouble walking, dizziness, loss of balance or coordination
5. Sudden severe headache with no known cause
6. New onset seizures

How is a venous stroke diagnosed?

CT or MRI scans are required to diagnose the stroke. They help to identify the location of stroke and its severity. Occasionally, a cerebral angiogram may be done to confirm the diagnosis. Blood tests may be required to identify the predisposing condition.

Treatment

Heparin is a naturally occurring clot buster. It is the mainstay of treatment in all the patients with venous stroke. In patients with very high pressure in the head, a surgery may be needed to remove a part of the skull. In rare cases, an angiogram and mechanical retrieval of the clot may be needed.

Outcome

In general, the outcome of venous stroke is better than that of arterial stroke if the stroke is treated on time and the predisposing condition is identified and treated. complete recovery is possible in up to 80% of the patients.

What is a Brain AVM?

An AVM (arteriovenous malformation) of the brain is an abnormal tangle of blood vessels in the brain connecting the arteries to the veins. The tangle of abnormal blood vessels is called a 'nidus'. If the arteries and veins are connected one-to-one without the intervening tangle of blood vessels, it is called a fistula. Because these blood vessels are abnormal, they have a tendency to rupture leading to bleeding within the brain. AVMs are not unique to the brain and can occur in other parts of the body. However, brain AVMs are unique in that they cause severe devastating effects if they rupture.

How common are brain AVMs?

Brain AVMs are rare. There are no data from India. Across the world, they occur in about 1 in 100,000 population. About 2% of all strokes are caused due to AVMs. About 2/3rds of people who develop AVMs are under 40 years of age.

Why do they occur?

We do not know why AVMs occur. It is thought that most patients are born with an AVM. But, they are not hereditary. This means people don't inherit AVMs from their parents and don't pass on to their children.

Are there any risk factors for development of AVMs?

There are no known risk factors for the development of AVMs. 

What are the symptoms of a brain AVM?

Majority of the AVMs do not produce symptoms. They are discovered when a CT or MRI is done for an unrelated cause. However, in some patients, AVMs may cause the following symptoms

• Seizures
• Muscle weakness or paralysis
• Loss of coordination
• Difficulties carrying out tasks
• Dizziness
• Headaches
• Visual disturbances
• Language problems
• Abnormal sensations such as numbness, tingling, or spontaneous pain
• Memory deficits
• Mental confusion
• Hallucinations
• Dementia

What is the risk of bleeding from a brain AVM?

The risk of bleeding from a brain AVM is about 1-3% every year. The risk of bleeding also depends upon the type of AVM (fistula, venous malformation, true AVM) and various other factors. Typically, there is 10%-15% risk of death and 20%-30% chance of permanent brain damage related to the bleed.

How are AVMs diagnosed?

Most AVMs are diagnosed with either a CT scan or an MRI. The definitive test to diagnose and plan the treatment of AVMs is cerebral angiography.

How are the AVMs treated?

There are different ways of treatment of AVMs

1. Observation: Sometimes, not choosing any intervention and close observation may be the best treatment. AVMs are generally treated if they cause symptoms or if they have a very high risk of bleed.
2. Surgery: Surgical removal of the AVM is a well established and effective treatment. A successful surgery immediately eliminates the risk of causing any symptoms in future.
3. Embolization: This therapy involves filling up the abnormal arteries with a glue like material from inside during a cerebral angiogram.
4. Gamma knife Radiosurgery: This therapy involves focussed radiation of the AVM in one sitting. However, large AVMs cannot be treated by this modality. Also, the risk of bleeding from the AVM persists for a few months after treatment until the AVM completely closes.

Very often, a combination of the above mentioned therapies may be required to treat AVMs safely and effectively. 

What doctors to consult for a brain AVM?

• Neurosurgeons specializing in vascular neurosurgery
• Interventional Neuroradiologists
• Stroke Neurologists

Diagrammatic representation of  a Brain AVM showing the artery, nidus and the vein

Stroke in Women

The National Commission on Macroeconomics and Health in India Projects about 1.6 million cases of stroke in India by 2015 with death occurring in one-fourth of the cases. Although,gender-wise data are not available for stroke in India, women have a higher incidence of stroke across the world. In the United States, stroke is the fifth leading cause of death in men, whereas it is the third leading cause of death in women. More than half of the new strokes occur in women and one out of every five women with stroke die.

In India, not only are the women less likely to receive medical care, they are also at increased risk of having a stroke because of the following reasons:

1. Pregnancy and High blood pressure: Women are more likely to have a stroke during pregnancy. High blood pressure during pregnancy also places the women at risk of having a stroke even after the pregnancy. Development of diabetes during pregnancy also increases the risk of stroke. Timely treatment of high blood pressure and diabetes during pregnancy helps to mitigate the risk.
2. Birth control pills: Oral birth control pills carry a higher risk of stroke, especially in combination with high blood pressure and smoking.
3. Hormone replacement therapy: Is known to increase the risk of stroke
4. Stroke following child birth is more common in rural India than in the urban setting due to improper aseptic precautions during child birth and dehydration in the mother
5. Improper aseptic precautions during termination of pregnancy by quacks is again more common in rural India than in the urban setting. Infection following termination of pregnancy is a risk factor for stroke
6. Increased prevalence of brain aneurysms (causing brain bleed) in women 
7. Women with Migraines associated with specific symptoms (aura) are associated with increased risk of stroke
8. Higher prevalence of heart disease in women
9. Obesity is twice as common in women than in men in India
10. Lower level of education and awareness among women

Are the symptoms of stroke in women different?

In addition to the typical symptoms of stroke (facial droop, arm or leg weakness and difficulty in speech), women with stroke may experience the following symptoms

sudden face and arm/leg pain

sudden hiccups

sudden nausea

sudden general weakness

sudden chest pain

sudden shortness of breath

sudden palpitations

unresponsiveness

disorientation

confusion

sudden behavioral change

agitation

Having a stroke is one of the most devastating and 'life changing' event. Timely recognition of risk factors for stroke in women is very important so that appropriate steps can be taken to prevent its occurrence. The difference in symptoms of stroke in men and women should also be kept in mind. Finally, the term 'FASTER' should always be remembered in the event of a stroke

F - Face droop

A - Arm or leg weakness

S - Speech difficulty

T - Time from onset of symptoms

E - Early - Seek medical advice immediately

R - Restore - Restore blood supply to the brain

What is 'Aphasia'?

Language is a form of communication that unique to humans. Any disturbance in the ability to speak coherently and meaningfully is one of the most disabling conditions known to mankind. The term 'Aphasia' refers to the language disorder caused by damage to the brain. It is very important for people to know about Aphasia as many patients go undiagnosed and untreated. The Aphasia and Stroke Association of India estimates that aphasia affects an estimated 800,000 to 1,000,000 people annually in India. Since there is no single reporting agency for aphasia and stroke, this number is highly underestimated than the number of actual patients in the country. In a study conducted in Kerala, India, only 10 (8.7%) of the 114 people interviewed had heard of the disability affecting language.

What is 'Aphasia'?

Many structures in the brain are involved in understanding, processing and generating meaningful words. In many right handed individuals, the main areas that control speech are located in the left half of the brain. There are two areas in the brain that control speech, one helps in understanding what is heard and read and the other helps to generate meaningful words. Numerous brain cells connect these two areas so that there is relation between what is understood and what is spoken. In many left handed individuals, the speech areas are located on the left half of the brain; although, in some, they are located in the right half of the brain.

What causes "Aphasia'?

Any damage to the speech areas or the connections can cause aphasia. The most common causes are

• head injury 
• stroke
• brain bleed and 
• tumor.

What are the symptoms of 'Aphasia'?

The symptoms of aphasia depend on the location and extent of damage to the brain. Patients may have a difficulty in understanding spoken or written words when it is called 'Receptive aphasia' as it is a disorder of speech reception. If the patient is able to understand, but cannot speak well, it is called 'Expressive aphasia' as it is a disorder of expression. Patients may have one of these or a combination of 'receptive' and 'expressive' aphasia.

People with Receptive aphasia

• Know that others are speaking to them
• May follow some of the words
• May have a difficulty to put together the words to form a meaningful thought
• May understand hand signs
• Are able to speak meaningful sentences
• May have difficulty reading forms, books and written material

People with Expressive aphasia

• May be able to understand what is spoken
• May be able to speak a few words
• May speak incomprehensible words
• May have a difficulty writing meaningful sentences

Other consequences of Aphasia

• Patients are often frustrated because they are either not able to understand what is spoken or unable to speak meaningful words
• The patient may be unable to communicate his/her symptoms
• Often times, the caregiver may be frustrated because the patients do not understand what is spoken
• In long term, aphasia may have a significant psychological impact on the person and depression.

How is Aphasia diagnosed?

A Neurologist, Neurosurgeon or a Speech and Language Therapist are able to diagnose aphasia and determine the cause. Common tests employed to diagnose the cause of aphasia are CT, MRI, lumbar puncture (to test the spinal fluid). A detailed evaluation by the Speech Therapist may be needed.

How is Aphasia treated?

In many patients, treating the cause of aphasia (such as stroke, brain bleed or tumor) will result in resolution of aphasia. However, the extent to which the aphasia will improve may vary. Many treatments are available for patients with persistent aphasia. Typically, the Speech and Language Therapist administers these treatments to help patients overcome the disability due to aphasia. Apart from these, many computers and mobile phones have applications to help patients with aphasia get around their daily work.

Where can I get more information about Aphasia and its treatment?

Many organizations provide help to the patients and caregivers. Some of these are

1. Aphasia and Stroke Association of India (http://www.aphasiastrokeindia.com/)
2. American Speech-Language-Hearing Association (http://www.asha.org/)
3. National Aphasia Association (http://www.aphasia.org/)
4. American Stroke Association (http://www.strokeassociation.org/STROKEORG/LifeAfterStroke/RegainingIndependence/CommunicationChallenges/Types-of-Aphasia_UCM_310096_Article.jsp)
5. National Stroke Association (http://www.stroke.org/we-can-help/survivors/stroke-recovery/post-stroke-conditions/physical/aphasia)

A Patient's Guide to Cerebral Angiography

What is 'Cerebral Angiography' or a 'Brain Cath'?

It is a procedure which uses a dye (contrast material) and X-rays to visualize the arteries and veins in the neck and brain.

When is it performed?

This test is generally recommended by the doctor to evaluate patients with stroke, brain bleed, aneurysms,vascular malformations and brain tumors.

Who performs the procedure?

A specialist trained in neurointerventions can perform angiography. The specialist may be a neurosurgeon, neuro-radiologist or a neurologist.

How do I prepare for an angiogram?

Before scheduling the procedure, your doctor will check your kidney function and order other blood tests. Please inform your doctor about

1. Your allergies (specifically allergy to shellfish and iodine)
2. History of bleeding gums or easy bruising in the past
3. Your medications (specifically Metformin for diabetes mellitus)
4. Whether you are pregnant
5. You may be asked to not eat and drink anything for about 8-12 hours prior to the procedure

How is the procedure performed?

1. You will be asked to lie on a X-ray table.
2. Your head may be strapped using a tape to keep it still.
3. You may be given intravenous medications for pain and to put you to light sleep.
4. A numbing medication (local anesthesia) is given around the artery in the groin (femoral artery). You may have a transient stinging or burning sensation when the medication is injected in the groin.
5. A long catheter (a catheter is a long slender tube) is inserted through the artery in the groin and passed all the way up to the neck with the help of X-rays
6. Contrast dye is injected into the various arteries in the neck that carry blood to the brain and X-ray pictures taken to visualize the arteries and the veins and the blood flow pattern.
7. A diagnostic angiogram usually lasts about 30-45 minutes depending upon the specific arteries and veins that are being examined.
8. While the dye is being injected, you may feel a warm flushing sensation. You may also experience a metallic taste in the mouth for a few minutes.
9. After the angiogram, the doctor removes the tube from the groin and holds pressure over the artery in the groin to allow blood to clot and seal the hole in the artery.
10. Alternatively, your doctor may use a closure device to seal the hole in the artery.

How long do I have to stay in the hospital after the procedure?

A diagnostic cerebral angiogram is usually performed as an outpatient procedure. You will have to lay flat in the bed for about 3-6 hours after which you may be discharged home.

What precautions should I take after going home?

1. It is recommended not to drive or do any strenuous work for 1-2 days after the procedure. 
2. Do not exercise. 
3. You may walk around in the house. 
4. You may have some soreness in the groin for a couple of days. 
5. You may resume normal daily activity from the next day or the day after. 
6. You may take over-the-counter pain medications, if needed. 
7. If you are diabetic and take Metformin, do not take the medication for 24-48 hours following the procedure.
8. Immediately call the doctor's office if you experience

• severe itching all over the body
• rash over the groin or anywhere in the body
• swelling in the groin
• bleeding from the groin
• slurred speech
• weakness of an arm or leg

What are the risks of Cerebral Angiography?

1. There is a small risk of allergy to the contrast dye. If you have a history of allergy to the dye, your doctor may ask you to take some medications prior to the procedure to prevent any allergic reaction
2. There is a small risk of bleeding from the puncture site in the groin (1%-2%). Alternatively the bleeding may be under the skin forming a 'pseudo-aneurysm'. A swelling may be seen in the puncture site in the groin.
3. In about 0.5%-1% of the patients, a clot from within the catheter or a cholesterol plaque from one of the arteries in the neck may be dislodged and block an artery supplying the brain leading to stroke. With the advent of newer techniques, the incidence of a major or significant stroke following diagnostic angiography in experienced hands is very low.

From 'FAST' to 'FASTER'. The MR CLEAN Stroke trial: What does it mean to us?

The recently published MR CLEAN trial for interventional management of stroke is a major step towards management of acute ischemic stroke. The trial was conducted in Netherlands and compared medical management with medical management and interventional therapy. At the end of three months, a significantly greater proportion of patients in the interventional therapy group had good outcome than those in the medical treatment group (32.6% Vs 19.1%). Good functional outcome was 67% more likely in the interventional group.

This trial included patients with large artery strokes. Patients with large artery strokes have a clot occluding one of the major arteries that supply the brain such as the internal carotid artery or the middle cerebral artery. Such patients have a very high risk of disability and death. The currently approved treatment of such patients is tPA, a drug that is given intravenously and acts on the clot to dissolve it. However, tPA is able to dissolve only one-fifth of the clots. With the use of stentrievers, about 58% of the clots were removed leading to restoration of blood flow within the artery. A 'Stentriever' is a stent, a small wire cage, that is inserted from the groin through a catheter. When it reaches the clot in the brain, it expands and holds the clot. The stent is then pulled along with the clot.

With one person dying of stroke every 36 seconds in India, it is very essential to organize such stroke centers where appropriate treatment of acute stroke is undertaken in a protocol based manner. For, the general practitioners and neurologists, it is very important to collaborate with a stroke center with 24 x 7 availability of stroke neurologists, neurosurgeons and interventionists. Timely referral and treatment of acute stroke within 8 hours of onset of symptoms can potentially reverse the symptoms and prevent long term disability and death. The new phrase to identify and treat acute stroke is FASTER.

F - Face -Asymmetry of face
A - Arm - Arm weakness
S - Speech - Speech disturbance
T - Time - refer the patient to a stroke center immediately
E - Emergency - Treat stroke as an emergency
R - Restore - Restore blood flow in the vessel when appropriate