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Friday, January 16, 2015

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

Friday, January 9, 2015

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

    Friday, January 2, 2015

    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)


    Friday, December 26, 2014

    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.




      Friday, December 19, 2014

      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

      Wednesday, December 17, 2014

      Breaking news! Proof of benefit of intra-arterial Stroke treatment!

      In patients with acute ischemic stroke caused by proximal intracranial occlusion of the anterior circulation, intra-arterial treatment administered within 6 hours after stroke onset waseffective and safe.


      http://www.nejm.org/doi/full/10.1056/NEJMoa1411587

      Friday, December 12, 2014

      Brain Aneurysms: What you should know


      What is a Brain Aneurysm?

      A brain aneurysm is a focal bulging of the wall of an artery that supplies blood to the brain. While most brain aneurysms remain silent, a few burst leading to bleed within the brain. The bleed may be so devastating that almost half of the people die and do not reach the hospital. Since most of the aneurysms rupture in the fourth through sixth decades of life, significant part of productive life is lost due to long term disability and death. Hence it is important for the people to know about the symptoms of brain aneurysms and possible treatment options. It is also important for general practitioners to be aware so that they can refer their patients to treatment centers that are capable of managing brain aneurysms.

      What causes Brain aneurysms?

      In most of the people, aneurysms are acquired. This means, that most people with brain aneurysms are not born with these and during their life time, the aneurysms form. High blood pressure, smoking, excessive alcohol intake are some of the risk factors that predispose an individual to aneurysm formation. Women are more likely to develop aneurysms than men and African-Americans and Finnish are more likely to have an aneurysmal rupture than people belonging to other races. An individual with a strong family history (at least 2 close relatives with brain aneurysms) also is a risk factor.

      Rare hereditary conditions such as polycystic kidney disease are associated with brain aneurysms.

      What are the symptoms?

      Most aneurysms do not cause any symptoms. They are discovered incidentally during MRI or CT imaging for an unrelated cause. However, aneurysms can cause symptoms when they burst or occasionally, when they become big in size and press upon the surrounding brain structures. The most common symptoms of aneurysm rupture are


      • sudden severe headache
      • neck pain
      • nausea and vomiting
      • loss of consciousness
      • intolerance to light
      • seizures (fits)
      Other symptoms may include blurred vision, double vision and changes in speech

      How are aneurysms diagnosed?

      There are several tests that the doctor may do to diagnose brain aneurysm rupture. CT scan, MRI, lumbar puncture (in which a needle is inserted in the spinal canal in the back and spinal fluid is drawn to look for blood products) and cerebral angiography. A cerebral angiogram is a test where a catheter is inserted through an artery in the groin and advanced all the way up to the neck. Dye is injected through the catheter and X-ray pictures taken.

      How are aneurysms treated?

      There are two ways in which aneurysms are treated. First, "Clipping", in which the aneurysm is closed from outside with a metal clip through open surgery. Second, "Coiling" in which thin metal threads called 'coils' are inserted in the aneurysm using a catheter in the same way as an angiogram is done. Both these treatment options are complimentary to one another and, depending upon the characteristics, the aneurysm may be suitable for clipping or coiling. If the aneurysm is very small and not ruptured, your neurosurgeon may also recommend observation depending upon the risk of rupture.