Stroke: When the Brain Doesn’t Get Enough Blood

A stroke occurs when the blood supply to the brain is fully or partially blocked. Strokes are caused by either a blockage of a brain artery (ischemic stroke) or by a sudden rupture that causes bleeding in the brain (hemorrhagic stroke). About 85 percent of strokes are ischemic and only 15 % are hemorrhagic. 

1 in 4 people have a stroke in their lifetime. 60 % of strokes happen to people under the age of 70. While the risk of having stroke increases with age, 16 % happen to people under the age of 50. 

In some cases, a transient ischemic attack (TIA) precedes a stroke. A transient ischemic attack (TIA) is often labeled as a “mini-stroke.” It causes the same neurological damage as a stroke, e.g. blurred vision, slurred speech and signs of paralysis. However, most symptoms of a TIA disappear within an hour, whereas the neurological deficits caused by a stroke persist longer than 24 hours. Nonetheless, a TIA should be taken very seriously. It indicates that there is something wrong with the blood supply to the brain and may be a warning sign for an impending stroke. It is, therefore, necessary to undergo a thorough medical checkup if you or someone you know experiences any of the above-mentioned symptoms. In about 30-40 percent of all strokes, a distinct cause cannot be discovered via the usual diagnostic methods. Such cases are classified as cryptogenic strokes.

A variety of symptoms may be a sign of a stroke. Symptoms depend on the affected brain region and the extent of damage to the brain. Usually, one side of the body is affected. Only in rare cases do the symptoms occur bilaterally (both sides). Among others, any of the following symptoms can be observed: 

• Facial paralysis: uneven smile, one side of the face droops 
• Sudden weakness or paralysis in the arms and legs 
• Blurred vision, double vision or blindness 
• Numbness or prickling sensation in the face, legs or arms 
• Loss of balance, dizziness 
• Speech disorders: slurred speech, repeating words or syllables, amnesic aphasia, meaningless or garbled utterances, complete loss of ability to speak. 
• Difficulty understanding people, loss of orientation, general confusion 

A general rule worth remembering is “FAST”: Face drooping, Arm weakness, Speech difficulties, Time to call an ambulance. 

There are also stroke symptoms that are only experienced by women, which is why women who suffer a stroke often get diagnosed later than men: 

• Hiccups 
• Nausea or vomiting 
• Chest pain 
• Fatigue 
• Shortness of breath 
• A racing heartbeat 
• Seizures 

To find out if you are suffering from a stroke, your physician will first check your medical history. This is followed by a neurological examination which will provide first clues about which regions of the brain are impacted and how extensive the damage is. 

A physician will also check if you are having a hemorrhagic stroke (bleeding) or an ischemic stroke (blocked artery). To find out which one you are having, a physician will conduct a CT (computed tomography) and an MRI (magnetic resonance imaging). Knowing which sort of stroke you are having is important because it will influence which therapy you will get. 

In case of an ischemic stroke, contrast medium examination of the brain arteries (angiography) can help locate the blocked arteries.  

It is also important to find out if atrial fibrillation is the cause of the stroke. You can read up on how this is diagnosed here. (link to AF section) 

If no cause for the stroke can be found, your physician might want to implant a small heart monitor (also called ICM) to find out if previously unrecognized atrial fibrillation is the cause. 

In addition, an ultrasound examination of the carotid artery can discover indications of arteriosclerosis of the brain arteries, which can also cause a stroke.

The treatment of the stroke depends on the type of stroke you are having. 

Ischemic Stroke: 

• Emergency intravenous medication that can break up a blood clot.  
• Emergency endovascular procedures to treat a stroke directly in the vessel. 
• Medications are delivered directly to the brain via a thin tube called a catheter. 
• Removing the clot with a stent retriever using a thin tube called a catheter. 
• Removing the plaque blocking a carotid artery by performing a carotid endarterectomy. 
• Angioplasty and stenting help to open and support the artery. Read more about this method here: LINK 

Hemorrhagic stroke: 

• Drugs to countermeasure blood-thinning and to lower blood pressure might be given. 
• Your physician might operate to remove the blood and reduce the pressure on the brain if the bleeding area is big enough. 
• A surgeon might perform surgical clipping by placing a tiny clamp at the base of the aneurysm to stop blood flow to it. 
• A catheter might get inserted into an artery in the groin and guided to the brain. The surgeon will place tiny detachable coils into the aneurysm to fill it. 
• If a smaller arteriovenous malformation is located in an accessible area of the brain physicians might remove it surgically 
• A physician will try to repair blood vessel malformations in a minimally invasive way (for example with highly focused radiation beams).