Ischemic Stroke - Part Two
Meeting Introduction
In the name of Allah, all praise is due to Allah, and prayers and peace be upon the Messenger of Allah. Brothers and sisters, peace be upon you and the mercy of Allah and His blessings. May Allah greet you in this meeting from the series of neurological diseases, in which our esteemed brother Dr. Fawzi Damin Abu Khalil graces us.
Last time, we discussed ischemic stroke from a theoretical perspective, and today the meeting will be practical and enjoyable through the discussion of medical cases (Case Discussion).
Reminder of Causes of Ischemic Stroke:
- Large Artery Atherosclerosis: Such as carotid artery stenosis, accounting for 25%.
- Cardioembolism: Such as atrial fibrillation (AF), accounting for 20%.
- Small Vessel Disease: The primary cause of which is blood pressure, accounting for 25%.
- Other Causes: Such as increased clotting or arterial dissection, accounting for 5%.
- Cryptogenic: Accounting for 30%, and it has been recently found that 10% of these are due to paroxysmal atrial fibrillation (Paroxysmal AF).
Case One: Small Vessel Stroke
Patient Data: A 48-year-old woman suffering from uncontrolled hypertension, diabetes, and anxiety.
Clinical Symptoms:
- Weakness in the face and limbs on the right side (hand and leg).
- Symptoms began the previous evening.
- No numbness, speech is normal, and no other neurological symptoms.
- Blood pressure in the emergency room was 170/90.
Investigations:
- CT Brain: Was normal (to rule out hemorrhage).
- MRI Brain: Showed a small stroke in the left side (Subcortical).
- MRA/CTA: Showed that the large arteries within the brain are open (Patent).
- Carotid Artery Examination: Showed stenosis of less than 50% on both sides.
- Echocardiogram: To ensure there are no clots in the heart or congenital defects.
Diagnosis and Discussion:
Since the weakness is on the right side and the stroke is on the left side, and it is a small stroke, and considering the patient suffers from chronic hypertension and diabetes, this is called Small Vessel Atherosclerosis Stroke (or Lacunar Stroke).
Important Note: In this case, the patient understands and speaks normally because the stroke is "subcortical," while the centers for speech and comprehension are in the "cerebral cortex."
Case Two: Symptomatic Carotid Stenosis
Patient Data: A 66-year-old woman suffering from diabetes.
Clinical Symptoms:
- Sudden loss of vision in the right eye for 15 minutes, then returned to normal (Transient Vision Loss).
- Eye examination by an ophthalmologist was normal.
- Blood pressure 150/90.
Differential Diagnosis:
This condition is called (Amaurosis Fugax), a type of transient ischemic attack (TIA). It is important to distinguish between vision loss due to the eye and vision loss due to the brain; if the patient loses vision in one eye when the other is closed, the problem is usually in the artery supplying that eye (Branch of Carotid).
Investigations and Results:
- MRI/CT: Normal.
- CTA Neck: Showed 70% stenosis in the right internal carotid artery.
- ECHO: Normal.
Treatment Plan:
Since the stenosis is 70% and symptomatic, the optimal treatment is surgery (Carotid Endarterectomy) to open the artery, in addition to medications (aspirin and clopidogrel). Studies show that surgery reduces the risk of future stroke from 26% to 9%.
Case Three: Watershed Stroke
Patient Data: A 54-year-old man suffering from hypertension, diabetes, and high cholesterol.
Symptoms and Results:
- Arrived at the emergency room with very low blood pressure 60/30 due to a heart attack (MI).
- Suffers from weakness on the right side.
- MRI Brain: Showed an extensive stroke at the borders of the main arterial perfusion areas.
- CTA Neck: Showed 60% stenosis in the left internal carotid artery.
Diagnosis:
This stroke is called Watershed Stroke. It occurs when blood pressure drops sharply with pre-existing arterial stenosis, leading to failure of blood supply to the distant areas where the perfusion of the large arteries meets.
Treatment Plan:
Blood pressure should be raised carefully (Permissive Hypertension) to ensure blood reaches the brain, while balancing this with the heart condition.
Case Four: Large Vessel Occlusion
Patient Data: A 48-year-old man suffering from diabetes and hypertension.
Clinical Symptoms:
- Severe weakness on the right side (face, hand, and leg).
- Eye deviation to the left (Gaze Deviation).
- Loss of vision in the right visual field (Right Homonymous Hemianopsia).
- Global Aphasia: The patient does not understand speech and cannot speak.
Clinical Analysis:
The presence of "global aphasia" with right-sided weakness immediately indicates injury to the left middle cerebral artery (Left MCA), specifically in the cerebral cortex. Given that the symptoms are widespread and comprehensive, we expect occlusion in a major large vessel (Large Vessel Occlusion).
Investigations and Results:
- CT Brain: Normal initially (this is common in the first few hours).
- MRA/CTA Brain: Showed complete occlusion (Occlusion) in the left middle cerebral artery (Left MCA).
- MRI Brain: Showed a wide stroke area covering most of the artery's perfusion area.
Treatment Plan:
- TPA: If the patient arrives within the time window (3 to 4.5 hours).
- Mechanical Thrombectomy: Since the occlusion is in a large artery, intervention with a catheter to remove the clot is possible, and it is effective up to 24 hours in certain cases.
- Anticoagulation: If the cause is atrial fibrillation (AF), we do not start anticoagulants (such as warfarin) immediately in large strokes, but we wait from 7 to 12 days to avoid bleeding within the clot (Hemorrhagic Transformation).
Discussion on Medications and Modern Techniques
Alternatives to Anticoagulants (Watchman Device):
In cases of atrial fibrillation (AF), if the patient cannot take blood thinners (due to the risk of frequent bleeding or falls), a device called Watchman Device can be implanted. This device closes the "left atrial appendage" where 95% of clots form, thus protecting the patient from strokes without the need for strong blood thinners.
Modern Anticoagulants (NOACs):
Medications such as (Eliquis) and (Xarelto) have become preferred over warfarin (Warfarin) for the following reasons:
- They do not require regular blood tests (INR).
- They carry a lower risk of cerebral bleeding.
- Their effectiveness in preventing clots is comparable to or exceeds that of warfarin.
- They are not affected by the type of food the patient consumes.
Intracranial Atherosclerosis:
If we find narrowing (but not complete blockage) in the arteries within the brain, studies have shown that the best treatment is intensive medical therapy:
- A combination of aspirin and clopidogrel (Dual Antiplatelet) for a specified period.
- Strict control of cholesterol (Statins) so that LDL is less than 70.
- Regulation of blood pressure and diabetes, and lifestyle changes.
Conclusion and Key Recommendations
- Time is brain: Every minute that passes, millions of neurons are lost, so rapid diagnosis in emergencies is key.
- Permissive Hypertension: In the first 24-48 hours of an ischemic stroke, we allow blood pressure to remain slightly elevated (up to 220/120 in certain cases or 180/105 after TPA) to ensure brain perfusion.
- Accurate Diagnosis: Determining the type of stroke (small vessel, large vessel, or cardiac source) is what dictates long-term treatment to prevent recurrence.
With this, we have completed the second part of ischemic strokes with a review of clinical cases. We thank Dr. Fawzi Damin Abu Khalil for this comprehensive explanation.
Peace be upon you and the mercy of God and His blessings.