The second meeting of the neurology course-for medical professionals only, we publish it for those interested in joining the course who were unable to attend the meeting Lecture slides: https://jpuedu-my.sharepoint.com/:b:/g/personal/eyad_aqunaibi_jpu_edu_jo/EXF2S-RLatNGjRZE3sOng3UBzJ6ICCfCqDdpEyfuuBjS-w?e=gDaYgL
Due to the abundance of information related to ischemic strokes, this topic will be divided into two lectures. Today, we will focus on the theoretical and fundamental aspects, while next week we will dedicate to discussing clinical cases interactively.
Objectives of this lecture:
A 60-year-old female patient with diabetes and hypertension. While at work, she was suddenly found on the floor with weakness on the right side of her body. Upon arrival of the ambulance and transfer to the hospital, her blood pressure in the emergency room was 210/95 mmHg. The clinical examination revealed weakness in the facial muscles and upper and lower limbs on the right side.
Question: What is the next step? When suspecting a stroke, the first step is to determine whether there is bleeding or not. Therefore, a CT scan of the brain without contrast is performed.
Possible Radiological Results:
In this case, since the weakness is on the right side, we expect the problem to be in the left hemisphere of the brain, as the left part controls the right side and vice versa.
The brain can be likened to a plumbing system; the heart is the pump, and the arteries are the pipes that deliver blood (water) to the brain (trees). Reduced blood flow to the brain is due to two main reasons:
Stroke is the leading cause of disability in America and the fifth leading cause of death. Although ischemic strokes are the most common, hemorrhagic strokes are the most fatal.
The cerebral circulation system is divided into two main sections:
Its source is the internal carotid artery, which branches into:
It consists of the vertebral arteries, which merge to form the basilar artery, ending with the posterior cerebral artery. This circulation supplies the brainstem, cerebellum, and the occipital lobe responsible for vision.
Circle of Willis: A network of arteries where the anterior and posterior circulations meet, providing protection to the brain in case of blockage in one of the main arteries.
Symptoms depend on the affected area:
This scale is used to assess the risk of stroke in patients with atrial fibrillation and determine the need for blood thinners:
Upon arrival of a patient with sudden symptoms:
The drug Tissue Plasminogen Activator is given to patients who meet the criteria:
Important Note: In cases of acute ischemic stroke, we do not immediately lower high blood pressure unless it exceeds 220/120 mmHg, to preserve the perfusion of tissues surrounding the clot (Permissive Hypertension).
In cases of large vessel occlusion in the brain, intravenous thrombolytics (TPA) alone may not be sufficient. In such cases, mechanical thrombectomy is performed to remove the clot, which is an advanced technique that significantly increases the chances of recovery if performed in a timely manner.
Not every case of sudden weakness is necessarily a stroke. There are other medical conditions that may mimic stroke symptoms (Stroke Mimics), including:
Upon admission to the hospital, a series of tests are conducted to determine the cause and prevent recurrence of the stroke:
Recovery from a stroke is an ongoing process that may take a full year or more. The brain cells continue to attempt to build new connections (Neuroplasticity).
Q: Can a stroke present only as memory loss? A: Yes, if the stroke is in the frontal regions of the brain or areas responsible for memory, it may initially be misdiagnosed as Alzheimer's, but the difference is the sudden onset of symptoms.
Q: Why do we not immediately lower high blood pressure in ischemic stroke? A: Because the brain needs high pressure to pump blood through the occluded or narrowed arteries to save the surrounding tissue (Penumbra). Sudden lowering of blood pressure may lead to expansion of the damaged area.
Q: What is the difference between TPA and newer drugs like Tenecteplase? A: TPA has been the global standard for years, but newer drugs like Tenecteplase have shown excellent efficacy and ease of administration, and studies are ongoing to promote their use as a primary alternative.
Q: Does a sudden spike in blood pressure cause thrombotic or hemorrhagic stroke? A: A very sudden and severe spike (Hypertensive Emergency) is often associated with hemorrhagic stroke, while chronic uncontrolled high blood pressure is the primary risk factor for both types.
Conclusion of Part One: This was a comprehensive overview of ischemic strokes regarding definition, causes, and initial management. Next week, we will apply this information to real cases to deepen clinical understanding.
End of Part One.