Transient Ischemic Attack and Ischemic Stroke
This week I received an inbox message from Miss. C asking about transient ischemic attack and ischemic stroke, and their management.
“คุณหมอคะ ขอคำแนะนำเกี่ยวกับการดูแลผู้ป่วยเส้นเลือดในสมองตีบให้หน่อยนะค่ะ ขอบคุณค่ะ” This is an absolutely important topic to bring to attention as according to the World Heart Federation (WHF), roughly as high as fifteen million people globally suffer a stroke each year. While there is no denying that this number is shockingly high, however, with more awareness of this condition, by identifying the risk factors and through implementing healthy lifestyle modifications, stroke is very preventable. The pathology of a transient ischemic attack and ischemic stroke in a sense are similar to a heart condition known as myocardial ischemia/myocardial infarction. Similar to myocardial infarction, where there is a mismatch of supply and demand of the blood to the heart (that potentially can cause the cell of the heart to die, a process called necrosis), the same process in the brain through the lack of blood supply can cause death of brain tissues, which depending on the location of the injury can lead to symptoms of: motor weakness, loss of vision, and even aphasia (inability to speak due to the compromising of blood supply to the left frontal lobe of the brain). Both ischemic stroke and transient ischemic attack have the same clinical presentation with some minor differences. Allow me to give an example for a better understanding. Mr. Sompong is a sixty-six-year-old man. He smokes two cigarettes per day and his hobby is watching soap operas. One evening while enjoying his favorite desert of sweet sticky rice and durian with extra coconut milk, he suddenly experiences a weakness on the right side of his body. He can no longer hold onto his spoon and is unable to verbally communicate what is going on with his body to his wife. In a rush, his wife takes him to the emergency room. Miraculously by the time Mr. Sompong arrives at the emergency room all of his symptoms have resolved completely. He is able to communicate, give his medical history, and describe in detail the episode of weakness he experienced. Mr. Sompong experienced an episode of transient ischemia attack. His symptoms lasted less than twenty-four hours and his symptoms resolved completely. Transient ischemic attack occurs when for some specific reason, the brain is not receiving enough blood to a certain part of the brain but luckily there has not yet been any cell death therefore the symptoms usually resolves completely. This episode of transient ischemia attack served as a warning to Mr. Sompong that if he continues his sedentary lifestyle and continues to smoke he may develop a stroke. Symptoms of a stroke will be the same as the example above, however, the episode will last for longer than twenty-four hours and instead of spontaneous recovery of the symptoms patients will most likely have some permanent neurological effects. In a patient with a scenario like Mr. Sompong, it is essential to promptly order a CT scan once they arrive at the emergency department, as this will dictate the medical therapy they will receive. Medical management for hemorrhagic stroke and ischemic stroke are very different to one another therefore a correct diagnosis is a vital first step in patient care. There are two types of stroke: hemorrhagic stroke (caused by the rupture of blood vessels in the brain leading to intracranial bleeding and in turn decreasing blood supply to a specific area of the brain), which accounts for roughly twenty percent of all stoke cases, and the second type, ischemic stroke (usually from emboli interrupting the blood supply of a specific part of the brain), which is the most common of the two, affecting around eighty percent of the cases. After the CT imaging confirms the diagnosis of ischemic stroke in a patient, they are started on thrombolytic therapy in order to break down the blood clot in an attempt to establish normal blood flow to the affected areas of the brain. Thrombolytic therapy should be administered only if the patient arrives to the emergency room within three hours of the onset of symptoms. Anticoagulation medicine such as Aspirin is routinely given to all patients with ischemic stroke and transient ischemia attack such as in the case of Mr. Sompong as Aspirin can prevent subsequent stroke. The next step in management is to search for the cause of stroke. Could it be from the malformation of the structure of the heart, or an abnormality in the cardiac cycle that could cause emboli to block the blood supply to the brain? This is why an echocardiogram as well as an EKG is ordered. Could it be from the narrowing of the carotid arteries (carotid stenosis) in the neck from the plaque building up, which could also develop emboli to the brain? A carotid Doppler is an essential test to order here to investigate. Patients should maintain a healthy lifestyle, such as keeping blood pressure within healthy limits, tight glycemic control for diabetic patients, and keeping LDL lipids below one hundred, and most importantly smoking cessation if the patients are smokers (cigarette smoke causes damage to the blood vessels and plaque that potentially can cause emboli). Patients who have experienced a stroke often benefit from physical therapy, occupational therapy and speech therapy in an attempt to regain and strengthen the neurovascular connection and pathway. Regardless of susceptibility to an ischemic attack or ischemic stroke one should always practice a healthy lifestyle through proper diet, exercise, relaxation techniques, and routine visits your primary care provider.