STROKE
Definition: A syndrome of focal or global neurologic deficit that develops suddenly and lasts more than 24 hours in a person with no history of recent head injury. If < 24 hours, it is called a transient ischemic attack (TIA). Strokes can be categorized as ischemic (embolic or thrombotic) or hemorrhagic(intracerebral or subarachnoid). Main risk factors for stroke in Africa are hypertension (#1), DM, hypercholesterolemia, smoking, atrial fibrillation, rheumatic heart disease, sickle cell anemia, Age-more than 60yrs, Race, Gender and HIV.
Differential Diagnosis: space occupying lesion (neoplasm or infectious), trauma (subdural or epidural hematoma), toxins (including medications), hypo/hyperglycemia, electrolyte abnormalities (ex hypo/hypernatremia)
ISCHEMIC STROKE:
Epidemiology/Natural History: More common and accounts for 85% of all strokes. Usually occurs in elderly patients except in cases of sickle cell anemia or rheumatic heart disease. Mortality rate is low in the first week (10-20%) but many patients will die of complications in the first 1-2 months including: aspiration pneumonia, septic decubitus ulcers and DVT.
Etiologies:
-Thrombotic – usually related to atherosclerosis
-Embolic – as with atrial fibrillation, rheumatic heart disease or endocarditis
- Paradoxical Embolization is a rare type of stroke where a DVT traverses from the right to left heart via a septal defect and embolizes to the brain
-Shock.
-hypovolemia.
Symptoms and Signs: The most common symptoms/signs of stroke are hemiparalysis, aphasia and coma.
Signs and symptoms of ischemic strokes are variable depending on the artery and part of the brain that is affected. For example:
Anterior Cerebral Artery - Hemiplegia (leg>arm); Confusion, urinary incontinence, primitive reflexes
*Middle Cerebral Artery* (Most Common) - Hemiplegia (face/arm>leg); hemianesthesia; aphasia (if dominant hemisphere)
Posterior Cerebral Artery - Thalamic syndromes with contralateral hemisensory disturbance
Lacunar (involving internal capsule)- Pure hemiplegia
Physical Exam: Perform a close cardiovascular exam for rhythm, murmurs, carotid and subclavian bruits; look for signs of peripheral emboli such as Janeway lesions or splinter hemorrhage. Do a complete and thorough neurological exam.
Diagnostic Studies:
-Most important: urgent noncontrast head CT if available (will help differentiate between ischemic vs hemorrhagic stroke)
-blood work should include at least a HIV Test, CBC, creatinine, lipids, glucose and electrolytes (to r/o electrolyte imbalance or hypoglycemia as cause of symptoms); PT/PTT if you are considering a hemorrhagic stroke as you may want to reverse coagulopathies
-Consider EKG
-Consider carotid dopplers if available
-Consider TTE if available (to look for vegetations or thrombus)
Treatment:
-consider thrombolysis (if available) if onset of symptoms is within 3 hours, there is a large deficit, and there is no evidence of hemorrhage or other contraindications to lysis
· We usually do not perform lysis in our setting.
-start ASA 150mg daily x 30 days (only if can r/o hemorrhagic stroke by CT)
-BP should not be lowered in the first 48 hours unless it is very severe (SBP >200)
· After 48 hours, lower blood pressure slowly
-start statin (simvastatin 20mg)
-start ranitidine or a PPI to prevent stress ulcers
-start subcutataneous heparin to prevent a DVT (if can rule out hemorrhagic bleed)
-change position every 4-6 hours to prevent decubitus ulcers
-keep the head of the bed elevated to prevent aspiration
-watch for signs of cerebral edema/elevated ICP (usually peaks at 3-4 days post stroke); if evidence of elevated ICP (like declining GCS or papilledema) start mannitol
-after 48 hours, start Physical Therapy! Physical therapy is very important in stroke management. It should be started early and continued for at least 2-3 months.
HEMORRHAGIC STROKE:
Epidemiology: Less common (15%) but more severe. Usually occurs in elderly patients or middle aged patients with severe hypertension. Patients often present with coma, headache and/or vomiting. Otherwise, symptoms are similar to ischemic stroke (see above). Almost 50% mortality in the first week. More of these patients will be referred to hospitals like BMC due to the severity of their stroke.
Etiologies:
-Intracerebral (ICH): usually associated with HTN, sometimes coagulopathy
-Subarachnoid Hemorrhage (SAH): RARE; ruptured aneurysm, trauma
Clinical Manifestations:
-ICH: sudden impairment in level of consciousness, vomiting, +/- headache, may see progressive focal neurologic deficit depending on site of bleeding
-SAH: severe headache, nausea and vomiting, often described as ‘thunderclap’, can see nuchal rigidity (blood is a meningeal irritant), impairment in level of consciousness
Physical Exam/Diagnostic Studies:
-similar to exam/workup for ischemic stroke
-consider an LP to check for xanthochromia if you are suspicious for SAH
Treatment:
-reverse any coagulopathies
-BP control with goal of SBP 140-160 to prevent further bleeding
-ranitidine to prevent stress ulcers
-consider nimodipine (a CCB) and phenytoin if suspect SAH as they decreases the risk of vasospasm and seizure in these patients
-change positions, raise head of bed and start physical therapy as in ischemic stroke
Case #1 (Ischemic Stroke)
A 65 yo M is brought in by his family after he was noted to have left sided weakness and slurring of his words.
-What is your impression?
-What is the definition of stroke?
-What are the risk factors for stroke (which you would ask about)?
-What is the most likely type of stroke in this patient?
-What are the types of ischemic stroke?
-What differential diagnoses would you consider?
The patient and his family are unsure but they think the symptoms began about 24 hours ago. The patient denies any fever, headache or changes in his vision. He does not have any chest pain or dyspnea.
Past medical history is significant for HTN and DM.
On exam he is afebrile with a BP of 170/90 and HR 85. He is awake and alert and following commands. He has a left facial droop and is mildly dysarthric. He has 5/5 strength on his right but 3+/5 strength on his left upper extremities and and 4/5 strength in his left lower extremities. Sensation is intact. Reflexes are brisk but symmetric. He has no meningeal signs. Fundoscopic exam reveals no papiledema. Cardiac exam is normal. He has no carotid bruits. Lungs are clear.
-What investigations do you want to order?
-What part of the brain is effected?
You admit the pt to the ICU. You order a FBP, creatinine, RBG, lipid panel, EKG and noncontrast head CT. While you think that the patient likely had an embolic stroke you hold off on starting ASA until you can rule out a hemorrhagic stroke definitively with the CT scan. You decide to keep the blood pressure as is. The patient’s RBG is 9.3. The EKG reveals LAD and LVH but no ischemic changes. The CT results return and are consistent with an ischemic lacunar infarct of the right internal capsule and also involving the right lobe. The rest of the labs are pending.
-What is the most likely etiology of ischemic stroke in this patient?
-What treatments will you initiate?
You start the patient on ASA, simvasatin, ranitidine and sub-q heparin. You order the patient for physical therapy. The rest of the patient’s labs return back normal. The patient’s speech and strength begin to improve after several days in the ICU and he shows no signs of increased ICP. You decide to transfer the patient to the floor with plans to eventually start him on antihypertensives and continue his physical therapy
Case #2
A 42 yo F with HTN is brought in by her family after a witnessed collapse and loss of consciousness that occurred 6 hours ago. Just before collapsing the patient had complained of headache. She vomited once, and then collapsed. She has not other medical problems and is not on any medications.
-What is your impression?
-What type of stroke does this patient likely have?
-What are the 2 kinds of hemorrhagic stroke?
-What risk factors would you ask about for this type of stroke?
The patient is brought to the ICU. On exam she is afebrile, her BP is 190/100, HR 85. She is unconscious and does not open her eyes to voice. She occasionally moans. Pressure on her nailbed elicits flexion of her arm. Her neck is stiff. Pupils are equal, round and reactive. Fundoscopic exam does not reveal papiledema. Heart and lungs are clear. You order a FBP, creatinine, rapid test, lipid panel, EKG. You are informed by your chief that the CT scanner is not working.
-What is the patient’s GCS?
-How do you want to treat this patient?
You calculate the pt’s GCS as 6. You suspect that the patient had a subarachnoid hemorrhage. You decide to treat her with IV hydralazine to bring her blood pressure down and also start nimodipine and phenytoin. You perform an LP to rule out meningitis (although it is lower on your differential) and to check for xanthochromia. EKG reveals deep T-wave inversions in all leads. Her labs are all normal and her rapid test is negative. You continue to monitor the patient in the ICU and after several days the patient’s GCS begins to improve.
