â– LECTURE OVERVIEW: Acute stroke represents a neurological emergency. Timely differentiation between ischemic and hemorrhagic profiles is critical to determine the therapeutic pathway.
â– CLINICAL DYNAMICS:
1. Ischemic Stroke (85% of cases):
- Origin: Caused by thrombotic or embolic occlusion of a cerebral artery, most commonly the Middle Cerebral Artery (MCA).
- Cascade: Focal tissue ischemia triggers an ischemic cascade, depleting ATP, causing cellular depolarization, toxic glutamate release, and ultimate necrotic cell death.
2. Hemorrhagic Stroke (15% of cases):
- Origin: Caused by the rupture of a blood vessel in the brain parenchyma (intracerebral hemorrhage, often from long-standing hypertension eroding Charcot-Bouchard aneurysms) or into the subarachnoid space (subarachnoid hemorrhage, often from a ruptured saccular berry aneurysm).
â– PROGNOSTIC CRITERIA & TIMELINE:
Patient outcome scales correlate heavily with diagnostic staging at presentation, age, pre-existing comorbidities, and biological markers of cellular dividing rates.
â– CRITICAL CARE MANAGEMENT PROTOCOL:
Continuous cardiopulmonary and metabolic monitoring is paramount during acute decompensation. Maintain strict control over fluid ratios and oxygenation parameters.
[HY-BOARD-1089]
🌟 Dynamic Clinical Key:
A non-contrast head CT scan is the absolute first-line screening diagnostic of choice. Because acute ischemia is initially invisible on CT, the main purpose is to rule out hemorrhagic stroke before administering fibrinolytic agents like recombinant tPA, which would be fatal if given during active intracranial hemorrhage. Regularly reassess clinical parameters to adjust long-term therapy. Do not delay airway protection and resuscitation maneuvers for low-priority imaging.