A patient experiencing an ischemic stroke receives intravenous thrombolytic therapy (tPA) within the therapeutic window. Which mechanism best explains the potential conversion to a hemorrhagic stroke during reperfusion?

💡 Explanation

Reperfusion after ischemia can lead to hemorrhagic transformation because the restoration of blood flow causes matrix metalloproteinase (MMP) activation, which degrades the blood-brain barrier. Therefore, this disruption increases the risk of hemorrhage, rather than the other options which would be neuroprotective.

• An individual with advanced cirrhosis experiences reduced urea production. Which outcome primarily explains why hepatic encephalopathy risk rises as cirrhosis worsens?
• A patient with a thyroid tumor is treated with radioactive iodine, destroying thyroid tissue. Which consequence is most likely due to disrupted endocrine feedback?
• If a 55-year-old individual is prescribed reading glasses due to presbyopia, which mechanism explains why focusing on near objects becomes difficult, despite sufficient light?
• Following a nerve injury, a rehabilitation program aims to restore function. Which mechanism explains why repetitive task practice enhances motor recovery in nervous system?
• During chronic pain management, which process explains why stimulating A-beta fibers can reduce pain sensation in a patient with peripheral neuropathy?
• Why does lymphatic drainage insufficiency typically result in tissue edema rather than rapid toxin buildup in localized regions?