1. Chorionic Villus Sampling - A prenatal diagnostic procedure done around 10-13 weeks of pregnancy to test for chromosomal/genetic conditions (e.g., Down syndrome). Involves taking a small sample of placental tissue.
2. Cardiovascular System - The heart and blood vessel system; a common topic in anatomy, physiology, and medicine.
3. CVS Pharmacy - A major US retail pharmacy chain (formerly Consumer Value Stores).
4. CSV (Comma-Separated Values) - A file format used for tabular data in spreadsheets and databases.
5. Concurrent Versions System - A legacy source code version control system in software development.

• "CVS procedure risks" - I'd cover the prenatal test
• "CVS anatomy" - I'd cover the cardiovascular system
• "CVS stock price" - I'd look up the pharmacy company
• "CVS file format" - I'd explain the data format

CVA - Cerebrovascular Accident (Stroke)

Definition

Epidemiology

• Over 795,000 strokes per year in the United States; 15 million worldwide annually
• Prevalence in persons >65 years: ~60 per 1,000; in >75 years: ~95 per 1,000
• Fifth leading cause of death in the US, but ~75% of stroke victims survive
• Estimated 1 in 200 individuals will sustain a CVA in their lifetime
• Campbell-Walsh-Wein Urology

Classification

1. Ischemic Stroke (~85% of cases)

• Thrombotic - clot forms locally in a cerebral vessel (often on atherosclerotic plaque)
• Embolic - the most common type; emboli (often from carotid artery atherosclerotic plaques) migrate and block smaller intracranial vessels

2. Hemorrhagic Stroke (~15%)

Risk Factors

• Hypertension (most significant modifiable risk factor)
• Diabetes mellitus
• Smoking
• Atrial fibrillation
• Atherosclerosis / hyperlipidemia
• In younger patients: clotting disorders, oral contraceptive use, illicit substances (e.g., cocaine)

Clinical Presentation

Imaging

CT Scan (first-line, urgent)

Fig. - CT scan of ischemic stroke. Arrow shows low-density area corresponding to the infarcted region; the affected brain loses normal sulcal pattern due to edema.

• Early CT may be normal or show a darker low-density area in ischemic stroke
• Identifies hemorrhagic strokes (for which thrombolysis is contraindicated)
• Excludes alternative diagnoses (e.g., tumor)

MRI (better soft tissue resolution, follow-up)

• Acute stroke: bright on DWI + dark on ADC map = restricted diffusion (changes persist ~1 week)
• T2-weighted: bright area representing infarcted tissue
• Better for small strokes missed on CT

Cerebral Angiography

Fig. - Cerebral angiogram of right middle cerebral artery (MCA). (A) Pre-thrombectomy: MCA occlusion visible. (B) Post-thrombectomy: restored flow.

Treatment

Acute Management

• IV tPA (tissue plasminogen activator) - thrombolytic therapy for ischemic stroke; effective if given within 3-4.5 hours of symptom onset; contraindicated in hemorrhagic stroke
• Mechanical thrombectomy - catheter-based clot removal; can be performed up to 24 hours in selected patients
• Supportive care: airway, blood pressure management, glucose control

Post-Acute / Rehabilitation

• Multidisciplinary team: neurologist, physiotherapist, speech & language therapist, occupational therapist
• Antiplatelet therapy (e.g., aspirin) for secondary prevention in ischemic stroke
• Cardiovascular risk factor modification: blood pressure control, statins, smoking cessation, diabetes management

Carotid Endarterectomy

• For significant carotid artery stenosis contributing to embolic stroke risk

Key Complications / Sequelae

• Impaired mobility / paralysis
• Cognitive impairment
• Dysphasia
• Urinary and fecal incontinence
• Depression
• Dysphagia (aspiration risk)
• Death (especially when urinary incontinence present at admission - hazard ratio 2.8 at 3 months)