# Clinical Cases: Cerebral Blood Supply ## Case 1: Middle Cerebral Artery Stroke - Dominant Hemisphere ### Patient Presentation **Demographics:** 72-year-old right-handed female **Chief Complaint:** Sudden onset right-sided weakness and difficulty speaking, last known well 90 minutes ago **History of Present Illness:** The patient was eating breakfast with her husband when she suddenly dropped her coffee cup. Her husband noticed her right arm was limp and she could not speak coherently. She attempted to stand but fell due to right leg weakness. Emergency medical services were called immediately. Her medical history includes hypertension, atrial fibrillation (on warfarin), and hyperlipidemia. Her husband reports she ran out of warfarin two weeks ago and has not refilled it. **Physical Examination:** - Vital signs: BP 178/96, HR 88 irregularly irregular, T 37.0C - General: Awake, frustrated appearing, attempting to speak but producing only garbled sounds - Neurological: - Mental status: Alert; follows simple one-step commands inconsistently; severe expressive aphasia with only stereotyped sounds "ba ba ba"; comprehension appears moderately impaired - Cranial nerves: Eyes deviated to the left; right homonymous hemianopia on visual threat; right facial droop (lower face) - Motor: Right arm 0/5 (plegic), right leg 2/5, left side 5/5 - Sensory: Does not respond to pinprick on right side; responds on left - NIHSS Score: 18 **Workup:** - **Non-contrast CT head:** No hemorrhage; subtle loss of gray-white differentiation in the left insula and lentiform nucleus (early ischemic changes) - **CT angiography:** Complete occlusion of left M1 segment of MCA; ICA patent - **CT perfusion:** Large perfusion deficit with small core (<15 mL) and large penumbra (>100 mL); favorable core-penumbra mismatch - **INR:** 1.3 (subtherapeutic) - **ECG:** Atrial fibrillation with rapid ventricular response **Diagnosis:** Acute left MCA territory ischemic stroke due to cardioembolic occlusion of M1 segment **Treatment:** - IV alteplase 0.9 mg/kg (given within 2.5 hours of last known well) - Emergent mechanical thrombectomy performed with successful recanalization (TICI 3) - Blood pressure management - Aspirin held for 24 hours post-thrombolysis, then initiated - Anticoagulation with apixaban initiated after 7 days (given stroke size) **Clinical Course:** The patient showed dramatic improvement following thrombectomy. By 24 hours, she had 4/5 strength in the right arm and 5/5 in the right leg. Her speech improved to fluent but with word-finding difficulties (anomic aphasia). At discharge on day 7, NIHSS was 4. At 3-month follow-up, she had mild residual right arm weakness and occasional word-finding pauses but was independent in all activities. **Clinical Pearl:** MCA strokes in the dominant hemisphere produce the classic triad of contralateral hemiparesis (face and arm > leg), hemisensory loss, and aphasia. The eye deviation toward the lesion ("eyes look at the lesion" in cortical strokes) occurs because the frontal eye fields that drive conjugate gaze to the opposite side are damaged. Thrombectomy has revolutionized treatment for large vessel occlusions, with number needed to treat as low as 2-4 for good outcomes. --- ## Case 2: Lateral Medullary (Wallenberg) Syndrome ### Patient Presentation **Demographics:** 54-year-old male **Chief Complaint:** Sudden dizziness, difficulty swallowing, and "numbness on one side of face" **History of Present Illness:** The patient was at work when he suddenly felt intense vertigo and nausea. He vomited twice. He noticed his voice sounded hoarse and had difficulty swallowing water. He also felt that the left side of his face was numb and that objects seemed to be tilting to the left. He has a history of hypertension and smokes one pack of cigarettes daily. He denies arm or leg weakness. **Physical Examination:** - Vital signs: BP 168/92, HR 78, T 37.1C - General: Alert, appears uncomfortable, voice is hoarse - Neurological: - Mental status: Alert, oriented, speech is dysarthric but content normal - Cranial nerves: - Left Horner syndrome (miosis, ptosis, anhidrosis) - Horizontal nystagmus with rotatory component, worse looking left - Decreased pinprick and temperature sensation on left face (V2, V3 distribution) - Left palate does not elevate; uvula deviates right; absent gag on left - Left vocal cord paralysis on laryngoscopy - Motor: 5/5 in all extremities - Sensory: Decreased pinprick and temperature on the right arm and leg (spared on left body; affects right side) - Coordination: Left-sided dysmetria on finger-nose-finger; past-pointing to left - Gait: Unable to walk without assistance; falls to left **Workup:** - **Non-contrast CT head:** No hemorrhage or obvious infarct - **MRI brain with DWI:** Restricted diffusion in the left lateral medulla - **MR angiography:** Left vertebral artery dissection with irregular narrowing - **Lipid panel:** LDL 162 mg/dL - **HbA1c:** 6.1% **Diagnosis:** Left lateral medullary (Wallenberg) syndrome from left vertebral artery dissection **Treatment:** - Aspirin 325 mg daily - High-intensity statin therapy - Blood pressure management - Speech therapy for dysphagia (NPO initially, modified diet as tolerated) - Smoking cessation counseling **Clinical Course:** Swallowing function gradually improved, and the patient was able to eat a regular diet by week 3. Vertigo and ataxia improved over 6 weeks. At 3-month follow-up, he had residual mild left-sided facial numbness and occasional vertigo with rapid head movements but was otherwise functionally independent. **Clinical Pearl:** Lateral medullary syndrome produces a characteristic pattern of "crossed" sensory findings: ipsilateral face numbness (descending trigeminal tract) with contralateral body pain/temperature loss (spinothalamic tract). The ipsilateral findings (Horner syndrome, cerebellar signs, cranial nerve IX/X palsy) reflect structures damaged on the same side, while contralateral body sensory loss reflects crossing of the spinothalamic tract below the lesion. Vertebral artery pathology (dissection or atherosclerosis) is the usual cause. --- ## Case 3: Anterior Cerebral Artery Stroke ### Patient Presentation **Demographics:** 68-year-old male **Chief Complaint:** Weakness in right leg noticed upon awakening **History of Present Illness:** The patient went to bed feeling normal last night. When he woke this morning and tried to get out of bed, his right leg felt "heavy" and he fell. He notes the leg is significantly weaker than his arm, which feels "almost normal." His wife describes that he seems "less interested in things" and has not initiated conversation, which is unusual for him. Medical history includes hypertension, diabetes mellitus type 2, and a 40-pack-year smoking history. **Physical Examination:** - Vital signs: BP 156/94, HR 70, T 36.9C - General: Awake, flat affect, answers questions with minimal elaboration - Neurological: - Mental status: Alert, oriented; flat affect with decreased spontaneous speech; follows commands appropriately; no aphasia - Cranial nerves: Intact; no facial asymmetry; eyes midline - Motor: Right arm 4+/5, right leg 2/5, left side 5/5 (leg weakness >> arm weakness) - Sensory: Decreased sensation to pinprick on right leg more than arm - Reflexes: Right leg hyperreflexic with upgoing Babinski; right arm reflexes normal - Gait: Cannot walk independently due to leg weakness **Workup:** - **Non-contrast CT head:** No hemorrhage - **MRI brain with DWI:** Restricted diffusion in the left medial frontal lobe extending along the interhemispheric fissure, including the paracentral lobule (motor and sensory cortex for leg) - **MR angiography:** High-grade stenosis of left A2 segment of anterior cerebral artery - **CT angiography of neck:** Mild atherosclerotic disease of bilateral carotid bulbs, not hemodynamically significant - **Echocardiogram:** Normal; no cardioembolic source identified - **HbA1c:** 8.2% **Diagnosis:** Left anterior cerebral artery territory infarction from intrinsic ACA stenosis/thrombosis **Treatment:** - Dual antiplatelet therapy (aspirin + clopidogrel for 21 days, then aspirin alone) - High-intensity statin - Blood pressure optimization - Diabetes management with goal HbA1c <7% - Physical therapy for gait training and strengthening **Clinical Course:** The patient's leg strength gradually improved to 3+/5 by discharge on day 5. His affect remained flat but improved over several weeks. At 3-month follow-up, he walked with a cane and had 4/5 right leg strength. His wife noted his personality had returned closer to baseline. **Clinical Pearl:** ACA stroke presents with the opposite pattern from MCA stroke: leg weakness greater than arm and face, reflecting the somatotopic organization of the motor homunculus (leg representation on the medial surface supplied by ACA, face and arm on the lateral convexity supplied by MCA). Personality changes and abulia (lack of will/initiative) can occur with medial frontal involvement. The relative sparing of the arm helps distinguish ACA from MCA territory infarction. --- ## Clinical Image ![MCA territory stroke on CT](case_01_image.jpg) **Image Description:** Axial CT scan demonstrating loss of gray-white differentiation in the left MCA territory, representing acute ischemic changes. The insular ribbon sign (loss of insular cortex definition) and obscuration of the lentiform nucleus are early CT findings of MCA territory infarction that may be visible within the first few hours. **Attribution:** Image from Radiopaedia (https://radiopaedia.org/), Creative Commons Attribution-NonCommercial-ShareAlike 3.0 license.