What are the typical presentation and management of a nondominant Middle Cerebral Artery (MCA) territory stroke in an adult patient with a history of hypertension, diabetes, and other vascular risk factors?

Nondominant MCA Territory Stroke: Clinical Features

Typical Clinical Presentation

Nondominant (typically right) hemisphere MCA territory strokes present with a distinct constellation of neurological deficits that differ markedly from dominant hemisphere strokes, most notably by the absence of aphasia.

Motor and Sensory Deficits

• Contralateral hemiparesis or hemiplegia affecting the face, arm, and leg on the left side of the body, with arm typically more affected than leg 1, 2
• Contralateral hemisensory loss involving all sensory modalities (pain, temperature, proprioception, vibration) on the left side 1, 3
• Pure sensory presentations can occasionally herald large hemispheric infarction, particularly in patients with carotid occlusion 4

Visuospatial and Perceptual Deficits

• Left hemianopia (visual field cut) is common and serves as an independent predictor of severe disability 2, 3
• Left-sided neglect syndrome where patients fail to attend to or acknowledge the left side of space
• Anosognosia (denial of deficit) - patients may be unaware of their left-sided weakness or other impairments
• Constructional apraxia affecting ability to copy drawings or construct objects

Behavioral and Cognitive Features

• Reduced level of consciousness is more common with nondominant hemisphere involvement and predicts malignant course 2, 3
• Acute confusional state may be prominent
• Impaired attention and concentration, particularly for left-sided stimuli
• Emotional lability or flat affect

Risk Factors and Etiology in High-Risk Patients

Vascular Risk Factor Profile

• Hypertension and diabetes mellitus are established stroke risk factors and are correlated in patients with atherosclerosis 5, 6
• These conditions substantially increase cardiovascular disease and stroke risk 6

Common Etiologies for Large MCA Infarcts

• Internal carotid artery (ICA) occlusion accounts for 41% of large MCA territory infarcts 3
• Cardiogenic embolism (particularly atrial fibrillation) represents 54% of cases without ICA occlusion, with atrial fibrillation present in 33% 3
• ICA dissection occurs in 12% of large MCA territory strokes 3
• Small-vessel disease (lacunar) is less common for large territorial infarcts 7

Acute Management Approach

Immediate Diagnostic Evaluation

• Non-contrast CT scan must be completed within 25 minutes of ED arrival to exclude hemorrhage and assess early ischemic changes using ASPECTS score 8, 1
• CT angiography should confirm MCA occlusion location and evaluate collateral circulation status 1, 9
• Calculate NIHSS score to quantify stroke severity; median baseline scores in MCA strokes are typically 16-17 1
• Large infarct cores (ASPECTS ≤6) indicate higher risk of malignant progression and hemorrhagic transformation 9

Reperfusion Therapy

• Administer IV alteplase 0.9 mg/kg (maximum 90 mg) within 4.5 hours of symptom onset if no contraindications exist 1, 9
• Do not delay IV alteplase while arranging endovascular therapy - patients eligible for IV rtPA should receive it even if mechanical thrombectomy is planned 1
• Mechanical thrombectomy is strongly recommended for proximal MCA occlusion with treatment initiation within 6 hours, using stent retrievers as first-line devices 1, 9
• Target TICI 2b/3 angiographic result to maximize probability of good functional outcome 1

Blood Pressure Management

• Maintain BP ≤180/105 mmHg during and for 24 hours after mechanical thrombectomy or thrombolysis 1, 9
• For patients eligible for fibrinolytic therapy, BP must be <185/110 mmHg systolic/diastolic to limit bleeding risk 8
• Avoid antihypertensive agents that cause cerebral vasodilation, as they may worsen edema 1
• Monitor BP every 15 minutes for 2 hours after rtPA, then every 30 minutes for 6 hours, then hourly for 16 hours 8

Antiplatelet Therapy

• Administer aspirin 160-325 mg within 24-48 hours of stroke onset 1, 9
• Delay aspirin for 24 hours if patient received IV thrombolysis to reduce hemorrhagic risk 1
• Clopidogrel 75 mg daily can substitute if true aspirin allergy exists 1

Management of Cerebral Edema and Malignant Infarction

Medical Management

• Elevate head of bed to 20-30 degrees to facilitate venous drainage 1, 2, 9
• Restrict free water and avoid hypotonic fluids to prevent worsening of cytotoxic edema 1, 2, 9
• Correct hypoxemia, hypercarbia, and hyperthermia, as these exacerbate brain swelling 1
• Administer mannitol 0.25-0.5 g/kg IV over 20 minutes every 6 hours (maximum 2 g/kg) or hypertonic saline for clinical deterioration from edema, targeting serum osmolarity of 315-320 mOsm/L 1, 2, 9

Clinical Predictors of Malignant Course

• High stroke severity scores, nausea/vomiting, bilateral ptosis, and nondominant hemisphere involvement predict malignant progression 2
• Early CT hypodensity >50% of MCA territory within 12 hours and hyperdense MCA sign predict neurological deterioration 2
• Reduced consciousness, hemianopia, and complete MCA territory infarction are independent predictors of death or severe disability 3
• Brain swelling is responsible for approximately one-third of deterioration cases, with 10-20% risk in anterior circulation strokes 2

Surgical Decompression

• Decompressive hemicraniectomy reduces mortality by approximately 50% in patients ≤60 years old with malignant MCA infarction 1, 2, 9
• Optimal timing is within 48 hours of stroke onset, before severe neurological deterioration and herniation signs develop 1, 2, 9
• Surgical technique must include bone flap ≥12 cm diameter, extension to temporal skull base, and wide dural opening with duraplasty 1, 9
• For patients aged 60-80 years, surgery may be lifesaving but often results in survival with moderate to severe disability 2
• Early transfer to a center with neurosurgical expertise is recommended for patients with signs of large MCA infarction 9

Critical Pitfalls to Avoid

• Never wait to assess clinical response to IV rtPA before pursuing endovascular therapy - this delays definitive treatment and worsens outcomes (Class III recommendation) 1
• Do not use corticosteroids, furosemide, or hyperventilation for cerebral edema - there is no evidence supporting efficacy in stroke-related edema 1
• Avoid aggressively lowering blood pressure in the acute phase, particularly with vasodilating agents, as this may worsen ischemia 1
• Every 30-minute delay in recanalization decreases chance of good outcome by 8-14% - time is brain 1
• Do not allow availability of intra-arterial thrombolysis to preclude IV rtPA administration in otherwise eligible patients (Class III recommendation) 8

Prognosis and Outcomes

• Mortality is 17% and severe disability is 50% for large MCA territory infarcts, significantly higher than other stroke types 3
• Sixteen of 35 deaths are attributable to brain edema, with patients dying from edema being younger (mean age 57 vs 73 years) and dying sooner (5 vs 37 days) 3
• Patients who develop coma on admission day are more likely to die from brain death 3
• Hemorrhagic transformation risk increases with large infarct size, use of thrombolytic agents, and reperfusion of severely damaged tissue 2, 9