What is the management and treatment for a midbrain stroke?

Management and Treatment of Midbrain Stroke

Midbrain stroke requires immediate recognition and urgent transfer to a stroke unit or intensive care facility for comprehensive monitoring and treatment, with management priorities including rapid brain imaging, consideration of reperfusion therapies within appropriate time windows, and close monitoring for brainstem compression. 1, 2

Immediate Triage and Transfer

• Transfer to an intensive care or stroke unit is essential for patients with brainstem strokes to enable close neurological monitoring and access to neurosurgical consultation if needed 3, 1
• Triage to a higher-level center is reasonable if comprehensive care and timely neurosurgical intervention are not available locally 3, 1
• High triage priority with early notification to the receiving hospital ensures selection of a facility with organized stroke unit care 1
• Neurosurgical consultation should be sought early to facilitate planning if the patient deteriorates 3

Urgent Diagnostic Evaluation

Brain imaging must be performed immediately to differentiate ischemic from hemorrhagic stroke and exclude stroke mimics 1, 2

• Non-contrast CT scan is the first-line diagnostic test and should be obtained as soon as possible, certainly within 24 hours 3, 1
• MRI with diffusion-weighted imaging (DWI) is highly useful for detecting midbrain infarcts, which may appear as milimetric diffusion restriction in the mesencephalon 4
• Repeat brain imaging should be considered urgently when a patient's condition deteriorates 3

Essential Laboratory Tests

• Immediate testing should include blood glucose, oxygen saturation, serum electrolytes, and renal function 1
• Routine investigations include full blood picture, electrocardiogram, fasting lipids, erythrocyte sedimentation rate and/or C-reactive protein 3
• Thrombin time or ecarin clotting time should be performed if the patient is on direct thrombin inhibitors 1

Acute Reperfusion Therapies

Intravenous thrombolysis with rt-PA (0.9 mg/kg, maximum 90 mg) should be administered to eligible patients within 3 hours of stroke onset 1, 2, 5

• This therapy is remarkably clinically effective but requires immediate recognition and rapid transfer to hospital 5
• Blood pressure must be lowered to <185/110 mmHg before rt-PA treatment 2
• Mechanical thrombectomy may be considered for patients with large vessel occlusion within 6-24 hours based on advanced imaging criteria 2

Antiplatelet Therapy

• Aspirin (160-300 mg/day) should be started within 48 hours of acute ischemic stroke onset 1, 5
• Starting aspirin within this timeframe results in significant reduction in mortality and morbidity 5

Blood Pressure Management

• Avoid antihypertensive treatment unless systolic BP >220 mmHg or diastolic BP >120 mmHg in patients not receiving reperfusion therapies 2
• Strict blood pressure control is essential during follow-up, as hypertension is a major risk factor 4
• Overly aggressive blood pressure lowering in patients not receiving thrombolysis can worsen outcomes 2

Monitoring for Complications

Midbrain strokes can deteriorate from brainstem compression, requiring vigilant monitoring 1

Clinical Warning Signs

• Depression in consciousness level is a critical sign of deterioration 1
• Glasgow Coma Scale score <12 on admission or a decline of ≥2 points indicates clinical worsening 1
• Factors that exacerbate raised intracranial pressure (hypoxia, hypercarbia, hyperthermia) should be treated 3

Management of Brain Swelling

• Elevation of the head of the bed to 20-30 degrees is recommended to help venous drainage and reduce space-occupying effects 3, 1
• Osmotic therapy with mannitol or hypertonic saline is reasonable for patients with clinical deterioration from cerebral swelling 1
• Mild restriction of fluids is appropriate; hypo-osmolar fluids such as 5% dextrose in water should be avoided as they may worsen edema 3

Prevention of Medical Complications

• Deep vein thrombosis prophylaxis using subcutaneous heparin or low molecular weight heparin is essential for immobile patients 2
• Enoxaparin 40 mg once daily is more effective than unfractionated heparin 5000 IU twice daily 2
• Antibiotics should be administered early to treat infectious complications, particularly pneumonia which is an important cause of death 3
• Body temperature should be controlled, with treatment of fever sources and use of antipyretics 2

Supportive Care and Rehabilitation

• Initial assessment by rehabilitation professionals should occur within 48 hours of admission 2
• Early screening for swallowing difficulties, nutrition, cognition, perception, and communication problems is recommended 3
• Rehabilitation therapy should begin as soon as possible once the patient is medically stable 2
• Piracetam may be considered as adjunctive therapy along with antiplatelet agents 4

Prognosis

Despite being a brainstem stroke, midbrain infarcts carry a favorable prognosis if treated early with strict control of risk factors 4

• Weber's syndrome (ipsilateral oculomotor nerve palsy with contralateral hemiparesis) can show massive clinical improvement within three weeks of medical treatment and risk factor control 4
• The outcome is often good with appropriate management, particularly when there is no evidence of extensive brainstem involvement 3

Critical Pitfalls to Avoid

• Delays in recognition and treatment significantly worsen outcomes, with every 30 minutes of delay decreasing the probability of good functional outcome by 8-14% 2
• Less than 5% of eligible stroke patients receive thrombolytic therapy, mainly due to delayed presentation beyond the 3-hour window 5
• Emergency carotid endarterectomy and immediate EC-IC arterial bypass are not recommended for acute ischemic stroke due to high risk of complications 3, 2