What is the management for a patient with an acute infarction of the left pons on a computed tomography (CT) scan?

Management of Acute Left Pontine Infarction

For a patient with acute infarction of the left pons on CT scan, immediately initiate emergency stroke protocols with brain imaging confirmation (preferably MRI with diffusion-weighted imaging if rapidly available), assess for thrombolytic therapy eligibility within the 4.5-hour window, provide supportive care with airway management and blood pressure optimization, and arrange urgent neurology consultation for consideration of endovascular therapy if large vessel occlusion is present. 1

Immediate Diagnostic Confirmation and Advanced Imaging

• CT scan alone has limited sensitivity for acute pontine infarction in the first 24 hours—MRI with diffusion-weighted imaging (DWI) is far superior for detecting acute brainstem ischemia with 88-100% sensitivity compared to CT's poor early detection rate 1, 2

• Obtain MRI with DWI, FLAIR, and gradient-echo sequences immediately if available within 10-15 minutes, as this can be completed in approximately 10 minutes and provides definitive diagnosis of pontine infarction extent 2

• If MRI is unavailable or delayed, proceed with management based on CT findings, but recognize that small pontine infarcts may not be visible on initial CT 3

• Add vascular imaging (CTA or MRA) of the head and neck to evaluate for basilar artery occlusion or stenosis, as this determines eligibility for endovascular therapy even beyond the standard thrombolytic window 1

Acute Reperfusion Therapy Decision-Making

Within 4.5 Hours of Symptom Onset

• Administer intravenous alteplase (rtPA) if the patient presents within 4.5 hours of symptom onset and has no contraindications, as thrombolytic therapy reduces mortality by 21% in acute ischemic stroke with time-dependent benefit greatest within 6 hours 1

• Brain imaging (CT or MRI) must exclude intracranial hemorrhage before rtPA administration—this is an absolute contraindication 1

• Frank hypodensity involving more than one-third of the middle cerebral artery territory on CT contraindicates rtPA, though this is less relevant for isolated pontine infarcts 1

• The presence of early ischemic changes on CT (other than frank hypodensity) does not contraindicate intravenous fibrinolysis 1

Beyond 4.5 Hours or for Large Vessel Occlusion

• If basilar artery occlusion is identified on vascular imaging, proceed urgently with endovascular thrombectomy regardless of time from onset, as patients may benefit from mechanical thrombectomy up to 24 hours with appropriate imaging selection 1, 2

• Perfusion imaging (CT perfusion or MR perfusion) may be required beyond 6 hours to identify salvageable penumbra versus irreversibly infarcted core for endovascular therapy eligibility 2

• Noninvasive intracranial vascular imaging is strongly recommended if intra-arterial fibrinolysis or mechanical thrombectomy is contemplated, but should not delay intravenous rtPA if indicated 1

Immediate Supportive Management

Airway and Respiratory Support

• Assess and secure airway, breathing, and circulation immediately, as pontine infarction can compromise respiratory drive and bulbar function 1, 4

• Provide supplemental oxygen (2-4 L/min by nasal cannula or mask) if oxygen saturation falls below 94%, and monitor continuously 4

• Position the head of bed at 25-30 degrees to optimize cerebral perfusion while reducing aspiration risk 4

• Keep the patient NPO (nothing by mouth) until swallowing can be formally assessed, as pontine lesions frequently cause dysphagia 4

Blood Pressure Management

• Do not routinely treat hypertension unless blood pressure exceeds 220/120 mmHg in patients not receiving thrombolytic therapy—permissive hypertension maintains cerebral perfusion in acute ischemic stroke 4

• If the patient receives rtPA, maintain blood pressure below 185/110 mmHg before administration and below 180/105 mmHg for 24 hours after treatment 1

• Avoid rapid or excessive blood pressure lowering, as this may exacerbate cerebral ischemia in the penumbral zone 4

Neurological Monitoring

• Perform standardized neurological assessment using the National Institutes of Health Stroke Scale (NIHSS) to document baseline severity and monitor for progression 4

• Monitor closely for progressive motor deficits, which occur in 25.8% of pontine infarction patients, particularly with lower pons involvement 5

• Check vital signs at least every 30 minutes during initial evaluation, with continuous cardiac rhythm monitoring 4

• Aggressively treat hyperthermia (temperature >99.6°F), as fever is associated with worse stroke outcomes 4

Essential Laboratory and Diagnostic Studies

• Obtain blood glucose measurement immediately to rule out hypoglycemia as a stroke mimic 4

• Complete blood count with platelet count, prothrombin time/INR, and activated partial thromboplastin time are necessary before any antithrombotic therapy 4

• Cardiac monitoring and ECG are essential, as cardiac arrhythmias commonly accompany acute stroke 4

Antiplatelet and Anticoagulation Therapy

• Administer aspirin 160-325 mg orally within 24-48 hours of stroke onset if the patient does not receive thrombolytic therapy, as aspirin reduces early stroke recurrence 1

• Do not administer aspirin within 24 hours of rtPA administration due to increased hemorrhage risk 1

• Anticoagulation is generally not recommended in acute ischemic stroke unless specific indications exist (e.g., cardioembolic source with high recurrence risk), and only after hemorrhage is definitively excluded 4

Location-Specific Prognostic Considerations

• Lower pontine infarcts carry 3.8-fold increased risk of progressive motor deficits compared to upper pontine lesions, likely due to corticospinal tract involvement and potential for ischemic degeneration 5

• Medial pontine tegmental infarcts may present with prominent sensory symptoms mimicking hemispheric stroke, including pure sensory syndromes or cheiro-oral patterns 6

• Dorsolateral pontine infarcts can mimic peripheral vestibular disorders (vestibular neuritis) with isolated vertigo, potentially leading to misdiagnosis 7

• Female sex and previous hypertension are associated with increased risk of progressive motor deficits in pontine infarction 5

Critical Pitfalls to Avoid

• Do not rely solely on CT scan for excluding pontine infarction—CT has very poor sensitivity for acute brainstem ischemia in the first 24 hours, and MRI-DWI is essential for definitive diagnosis 1, 2, 3

• Do not delay thrombolytic therapy to obtain advanced imaging beyond what is necessary to exclude hemorrhage and confirm ischemic stroke 1

• Do not assume isolated vertigo or sensory symptoms exclude pontine infarction—these presentations are common with specific pontine locations 6, 7

• Do not aggressively lower blood pressure in acute ischemic stroke outside of thrombolytic protocols, as permissive hypertension maintains collateral perfusion 4

• Recognize that basilar artery stenosis may be present (17.9% of pontine infarct patients) but does not independently predict progressive motor deficits 5