What are the symptoms and treatment of a pontine infarct?

Pontine Infarct: Clinical Presentation and Management

Primary Symptoms

Pontine infarction presents with a predictable constellation of motor, sensory, and cranial nerve deficits that depend on the specific anatomical location within the pons. 1

Motor Deficits

• Hemiparesis is the most common motor manifestation, occurring in approximately 74% of patients, with severity ranging from mild weakness to severe paralysis 1, 2
• Bilateral motor deficits and tetraparesis occur with bilateral ventrotegmental pontine infarcts 1
• Ataxia affects approximately 26% of patients, particularly with ventromedial pontine involvement 1, 2

Cranial Nerve and Bulbar Symptoms

• Dysarthria is present in approximately 69% of patients, representing one of the most frequent presenting symptoms 2
• Dysphagia occurs in approximately 72% of patients and significantly impacts functional outcome 2
• Diplopia and eye movement disorders affect approximately 16% of patients, particularly with tegmental pontine involvement 1, 2
• Acute pseudobulbar palsy develops with bilateral ventrotegmental infarcts 1

Sensory and Cognitive Manifestations

• Sensory disturbances occur primarily with tegmental pontine infarcts 1
• Cognitive impairment affects approximately 54% of patients and is more common with large lacunar infarcts 2

Anatomical Syndrome Classification

Ventral Pontine Syndrome

• Ventrolateral variant: Mild hemiparesis with minimal tegmental dysfunction 1
• Ventromedial variant: Severe hemiparesis with bilateral ataxia and dysarthria 1
• Approximately 75% of ventral pontine infarct patients show clinical evidence of tegmental dysfunction 1

Tegmental Pontine Syndrome

• Eye movement disorders, cranial nerve palsies, and sensory disturbances predominate 1
• Motor deficits are typically mild 1
• Alternating deficits are rare, occurring in only 11% of isolated pontine infarcts 1

Bilateral Ventrotegmental Syndrome

• Acute pseudobulbar palsy with bilateral motor deficits 1
• Tegmental signs including eye movement abnormalities 1

Critical Warning Signs

Decreased level of consciousness is the most reliable indicator of tissue swelling and clinical deterioration in pontine stroke. 3

Signs of Pontine Compression

• Ophthalmoparesis (abnormal eye movements) 3
• Breathing irregularities and cardiac dysrhythmias 3
• Pupillary abnormalities including anisocoria or pinpoint pupils 3
• Loss of oculocephalic responses 3

Diagnostic Considerations

Imaging Challenges

• Initial CT can be normal in up to 25% of cerebellar infarctions, and similar limitations apply to small pontine lesions 3
• MRI is superior for detecting acute pontine infarction 1, 2

Clinical Course Patterns

• Basilar artery branch disease (44% of cases) is associated with large ventral infarcts, severe symptoms, and progressive or fluctuating course 1
• Small-artery disease (25% of cases) typically produces small ventral or tegmental infarcts with rapidly improving lacunar syndromes 1
• Large-artery stenosis (22%) and cardioembolism (3%) are less common in isolated pontine infarcts 1

Treatment Approach

Acute Management

• Rapid diagnosis and early risk stratification are essential to initiate reperfusion therapy and limit infarct size 4
• ECG monitoring should be initiated immediately to detect life-threatening arrhythmias 4
• Blood sampling for serum markers should be performed but should not delay reperfusion treatment 4

Supportive Care

• Patients should be placed on bed rest while ischemia is ongoing but mobilized when symptom-free 4
• Supplemental oxygen should be administered if arterial oxygen saturation declines below 90% 4
• Continuous ECG monitoring is mandatory during the acute phase 4

Management of Dysphagia

• Dysphagia assessment is critical as it affects 72% of patients and significantly impacts outcome 2
• Enteral feeding may be required in approximately 32% of patients at discharge 2

Prognostic Factors

Favorable Outcome Predictors

• Recovery is good in two-thirds of patients, particularly those with small ventral or tegmental infarcts 1
• Younger age, fewer neurological symptoms, better cognitive function, and preserved swallowing ability predict home discharge 2

Poor Outcome Predictors

• Large ventral infarcts are associated with worse outcomes 1
• Large lacunar infarcts more frequently result in poor cognitive performance, persistent paralysis, and dysphagia 2
• Mean length of acute hospital stay is 24.4 days, with longer stays associated with large lacunar infarcts 2

Hemorrhagic Pontine Lesions

• Primary pontine hemorrhage (hypertensive) carries significantly worse prognosis than hemorrhage from vascular malformations 5
• All deaths in one series occurred in patients with primary pontine hemorrhage versus 5% poor outcomes in cavernous malformations 5

Common Pitfalls

• Classic alternating pontine syndromes are rarely observed in isolated pontine infarcts (only 11% of cases), so their absence should not exclude the diagnosis 1
• Medial and extreme lateral tegmental infarcts are never observed in isolation and suggest larger posterior circulation involvement 1
• Basilar artery branch disease has a propensity for local recurrence, requiring vigilant secondary prevention 1