Makindo Medical Notes

Related Subjects: |Anatomy the Medulla Oblongata |Anatomy of the Midbrain |Anatomy of the Pons

Note: Anatomical images of the pons are typically oriented upside-down compared with CT/MRI, except as shown below.

Introduction

• Ischaemic strokes in the pons are commonly lacunar-type infarcts.
• Risk factors include age, hypertension, diabetes, and atherosclerosis.

Aetiology

• Most pontine strokes are unilateral and result from small vessel occlusion of penetrating vessels.
• Basilar artery occlusion affecting the ostia can occasionally lead to bilateral infarction.
• Small vessel strokes share risk factors with other small vessel diseases, including hypertension, diabetes, and age.
• Large vessel basilar infarcts share risk factors with other large vessel strokes, such as atherosclerosis and embolism.
• Swelling near the fourth ventricle may result in obstructive hydrocephalus, sometimes requiring shunting.

Clinical Features

• Contralateral weakness and sensory loss
• Absence of cortical signs or hemianopia
• Ipsilateral facial palsy
• Diplopia or lateral gaze palsy if the VIth nerve is affected
• Potential for coma, locked-in syndrome with preserved upward gaze, pinpoint pupils
• Pyrexia and autonomic dysfunction
• Facial weakness, LMN or UMN, ipsilateral
• Quadriparesis due to corticospinal tract involvement
• Possible waxing and waning of symptoms, resembling capsular warning syndrome
• Sensory symptoms and dysarthria-clumsy hand syndrome (lacunar syndrome)
• Vertigo or dizziness due to cerebellar peduncle involvement

Images

Infarcts typically respect the midline and may extend to the cerebellum.

Investigations

• FBC, U&E, LFTs, Glucose, Lipid profile
• CT/CTA: To assess for acute stroke and vascular integrity as needed.
• MRI: Provides better visualization of infarct location and extent.
• MRA: To assess for vascular stenosis if suspected.

Management

• Reperfusion Therapies: Consider where indicated, as reperfusion of the basilar/penetrating vessels may be beneficial.
• Stroke Unit Admission: For specialized care and monitoring.
• Antiplatelet Therapy: Aspirin 300 mg ± Clopidogrel for initial management.
• Risk Factor Optimization: Blood pressure control for hypertension and glucose management for diabetic patients.
• Statin Therapy: To lower cholesterol and reduce stroke risk.
• Rehabilitation Therapy: PT/OT and SLT as swallow and speech may be affected.