Can high-grade stenosis of the inferior cerebellar artery cause vertigo symptoms?

High-Grade Inferior Cerebellar Artery Stenosis and Vertigo

Yes, high-grade stenosis of the inferior cerebellar arteries (PICA or AICA) can absolutely cause vertigo symptoms and represents a serious vascular emergency requiring urgent evaluation. 1, 2

Mechanism and Clinical Significance

Vertigo is a recognized and well-documented symptom of vertebrobasilar insufficiency, including stenosis of the inferior cerebellar arteries. 1 The mechanism involves:

• Compromised vertebrobasilar perfusion leading to ischemia of the cerebellum, brainstem, and inner ear structures 1
• Atheroembolism from stenotic lesions causing brainstem or cerebellar infarction 1
• Transient ischemia to the inner ear or vestibular nerve, particularly with AICA stenosis which supplies the internal auditory artery 3, 4

The posterior inferior cerebellar artery (PICA) is a branch of the V4 segment of the vertebral artery, and the anterior inferior cerebellar artery (AICA) arises from the basilar artery. 1 Vertebral artery atherosclerosis accounts for approximately 20% of posterior circulation strokes, and vertebrobasilar arterial stenosis is associated with multiple ischemic episodes and higher risk of early recurrent stroke. 1, 2

Critical Clinical Presentations

Symptoms associated with vertebral artery and inferior cerebellar artery disease include dizziness, vertigo, diplopia, perioral numbness, blurred vision, tinnitus, ataxia, bilateral sensory deficits, and syncope. 1

PICA Territory Stenosis/Infarction:

• Isolated vertigo can be the presenting symptom in approximately 11% of patients with isolated cerebellar infarction, most commonly in the medial branch of PICA territory 4
• May present with vertigo alone for months before progressing to complete infarction 3
• Can mimic acute peripheral vestibulopathy 4

AICA Territory Stenosis/Infarction:

• Combination of vertigo with hearing loss and tinnitus is characteristic 3, 4, 5
• Affects both peripheral (inner ear) and central (brainstem/cerebellar) structures 3
• Acute hearing loss with vertigo can be the initial symptom of impending posterior circulation stroke 4, 5

Urgent Management Approach

A patient with high-grade stenosis in the inferior cerebellar artery territory presenting with intermittent dizziness should be immediately referred to the emergency department for urgent evaluation due to the high risk of stroke. 2 The intermittent symptoms may represent transient ischemic attacks (TIAs), which carry up to a 13% stroke risk in the first 90 days. 2

Immediate Diagnostic Workup:

• Complete neurovascular assessment with detailed neurological examination focusing on speech, gait, coordination, eye movements, and truncal ataxia (commonly missed on bedside examination) 1
• MRI head without IV contrast for detection of posterior fossa infarcts 1
• CTA or contrast-enhanced MRA for vascular imaging, as these have higher sensitivity (94%) and specificity (95%) than ultrasonography (70% sensitivity) for vertebral artery stenosis 1
• Catheter-based angiography may be required for definitive assessment, particularly for vertebral artery origins and planning potential interventions 1, 2
• Cardiac evaluation to rule out cardiogenic embolism sources 1, 2

Treatment Priorities:

• Immediate initiation of antithrombotic therapy is warranted 2
• Medical management includes antiplatelet therapy, statins, and aggressive risk factor modification 1, 2
• Revascularization options (surgical or endovascular) should be considered based on severity and symptomatology, coordinated with neurology, neurosurgery, and interventional radiology 1, 2

Critical Pitfalls to Avoid

The most dangerous pitfall is dismissing isolated vertigo or dizziness as benign peripheral vestibulopathy when high-grade vascular stenosis is present. 1, 2, 4 Specific concerns include:

• Delaying evaluation of intermittent dizziness in the setting of known high-grade vascular stenosis can lead to preventable strokes 2
• Missing truncal ataxia during bedside examination in patients with cerebellar stroke 1
• Failing to recognize that dizziness may be the only presenting symptom of posterior circulation ischemia 2
• Assuming normal initial CT excludes cerebellar infarction, as initial CT can be normal in up to 25% of patients with cerebellar stroke 1
• Not obtaining vascular imaging when MRI shows no acute infarct, as a negative MRI does not exclude chronic ischemia without completed infarction 1

Distinguishing Features

Head impulse testing can differentiate acute isolated vertigo from PICA territory cerebellar infarction versus benign peripheral vestibulopathy. 4 Additional red flags suggesting central (vascular) rather than peripheral causes include:

• Risk factors for cerebrovascular disease 3, 6
• Associated neurological symptoms (facial numbness, hemiataxia, hearing loss) 3, 4
• Inability to stand or walk (severe truncal ataxia) 1
• Altered level of consciousness indicating tissue swelling 1

After initial stabilization, these patients require close neurovascular follow-up and implementation of secondary stroke prevention strategies. 2