Can chronic microangiopathic changes on a CT (Computed Tomography) Head exam cause dizziness?

Can Chronic Microangiopathic Changes Cause Dizziness?

Yes, chronic microangiopathic changes (white matter hypodensities) can cause dizziness, particularly manifesting as chronic disequilibrium rather than acute vertigo, though the CT findings in this case show no acute abnormality requiring immediate intervention. 1, 2

Understanding the Clinical Context

The CT report describes bilateral white matter hypodensities consistent with chronic microangiopathic changes (also termed cerebral small vessel disease). These findings represent chronic microvascular ischemic changes that can contribute to neurological symptoms including dizziness and gait instability. 1

Mechanism of Dizziness in Microangiopathy

• Cerebral microangiopathy causes diffuse brain tissue changes (encephalopathy) that manifest clinically as cognitive impairment and disorders of gait, which patients often describe as dizziness or disequilibrium. 1
• White matter lesions from microangiopathy can impair vestibular system function and balance control, leading to a somatosensory-dependent pattern of postural instability. 2
• The dizziness associated with microangiopathy typically presents as chronic disequilibrium (persistent unsteadiness) rather than acute vertigo (spinning sensation). 3

Critical Distinction: What This CT Does NOT Show

The CT shows no acute intracranial abnormality - meaning no acute stroke, hemorrhage, or mass effect that would require emergency intervention. 4

Important Limitations of CT for Dizziness Evaluation

• CT head has a very low diagnostic yield (<1%) for isolated dizziness and sensitivity of only 20-40% for detecting causative pathology. 4, 5
• CT is particularly poor at detecting posterior circulation infarcts, which are the most common central cause of acute dizziness. 4
• MRI with diffusion-weighted imaging has significantly higher diagnostic yield (4% in isolated dizziness, up to 16% when changing diagnosis) compared to CT. 4, 6

Clinical Approach to This Patient

Categorize the Dizziness Pattern

The history mentions "worsening headaches, dizziness, falls" - this suggests Chronic Vestibular Syndrome (persistent disequilibrium) rather than acute vertigo. 5, 3

Red Flags Requiring Urgent MRI

• New severe headache accompanying dizziness mandates immediate imaging and neurologic consultation. 3
• Inability to stand or walk is a red flag requiring urgent evaluation. 3
• Focal neurological deficits would necessitate MRI to exclude posterior circulation stroke. 4, 3

When Chronic Microangiopathy IS the Cause

• Patients with chronic microangiopathy and dizziness typically demonstrate gait disorders and postural instability rather than true vertigo. 1, 2
• The combination of white matter changes on imaging with clinical manifestations of cognitive impairment and gait disturbance establishes the diagnosis of microangioencephalopathy. 1
• Comprehensive vestibular testing can quantify the level of vestibular system involvement and guide rehabilitation strategies. 2

Management Implications

This Patient Likely Needs

• MRI brain without contrast if there is concern for acute posterior circulation stroke (given the falls and worsening symptoms), as CT is inadequate for excluding this diagnosis. 4, 5, 6
• Vestibular rehabilitation may be beneficial for chronic disequilibrium related to microangiopathy. 2
• Vascular risk factor modification (blood pressure control, antiplatelet therapy if appropriate) to prevent progression of microangiopathy. 1

Common Pitfall to Avoid

Do not assume the normal CT excludes a central cause of dizziness. CT misses many posterior circulation infarcts, and 75-80% of patients with acute vestibular syndrome from posterior circulation infarct have no focal neurologic deficits on examination. 3

Bottom Line

The chronic microangiopathic changes seen on this CT can contribute to chronic dizziness and falls through mechanisms of gait impairment and postural instability. 1, 2 However, the "worsening" nature of symptoms and falls warrant consideration of MRI to exclude an acute posterior circulation stroke that CT would miss, particularly given the patient's underlying cerebrovascular disease. 4, 6 The chronic white matter changes represent a substrate for ongoing neurological symptoms but do not explain acute worsening without additional evaluation.