What diagnostic work‑up (laboratory tests and imaging) should be ordered for a 20‑year‑old with a several‑month history of dizziness and visual changes?

MRI Brain Without and With Contrast is the Recommended Initial Imaging Study

For a 20-year-old with months of dizziness and vision changes, order MRI brain (head) without and with IV contrast as the primary imaging study, along with targeted laboratory testing to exclude systemic causes.

Diagnostic Approach

Imaging Strategy

The chronic, progressive nature of symptoms in a young patient raises concern for central pathology that requires high-resolution soft tissue imaging. MRI brain with and without contrast is superior to CT for detecting masses, demyelinating disease (such as multiple sclerosis), inflammatory processes, and vascular lesions—all of which can present with this symptom constellation 1, 2.

Key considerations for imaging selection:

• CT head has poor diagnostic yield (only 1.6% for emergent findings in dizzy patients) and inferior soft tissue resolution 3
• MRI changes the diagnosis in up to 16% of cases when CT is negative, with acute findings in 8% 3
• The combination of dizziness AND vision changes suggests potential involvement of multiple neural pathways, making comprehensive brain imaging essential 2

Specific MRI Protocols

Based on the symptom pattern, consider:

1. MRI brain without and with contrast (primary study) 1, 2

   • Detects demyelinating disease, masses, inflammatory processes
   • Essential for characterizing lesions affecting visual and vestibular pathways

2. Add MRI orbits without and with contrast if vision loss is prominent 2

   • Superior for optic nerve pathology
   • Differentiates optic neuritis, compressive lesions, and infiltrative disease

3. Consider MRI internal auditory canals if auditory symptoms coexist 1

   • Evaluates for vestibular schwannoma or other skull base pathology

Laboratory Workup

While imaging is prioritized, obtain:

• Complete blood count (infection, anemia)
• Comprehensive metabolic panel (electrolyte disturbances, renal/hepatic function)
• Thyroid function tests (thyroid disease can cause both symptoms)
• Vitamin B12 level (subacute combined degeneration)
• ESR/CRP (inflammatory/autoimmune conditions) 4
• Consider autoimmune panel if clinical suspicion exists (ANA, anti-dsDNA, ANCA) 4

Clinical Context Matters

The months-long duration distinguishes this from acute vestibular syndromes (vestibular neuritis, BPPV) which typically resolve or improve within weeks 1. This chronicity combined with vision changes creates red flags for:

• Demyelinating disease (multiple sclerosis)—most common in this age group
• Posterior fossa tumors (cerebellar or brainstem)
• Autoimmune/inflammatory conditions 4
• Chronic cerebral ischemia (less likely at age 20 unless risk factors present)

Common Pitfalls to Avoid

1. Don't order CT head first—it will likely be negative and delay definitive diagnosis while exposing the patient to radiation 3

2. Don't assume peripheral vestibular disease—isolated peripheral causes (BPPV, vestibular neuritis, Ménière's) don't typically cause vision changes and don't persist for months without improvement 1, 5

3. Don't skip contrast administration—contrast is essential for detecting inflammatory, infectious, and demyelinating processes as well as characterizing masses 1, 2

4. Don't forget ophthalmology referral—vision changes require formal visual field testing and fundoscopic examination to localize pathology along the visual pathway 2

The combination of chronic dizziness with vision changes in a young adult demands aggressive workup because treatable conditions (demyelinating disease, inflammatory disorders) require early intervention to prevent permanent disability and preserve quality of life 4.