What is the recommended imaging for a patient experiencing dizziness with neck flexion?

Imaging for Dizziness with Neck Flexion

In patients with dizziness provoked by neck flexion, imaging is generally not indicated unless "red flag" symptoms are present, and clinical assessment should focus on distinguishing between benign cervicogenic dizziness and serious vascular or neurological pathology.

Clinical Assessment Takes Priority Over Imaging

The key to managing dizziness with neck flexion is recognizing that most cases do not require imaging and can be diagnosed clinically 1. The American College of Radiology emphasizes that imaging has very low diagnostic yield in isolated dizziness, with CT detecting causative pathology in less than 1% of cases 1, 2.

Critical "Red Flag" Symptoms Requiring Urgent Imaging

You must immediately obtain imaging if any of these features are present:

• Focal neurological deficits (even though 75-80% of posterior circulation strokes present without focal deficits) 3
• Sudden severe headache accompanying dizziness 3
• Inability to stand or walk 3
• Sudden hearing loss 3
• Downbeating nystagmus or other central nystagmus patterns 3
• Abnormal HINTS examination (Head Impulse, Nystagmus, Test of Skew) suggesting central cause 3

Recommended Imaging Algorithm

When No Red Flags Present

No imaging is indicated 1, 3. The diagnosis is clinical, focusing on:

• Timing and triggers of dizziness (more valuable than patient's subjective description) 3
• Positional testing (Dix-Hallpike maneuver for BPPV) 3
• Medication review (a leading reversible cause of chronic dizziness) 3
• Assessment for cervical musculoskeletal disorders 4

When Red Flags Are Present

MRI brain without contrast is the first-line imaging modality 1, 3, 2. MRI has superior sensitivity (4% diagnostic yield vs <1% for CT) and is essential for detecting posterior circulation infarcts, which CT frequently misses 1, 2.

CT head without contrast may be appropriate only as an initial emergency study when immediate stroke evaluation is needed and MRI is not immediately available 2. However, recognize that CT has only 20-40% sensitivity for detecting causative pathology in dizziness 1.

Special Consideration: Vascular Imaging

CTA head and neck should NOT be routinely ordered for isolated dizziness with neck flexion 1. CTA has only 14% sensitivity and 3% diagnostic yield in isolated dizziness, providing no additional information beyond non-contrast CT 3.

Exception: CTA is appropriate if there is pulsatile tinnitus accompanying dizziness, as this suggests vascular pathology such as arterial dissection 3. Vertebral artery dissection can present with neck pain and dizziness following minor trauma, though it remains frequently missed 5.

Cervical Spine Imaging: Generally Not Indicated

Do not routinely image the cervical spine for dizziness with neck flexion 1. The evidence shows:

• MRI cervical spine is not useful as first-line imaging in the absence of red flags 1
• Structural abnormalities of the cervical spine (cord compression, facet degeneration, vertebral artery compression) are equally common in dizzy and non-dizzy elderly patients 6
• Flexion-extension radiographs are not supported by literature as first-line imaging for this scenario 1

Exception: MRI cervical spine without contrast may be considered if there are progressive neurological symptoms suggesting cervical myelopathy or if there is concern for spinal cord compression with positional changes 7, 8. However, this is distinct from isolated dizziness and represents a different clinical syndrome.

Critical Pitfalls to Avoid

• Do not rely on normal neurological exam to exclude stroke – most posterior circulation strokes present without focal deficits 3
• Do not use CT instead of MRI when stroke is suspected – CT misses many posterior circulation infarcts 3
• Do not order routine imaging for typical BPPV – this delays appropriate treatment with canalith repositioning procedures 3
• Do not assume cervical spine pathology causes dizziness – structural abnormalities are common in asymptomatic individuals 6
• Do not order CTA routinely – it has extremely low yield (3%) in isolated dizziness 3

Management Without Imaging

For most patients with dizziness provoked by neck flexion and no red flags:

• Perform Dix-Hallpike maneuver to diagnose BPPV (most common cause of positional dizziness) 3
• Treat BPPV with Epley maneuver (80-98% success rate) if positive 3
• Consider cervicogenic dizziness and treat with cervical musculoskeletal therapy and sensorimotor control exercises 4
• Review medications for vestibulotoxic agents 3
• Reassess within one month if symptoms persist 3