Imaging in the dizzy patient with neck pain is a discipline of restraint. The cervical spine is degenerate by middle age in most adults, and an MRI that shows osteophytes, disc bulges, and facet arthropathy is showing background noise — not the cause of the symptom. This module covers the two scenarios where imaging genuinely changes management, the one rare-but-serious vascular diagnosis worth catching (rotational vertebral artery syndrome), and the larger group of patients for whom the right answer is no imaging at all.
The short version
Most patients with cervicogenic dizziness do not need imaging. That seems counterintuitive — imaging feels like it should help — but the cervical spine wears out predictably with age, and a report saying "degenerative changes" in a 55-year-old simply confirms that the patient is 55. It does not link the neck to the symptom.
Imaging is reserved for two situations:
Red flags suggesting central or sinister pathology — new focal neurological deficits, acute persistent symptoms, sudden hearing loss, or trauma. These get an MRI of the brain and inner ear pathways.
Rotation-triggered brainstem symptoms — specifically vertigo with presyncope or drop attacks that only appear when the head is turned to a particular side. These are screened with a dynamic Doppler of the vertebral arteries and confirmed, if positive, with vascular imaging.
A typical cervicogenic dizziness patient — chronic neck pain, dizziness reproduced by neck position, no red flags, a clean vestibular workup — needs no imaging at all.
Figure 6.2 — Imaging decision tree. The default answer in cervicogenic dizziness is no imaging: when peripheral and central vestibular pathology has been excluded clinically (Module 5) and there are no red flags, neither cervical-spine radiographs nor cervical MRI typically alter management. Imaging is reserved for two scenarios — red-flag features that suggest central or sinister pathology (MRI brain and internal auditory canals) and rotation-triggered brainstem signs that suggest RVAS (vascular imaging ladder).
One sentence to remember. The cervical spine MRI does not diagnose cervicogenic dizziness; it only rules out structural pathology you specifically suspected for other reasons.
Why default imaging is low yield
A retrospective Spanish series studied imaging utilisation in patients presenting with vertigo or dizziness: 57% had cervical radiographs ordered, and 74% of those showed degenerative changes — osteophytes in nearly half, abnormal lordosis in a third. The authors concluded that despite these findings, the radiographs did not aid the diagnosis of cervical vertigo.34 Two distinct observations underlie the disconnect:
Degeneration is the demographic baseline. By age 60, cervical osteophytes, disc desiccation, and facet arthropathy are visible in the great majority of asymptomatic adults. Their presence in a symptomatic patient is not informative.
Cervicogenic dizziness has no characteristic structural lesion. Unlike radiculopathy, where a disc-foraminal correlation can be made, the proprioceptive disturbance that underlies cervical dizziness arises from muscle spindle and joint-capsule receptors that imaging cannot directly see.
ACR Appropriateness Criteria reflect this: for adults with dizziness and a normal neurological examination consistent with peripheral vertigo, neither cervical-spine MRI nor MRA neck is rated "usually appropriate" as initial imaging.36
When imaging is indicated
Figure 6.2 — Imaging decision tree. The default answer in cervicogenic dizziness is no imaging: when peripheral and central vestibular pathology has been excluded clinically (Module 5) and there are no red flags, neither cervical-spine radiographs nor cervical MRI typically alter management. Imaging is reserved for two scenarios — red-flag features that suggest central or sinister pathology (MRI brain and internal auditory canals) and rotation-triggered brainstem signs that suggest RVAS (vascular imaging ladder).
Red flags — image the brain
MRI brain with internal auditory canals is the first-line study when any of the following are present:
Focal neurological deficit — diplopia, dysarthria, hemiparesis, hemisensory loss, ataxia, or a crossed sensory pattern.
Acute persistent vertigo with normal head impulse test (the HINTS battery from Module 5) — strongly suggestive of posterior-circulation stroke.32
Asymmetric sensorineural hearing loss — to exclude vestibular schwannoma.
Recent significant trauma — to evaluate cervical fracture, ligamentous injury, or traumatic dissection.
Age over 60 with new vascular risk factors and acute onset — to evaluate posterior-circulation infarct.
RVAS suspected — the vascular ladder
Rotational vertebral artery syndrome (Module 3, mechanism 3) is rare but consequential: it is the one cause of position-evoked dizziness on this differential that can cause a brainstem infarct.24 The history is specific — symptoms triggered reproducibly by sustained head rotation to one direction, with brainstem features rather than purely proprioceptive ones — and a positive history justifies a structured vascular workup.
Rotational Vertebral Artery Simulator
Drag to rotate the head 0–90°. The V3 segment is fixed at the dura but its exit from the C2 transverse foramen rotates with C2 — producing a kink. The Doppler waveform shows the haemodynamic consequence: end-diastolic velocity drops first, then peak systolic on more severe compression.
Doppler · V3 segmentNormal triphasic flow
PSV45 cm/s
EDV8.0 cm/s
PatternCompensated
Pattern
End-diastolic velocity falls to zero on extreme rotation; peak systolic preserved. Patient typically asymptomatic — collateral circulation compensates.
Figure 6.1 — Dynamic vertebral artery Doppler. In suspected RVAS, the screening test is dynamic transcranial or cervical duplex Doppler: peak systolic velocity (PSV) and end-diastolic velocity (EDV) are measured in the V3 segment with the head in neutral and again at increasing rotation. Loss of end-diastolic velocity on rotation, with preserved PSV at the same angle, is the early haemodynamic signature; collapse of both PSV and EDV marks the symptomatic threshold. Dynamic CT or MR angiography confirms the level and structural cause.
The ladder, from least invasive to gold standard:
Dynamic transcranial or cervical duplex Doppler — the screening test. Peak systolic and end-diastolic velocities are measured in the V3 segment with the head in neutral and again at progressive rotation. Loss of end-diastolic flow on rotation, with the contralateral side preserved, is the early haemodynamic signature; collapse of both PSV and EDV marks the symptomatic threshold.35
Dynamic CT or MR angiography — acquisitions in neutral and in symptom-provoking rotation. Demonstrates the structural cause (osteophyte, fibrous band, atlantoaxial subluxation) and localises the level.33 CTA is faster and shows bone better; MRA avoids radiation and shows soft-tissue compression.
Dynamic digital subtraction angiography (DSA) — the diagnostic gold standard, capturing the moment of occlusion in real time. Reserved for confirmation when surgical decompression is being planned.35
Cervical spine imaging — when, exactly?
Cervical-spine MRI is justified in the dizzy patient with neck pain only when one of the following is also present:
Cervical radiculopathy — radicular pain, weakness, or sensory loss in a dermatomal distribution.
Cervical myelopathy — gait dysfunction, hand clumsiness, hyperreflexia, Hoffman's or Babinski signs.
Pre-operative planning, where surgical decompression is being considered for a separate indication.
A cervical MRI ordered solely on the basis of neck pain plus dizziness, in the absence of these features, is unlikely to alter management.
Clinical pitfalls and pearls
The dominant vertebral artery matters
In most individuals one vertebral artery is dominant — typically the left, often substantially larger than the right. Rotational compromise of the non-dominant artery rarely produces symptoms because the dominant side and the basilar collaterals maintain perfusion. Compromise of the dominant artery, however, can be symptomatic even at modest rotation angles. When you suspect RVAS, the Doppler must specifically examine the dominant V3.35 A "normal" non-dominant Doppler does not rule out the syndrome.
Dynamic studies require provocation
A static CTA or MRA in a patient with neutral head position will almost always be reported as normal in RVAS — the whole point is that the compromise is dynamic. The imaging request must specify dynamic acquisition with two head positions (neutral and the patient's symptom-provoking rotation), and the patient must be coached to hold the provocative position long enough for image acquisition. Without this, the imaging report will reassure rather than diagnose.33
HINTS overrides imaging in the acute setting
A patient with acute persistent spontaneous vertigo gets a HINTS examination first, not an MRI first. A normal head impulse test in this context is paradoxically the strongest predictor of a central lesion — and early MRI (within 48 hours) can miss posterior-circulation infarcts because diffusion-weighted imaging false-negative rates are high in the first 24 hours of ischaemic events involving the brainstem and cerebellum.32 HINTS-positive patients warrant admission and serial imaging, not a single negative MRI reading as reassurance.
The vestibular schwannoma trap
A 55-year-old patient with chronic neck pain, intermittent imbalance, and unilateral tinnitus is far more likely to have a vestibular schwannoma than cervicogenic dizziness. Any asymmetric audiovestibular feature in a patient otherwise labelled cervicogenic should trigger an MRI brain with internal auditory canal protocol, contrast-enhanced. This catch is inexpensive and consequential.
Cervical spine reports — interpret with restraint
When a cervical-spine MRI has been done for other reasons (often for the neck pain itself), the report will describe degenerative findings. Distinguish between:
Background degeneration — multilevel disc desiccation, facet arthropathy, osteophytes without nerve root or cord compromise. Not a finding that connects to the dizziness.
Compressive pathology — foraminal stenosis with a corresponding clinical radiculopathy, cord signal change, or canal stenosis with a corresponding myelopathy. Manage on its own terms, but do not assume it is the cause of the dizziness without an independent argument.
Specific structural risk factors for RVAS — atlantoaxial subluxation, osteophyte projecting into a transverse foramen, congenital C1–C2 anomalies. These are the imaging findings that do justify proceeding to dynamic vascular imaging.
What gets imaged in the cervicogenic patient who deteriorates
A previously stable cervicogenic patient who returns with new neurological features, escalating symptoms, or symptoms now provoked at smaller rotation angles deserves re-evaluation rather than reassurance. The differential at that point should include developing RVAS, evolving vertebrobasilar atherosclerosis, progression of a missed schwannoma, and new central pathology. The imaging escalation pathway is the same as the initial workup — HINTS first if acute, MRI brain & IAC plus vascular imaging if features warrant.
The clinical synthesis. The cervicogenic diagnosis is supported, not made, by imaging — and most of the time, imaging supports it best by being normal. Save imaging for the two scenarios that actually carry consequence — red flags and rotation-triggered brainstem features — and accept that the typical cervicogenic patient walks out without a scan.