Results of upper cervical palpation test in migraine patients are not explained by pain sensitization

Key points

1. 01UPT subgroups (no pain, local pain, referred pain) showed no statistically significant differences in central sensitization (CSI), allodynia (ASC-12), or pain threshold measures (all p > 0.05)
2. 0283% of migraine patients perceived local or referred neck pain during the UPT, consistent with prior studies
3. 03Neck disability (NDI) was explained 43.6% by CSI and neck pain intensity, suggesting NDI in migraine populations reflects sensitization more than musculoskeletal dysfunction
4. 04CSI was explained 49.4% by allodynia (ASC-12) and NDI, and the UPT did not significantly contribute (p = 0.056)
5. 05The CSI may overestimate central sensitization in migraine patients because roughly one-third of its items describe typical migraine symptoms such as headache, nausea, and light sensitivity

How it was conducted

Design

Cross-sectional observational study with exploratory regression analysis; pre-registered on OSF

Participants

42 adults with episodic migraine (ICHD-3 criteria), at least 2 headache days per month, assessed pain-free and medication-free on the day of testing

UPT subgroups

No pain (n = 7), local pain (n = 17), referred pain (n = 18) based on sustained palpation at C1 and C2 transverse processes

Outcome measures

NDI (neck disability), CSI (central sensitization), ASC-12 (allodynia), mechanical pain threshold (MPT) and pressure pain threshold (PPT) at neck, trigeminal V1, and arm

Statistical approach

Kruskal-Wallis and chi-square for group differences; multinomial logistic regression for UPT subgroup prediction; multilinear regression for NDI and CSI as dependent variables

What they found

• No significant differences across UPT subgroups for CSI (p = 0.167), NDI (p = 0.456), or ASC-12 (p = 0.759)
• No significant differences across UPT subgroups for any MPT or PPT site (all p > 0.05, range p = 0.396 to 0.984)
• Multinomial logistic regression model predicting UPT group was not significant (X2 = 10.540, df = 8, p = 0.229)
• NDI was explained 43.6% by CSI (p < 0.001) and neck pain intensity (p = 0.032): model F = 16.870, p < 0.001, R2 adjusted = 0.436
• CSI was explained 49.4% by ASC-12 (p = 0.006) and NDI (p < 0.001): model F = 14.328, p < 0.001, R2 adjusted = 0.494
• 83% of patients perceived local or referred pain on UPT; 43% perceived referred pain to the head

Limitations

• Very small subgroup sizes (no pain n = 7), limiting statistical power to detect real differences
• Migraine cycle phase was not controlled - sensitization measures may differ between ictal, interictal, and postictal states
• Only C1 and C2 were palpated; mid and lower cervical segments were not assessed, so the source of reported neck disability remains unclear
• No imaging was performed to confirm upper cervical pathology identified by the UPT

Why it matters

For patients

Patients with migraine who experience neck pain during a cervical examination may have a mechanical upper cervical issue rather than simply heightened pain sensitivity, which could mean targeted physiotherapy is appropriate.

For clinicians

The NDI and CSI have limited utility for explaining UPT subgroup findings in migraine; clinicians should not assume a positive UPT is driven by central sensitization alone, and further investigation of C1-C2 musculoskeletal dysfunction is warranted.

For readers

This study challenges two common explanations for neck pain sensitivity in migraine and suggests the UPT captures a distinct, likely structural, cervical construct that needs validation in larger studies.