Pressure pain thresholds over the cranio-cervical region in headache: a systematic review and meta-analysis

DOI: https://doi.org/10.1186/s10194- 018- 0833- 7

Abstract-Summary A systematic review was conducted to assess the current scientific literature describ- ing pressure pain threshold (PPT) values over the cranio-cervical region in patients with migraine, tension-type headache (TTH), and cervicogenic headache (CeH).

The search strategy included the following keywords: migraine, TTH, CeH, PPT

and algometry.

Mean PPT values of several sites measured in the cranio-cervical region in patients with migraine, chronic TTH and CeH scored lower values compared to controls.

The trapezius muscle (midpoint between vertebrae C7 and acromion) was the most frequently targeted site and showed significantly lower PPT values in adults with migraine (pooled standardized mean difference kPa: 1.26 [95%CI −1.71, −0.81]) and chronic TTH (pooled standardized mean difference kPa: −2.00 [95%CI −2.93, −1.08]).

Most studies found no association between PPT values and headache character-

istics such as frequency, duration or intensity.

3.3 Clinical Diagnosis

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Further standardization of PPT measurement in the cranio-cervical region is

recommended.

Extended: Most studies found no significant association of headache characteris- tics (frequency, intensity, duration) with PPT values within the different types of headache.

Review PPT represent the sensitivity of tissues and depending on the site of measurement (cervico-cephalic and/or extra-cervico-cephalic region) where these PPT are decreased, they are supposed to reflect signs of sensitization of the trigemino- cervical nucleus caudalis [261–263].

People with headache can be expected to have lower PPT values in the cranio-

cervical region.

To date, no aggregated evidence on the association between PPT values in the

cranio-cervical region and headache is available.

Physical- and manual therapy interventions are predominantly directed to the

cranio-cervical region in order to reduce headaches [264]

Providing clinicians who administer such interventions with reference PPT val- ues in the cranio-cervical region may assist them in their evaluation of PPT values. The question of this review is whether PPT values in the cranio-cervical region in participants with migraine, TTH and CeH are decreased compared to healthy controls.

Methods This limitation of the search period was to ensure the inclusion of studies that were published after the publication of the updated and more detailed classification of headaches, especially TTH (ICHD II, 2004).

Two reviewers (RC, WDH) independently screened the titles and abstracts of the

citations generated by the literature search.

The following inclusion criteria were applied to decide if papers would be included for further evaluation: (a) headaches were classified as migraine, TTH or CeH, (b) pain threshold measurements (algometry) were applied in the cranio- cervical region, (c) scores on PPT were available, (d) research involved humans, (e) were case-control studies, and (f) research was published after 2004.

These five selected criteria items were, independently, scored by two reviewers (RC, WD) as either “positive”, “negative” or “unclear”, in case an item was inade- quately reported upon.

In case pooling of data was considered we assessed the following sources: clas-

sification of headache, age, site of measurement, and measurement units.

Results Mean PPT scores of a combination of measurements on the splenius muscle, trape- zius muscle, temporalis muscle, and index finger in migraine were described in two studies by Engstrom and others in which one study reported significant lower values between not sleep-related migraine versus controls (kPa: 519, sd 125 vs kPa: 661, sd 249 p = 0.05, 16,18).

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3 Diagnosis

Three studies reported PPT values in the cranio-cervical region in participants with CeH. Zito and others found no between-group differences in PPT scores at the C2–3 zygapophyseal joint, but significantly lower PPTs in the area over the trans- verse process of C4 in comparison to the control group (P 0.05) [265].

Participants with chronic TTH show significant lower PPT values at three differ-

ent sites in the neck region (i. the suboccipital muscle insertions, ii.

Discussion It is noteworthy that in four out of five studies the suboccipital region reported sig- nificantly lower PPT in chronic TTH and migraine.

This limitation can be considered as a weakness of this study because this paper covers not all available evidence on PPT measurement over the cranio- cervical region. The validity of the reported results on PPT values in the selected studies there-

fore depends partly on the reliability of measurement.

Although the performance of the PPT measurement was comparable across the

studies there was a great variety of sites measured in the cranio-cervical region.

Some studies reported sum scores, i.e. average mean scores of the PPT of mul- tiple sites in the cranio-cervical region or cranio-cervical sites in combination with extra-cephalic sites.

All studies show lower, but not in all studies significantly lower, PPT values in

the cranio-cervical region in patients with headache versus controls.

Conclusion We conclude that the PPT values of the trapezius muscle are significantly lower in migraine and chronic TTH compared to controls.

No significant associations were reported between PPT values in the cranio- cervical sites and headache characteristics such as frequency, duration or intensity. The increased sensitivity of cranio-cervical sites supports the neurophysiological

model of sensitization in migraine and chronic TTH.

Acknowledgement A machine generated summary based on the work of Castien, René F.; van der Wouden, Johannes C.; De Hertogh, Willem. 2018  in The Journal of Headache and Pain.

The validation of the Hungarian version of the ID-migraine questionnaire