Individuals with primary headache, such as chronic migraine or tension-type headaches, often complain of neck pain, while those with neck pain may complain of headache. Even though neck pain is commonly linked to primary headaches, no objective biomarkers exist for the myofascial involvement in primary headaches.
Nico Sollmann, MD, PhD, and colleagues investigated the involvement of the trapezius muscle in both types of pain using quantitative magnetic resonance imaging. They explored the association between muscle T2 values and headache frequency and neck pain. The team evaluated 16 individuals with tension-type headache, 12 with mixed-type plus migraine, and 22 healthy non-headache controls. They found associations between the muscle T2 values and the presence of neck pain as well as the number of days of headache monthly. Their work was published in the Journal of Headache and Pain.
MedCentral spoke to lead researcher Dr. Sollmann, a resident at University Hospital Ulm and University Hospital Rechts der Isar in Munich, Germany, to dig further into his team’s findings and how to evaluate patients with both neck pain and primary headache.
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How might your research affect the clinical assessment of patients presenting with headache?
Dr. Sollmann: If patients with primary headaches suffer from pain at the neck and shoulder area at least from time to time, the systematic assessment of the neck area may become part of the diagnostic workup and could also provide therapeutic opportunities.
In your experience, how often is neck pain associated with primary headaches?
Dr. Sollmann: Neck pain is indeed frequently associated with primary headaches. Although the centrally driven pathophysiological mechanisms in primary headache disorders have been in the focus for a long time, more and more attention is paid to the role of peripheral myofascial involvement. In this regard, there might be relevant connections between the trigeminal nerve and the pericranial musculature, as well as between the trigeminal system and nociception stemming from the neck muscles (including the upper trapezius muscles).
The nociceptive sensation at the neck is mostly conveyed via the Aδ and C fibers running within the upper cervical nerves to the trigemino-cervical nucleus and is further processed with trigeminal afferent inputs, representing the so-called trigemino-cervical complex.
Clinically, pain arising from the neck muscles can be perceived as migraine-like headache and/or trigger a headache attack, in addition to local pain at the neck that has shown high prevalence among patients with migraine. As such, neck pain has been identified as an even more frequent accompaniment of migraine attacks than nausea [a prominent cardinal symptom accompanying symptom of migraine].
How is the trapezius muscle potentially involved in primary headache disorders?
Dr. Sollmann: The trapezius muscles are among the largest skeletal muscles in humans and are easily accessible for manual or other examinations, given their superficial location. Investigations were successful in provoking headache attacks by simple manual palpations of certain points within those muscles. The trapezius muscles are innervated by anterior rami of cervical spinal nerves, thus connect to the concept of the trigemino-cervical complex.
Given this innervation profile and potential role within the trigemino-cervical complex, the trapezius muscle may be a structure of particular interest to investigate the myofascial involvement in primary headaches.
Should physicians consider imaging to aid in the evaluation of muscle T2 values and headache frequency and neck pain?
Dr. Sollmann: Quantitative MRI using T2 mapping may allow for [detection of] altered muscle T2 values in the trapezius muscles, and elevated muscle T2 may be interpreted as subtle inflammatory changes. To date, no standardized objective imaging-based biomarkers from musculature are available for diagnostics or severity grading in primary headaches.
Of note, MRI is the only non-invasive modality that could identify, characterize, and – even in the case of only subtle alterations – quantify such inflammatory changes of muscles with high resolution. Hence, imaging by MRI could be a viable add-on option for phenotyping of patients with headaches, which nowadays primarily relies on clinical and rather subjective parameters that are reported by the patients.
Data suggesting close associations between findings from T2 mapping derived from MRI (eg, elevated muscle T2) and headache characteristics (eg, headache frequency) can set imaging findings in clinical context, thus the meaningfulness of findings from MRI for evaluating the role of the musculature in primary headaches could be determined.
Is this MRI technology widely available?
Dr. Sollmann: The approach of quantitative MRI to study the neck musculature in patients with primary headaches is currently under development and primarily available for research purposes [related to relatively high costs and limited availability].
If increased T2 of the trapezius muscle is found, what should a physician consider?
Dr. Sollmann: Increased T2 values derived from the trapezius muscles may point at subtle inflammatory changes and could potentially serve as evidence for the involvement of those muscles in the pathophysiology of primary headache disorders. There are treatment approaches becoming available that specifically target the musculature non-invasively, such as peripheral magnetic stimulation. Hence, in the future, a loop between imaging and treating the muscular component in primary headaches may be developed.
