Abstract
Introduction
Increasing attention is being paid to the role of peripheral factors in the genesis or modulation of headaches. Here we report the case of a patient with hemicrania continua (HC) associated with ipsilateral trochlear pain. Separate treatments with indomethacin and trochlear injection of corticosteroids were absolutely effective in controlling both ocular and head pain.
Case report
A 53-year-old woman, with no relevant medical history, came to our office complaining of chronic headache. The headache had started gradually 3 years before, and had persisted without remission since onset. It had remained strictly unilateral with no side shift. The pain was mostly located in the right periocular region, but normally spread backwards through the right side of the head to the occipital region. The headache was daily and continuous but fluctuating. Upon a background of tightening pain of moderate intensity with a score around 4 out of 10, there were occasional exacerbations of excruciating pain, which recurred two to four times monthly and lasted up to 24 h. The patient had realized that the exacerbations could be triggered by ocular pressure. When the pain was most severe, it was frequently accompanied by nausea, vomiting, photophobia, phonophobia, ipsilateral ptosis and nasal congestion. Treatment with several analgesics (paracetamol, metamizol) and non-steroidal anti-inflammatory drugs (ibuprofen, naproxen, diclofenac, dexketoprofen, pyroxicam, lornoxicam) had been unhelpful. Long-term treatment with antidepressants (amitriptyline, mirtazapine, duloxetine) and anticon vulsants (gabapentin, pregabalin) had also been ineffective.
Physical examination did not disclose any neurological deficit, but compression of the right trochlear area evoked both local tenderness and ipsilateral atrocious sharp pain over the right hemicranium, which resembled the patient's usual bouts of severe headache.
All laboratory tests were normal, including routine blood work-up, erythrocyte sedimentation rate, thyroid function tests, antinuclear antibodies, and rheumatoid factor. Computed tomography and magnetic resonance imaging of the orbit and brain also failed to show any abnormality.
A therapeutic trial with indomethacin 50 mg t.i.d. provided a complete response. However, indomethacin had to be stopped after 2 weeks due to an allergic cutaneous reaction. Soon after withdrawal of indomethacin, the headache recurred with the prior features. Once the pain had been continuous for 1 week, 4 mg of triamcinolone acetonide was injected with a 30-G needle in the symptomatic trochlear region. Both the local tenderness and the headache completely disappeared within 48 h, and did not reappear during a follow-up period of 3 months.
Discussion
In 2004 Yangüela et al. described primary trochlear headache (PTH), a disorder with periorbital pain stemming from the trochlear area in the absence of any local or systemic disease (1). Pain of PTH is typically increased by mechanical factors, such as palpation of the upper-inner angle of the orbit or vertical eye movements. Otherwise, the pain is relieved by injecting local anaesthetics or corticosteroids on the involved trochlea.
Since PTH was described, trochlear pain—or referred pain on examination of the trochlea—has been frequently found in patients with other primary headaches, especially migraine (1–4) and tension-type headache (1,5). Moreover, better control of concurrent headaches has been achieved after injection of corticosteroids on the sore trochlea (1,6). Therefore, nociceptive inputs from the trochlear region may trigger or modulate other headache disorders, and decreasing the possible wind-up induced from this nociceptive afferent stimulation may be effective in controlling headache (7). Other interventions on peripheral inputs (e.g. peripheral nerve blocks) also appear to be useful in the treatment of different primary headaches (8).
Our patient fulfilled the International Headache Society diagnostic criteria for HC (9). As is currently required for HC diagnosis, her headache was absolutely responsive to indomethacin. She also had a trigger point in the ipsilateral trochlear region, and local injection of corticosteroids eliminated her pain when indomethacin had to be discontinued. This is the first time that a benefit of trochlear steroid injection has been reported in HC. On the other hand, it is the first time that a benefit of indomethacin has been reported in trochlear pain. Pego-Reigosa et al. also found a therapeutic effect of trochlear injection of corticosteroids in another indomethacin-responsive headache—chronic paroxysmal hemicrania—associated with ipsilateral PTH (10). In their patient indomethacin had abolished the symptoms of chronic paroxysmal hemicrania, but had not controlled the coexisting trochlear pain.
In conclusion, trochlear injection of corticosteroids may be effective in HC and other types of headache in which nociceptive inputs from the trochlear region could contribute to the genesis or maintenance of the pain. We believe that the trochlea should be examined in every patient complaining of orbital pain or headache.