Primary trochlear headache: a new cephalgia generated and modulated on the trochlear region

Background: The authors have observed a group of patients complaining of periorbital pain, emanating from the trochlear area, in absence of trochleitis or other orbital or systemic disease. All were previously diagnosed and treated as different types of headaches, but pain was not controlled until local treatment on the sore trochlea was performed. The authors have investigated the role of the trochlear area in causing and modulating headache.Methods: Observational case series. Trochlear pain was defined as pain on this area, exacerbated upon examination and looking in supraduction. Pain was studied after trochlear injections of lidocaine, corticosteroids, and placebo. Secondary orbital pain was ruled out.Results: Seventeen women and one man were evaluated (mean age: 44 years). All presented unilateral pain in the trochlear area (60% reported more extended headache), for more than 1 year in 70%. Neither ocular autonomic signs nor motility restrictions were observed. Imaging examinations were normal in 100%. The temporal pattern was either chronic or remitting, with acute exacerbations. Pain increased at night in 55%. A total of 62% presented concurrent headaches. Locally injected corticosteroids relieved the pain within 48 hours in 95% and also improved concurrent headaches, by decreasing attack frequency and analgesics intake. Placebo was not helpful. Relapses were observed in 45% (average 8 months).Conclusions: The trochlear region is the origin of a specific and unrecognized headache, which we have named primary trochlear headache. Local treatment on the trochlear area is also useful for other concurrent primary headaches with inadequate response to oral therapy.