A Pilot Analysis on the Efficacy of Multiple Trigger-Point Saline Injections in Chronic Tension-Type Headache: A Retrospective Observational Study

This study aimed to investigate the efficacy of new targeted trigger-point injections (TPIs) using isotonic saline in patients with chronic tension-type headache (CTTH). Of 121 patients with headache who were retrospectively reviewed, 19 were included in this study and were categorized into two groups: those who received TPIs more than four times (group 1); and those who received TPIs less than, or equal to, four times (group 2). The patients received ultrasound-guided isotonic saline injections into the active trigger points once weekly. The primary outcome was an effect on headache intensity, determined using the visual analog scale (VAS), whereas the secondary outcome was an effect on quality of life, evaluated using the Henry Ford Hospital Headache Disability Inventory (HDI). The mean symptom duration of the 19 patients (11 men and 8 women; mean age, 52.5 years; and range, 23-81 years) was 16 months. The most frequently injected muscle was the splenius capitis. Patient demographics were similar between the two groups (p > 0.05). Simple linear regression revealed that symptom duration (p = 0.001) and baseline VAS score (p = 0.009) were significantly associated with the number of injections. At one month after the first injection, the mean VAS and HDI scores in group 2 were significantly lower than those in group 1 (p < 0.05), whereas the scores significantly decreased immediately after the last injection in both groups (p < 0.05). No adverse effects were reported in any patient. Our results indicate that the administration of new targeted TPIs using isotonic saline into the head and neck muscles of patients with CTTH can effectively relieve headache intensity and safely improve their quality of life.