The median latency period for a favorable response or headache worsening was 1 day after the injection. Patients reported no serious adverse events following treatment. One-third of subjects reported mild adverse events, mostly self-limited tenderness at the injection site, neck stiffness, and dizziness. No cutaneous atrophy or alopecia occurred after the injection.
Responders to the first injection were offered a second after 3 months, an interval chosen to minimize the risk of side effects due to overexposure to steroids. Among 45 patients treated a second time, 19 had a complete response and 16 a partial response with greater than 50% improvement. The median response duration was 18 days.
Three months later, 28 patients had a third ONB. Eleven showed a complete response and nine were partial responders, with a median response duration of 25 days.
Fourteen patients received a fourth injection, resulting in complete response in seven and partial response in three. The response duration averaged 23 days.
"Given the good tolerability profile when this simple procedure is performed every 3 months, occipital nerve blocks can play a useful role in the management of chronic cluster headache, allowing for periods of relief from an otherwise highly disabling disorder," she concluded.
Cluster headache is a rare disorder characterized by attacks of unilateral pain, typically orbital, supraorbital, and/or temporal. The attacks generally last from 15 minutes to 3 hours. They occur with a frequency ranging from once every day or 2 up to eight per day. Episodic cluster headache occurs in skeins running for weeks to months, followed by remission periods that can last for months.
Dr. Gaul and Dr. Abu Bakar reported having no financial conflicts.