Objectives Primary headache disorders are common, but many patients are refractory to medical treatment. PENS therapy involves the stimulation of one or more individual nerves or dermatomes using needle probes. We assessed whether a ‘single shot with single probe’ strategy would benefit patients with refractory headache disorders, including chronic migraine (CM), and chronic cluster headache (CCH).

Design Service evaluation of 36 patients treated with PENS therapy between September 2012 and June 2016. Follow-up data was available for 33 patients.

Subjects 16 patients with CM, nine with CCH, and one with hemicrania continua. Secondary headaches comprised occipital neuralgia, cervicogenic headache, and trigeminal neuropathy.

Methods PENS was given using Algotec® disposable 21 gauge PENS therapy probes (8 cm) to the occipital nerve ipsilateral to the pain (or bilaterally in cases of bilateral pain). Stimulation was delivered at 2 Hz/100 Hz, at 3 cycles/second, between 1.2–2.5 V depending on patient tolerability, for 25–28 min.

Results 6/9 patients with CCH improved significantly after the first session. In all patients with CCH, PENS therapy was well tolerated, with no significant adverse events reported. One patient with CCH reverted to episodic cluster. Only four patients with CM experienced any benefit.

Conclusions PENS therapy shows potential as a relatively non-invasive, low-risk, and inexpensive component of the treatment options for refractory primary headache disorders, particularly chronic cluster headache.