Quantitative sensory testing may predict response to sphenopalatine ganglion pulsed radiofrequency treatment in cluster headaches: a case series.

Pulsed radiofrequency treatment has been described as a nonablative alternative to radiofrequency thermocoagulation for the management of certain chronic pain syndromes. We present our first three patients with long-standing cluster headaches who were treated with pulsed radiofrequency to the sphenopalatine ganglion. All three patients have had cluster headaches for more than 10 years' duration and experienced minimal relief with conservative treatment. An excellent midterm effect was achieved in two of the three patients and a partial effect in one. No neurological side effects or complications were reported. Quantitative sensory testing consisting of allodynia testing, pressure-pain thresholds, electrical pain thresholds, and conditioned pain modulation (CPM) response testing were used to monitor their sensory processing changes before and after the procedure. From this case series, it might be that cluster headache patients with an impaired CPM response with or without signs of allodynia will respond less favorably to interventional treatment. Further studies are required to validate this hypothesis.