occipital stimulation in refractory occipital neuralgias : a single- institution study of 60 patients in France and review of the litterature Sylvie Raoul(1, 2),, Emmanuelle Kuhn (2 ),Edwige de Chauvigny (2 ), Jean Michel N Guyen (3) Julien Nizard (2) Jean-Paul Nguyen (1) (1)Service de Neurochirurgie, Centre Hospitalier Universitaire Nantes, UIC 22 et EA3826, Nantes, France (2)Centre d Evaluation et de Traitement de la Douleur, Centre Fédératif Douleur-Soins de Support-Ethique Clinique, UIC 22 et EA3826, Centre Hospitalier Universitaire Nantes, France (3)Service de Biostatistique, Centre Hospitalier Universitaire Nantes, France
Objectif Occipital nerve stimulation (ONS) is effective to treat various headache such as Cluster headache, migraine, sunct and hemicrania paroxystic. Many studies focus on migraine and cluster headhache. The efficiency of ONS was less evaluated in occipital nevralgia. There is no prospective study in the literature and report of cases do not exceeded 30 cases. Methods A review of prospectively collected datas included 60 patients with intractable occipital neuralgias treated with peripheral nerve stimulation (PNS) was performed during a period from October 2008 to October 2014. Pain evaluation, location, duration, cause and previous treatment were analyzed. Evaluations include Visual Analogic Scale (VAS) before and after PNS implantation, the Medical Quantification Scale (MQS) before and after implantation, failure of medical treatment and multidisciplinary approach of pain. External trials with transcutaneous electric neurostimulation (TENS) were performed to evaluate if the trial is successful (patient reported at least 50% decrease of pain on VAS during one month). 60 patients were implanted and results at 6 months were analyzed. Résultats At the time of follow-up 78 % of patients have 50% of decrease pain on VAS. Mean VAS was 8.4/10 preoperatively compare to 2.85/10 after PNS implantation. Results are quite stables with time even if parameters settings need to be adjusted frequently. Oral pain medication was reduced to about 50%. The MQS was equal to 18 preoperatively and was decreased to 9.9 in postop. Side-effects included 4 patients with infection of the
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Figure 1 placement of stimulation
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system (6%), and 4 migrations of electrode (6%). Parameter settings varied from 44 to 60 Hz, 90 to 325µs and 1.5 to 6.6mA.
Techniques chirurgicales: -open surgery (less migration of the electrode, les fracture of the lead , less current used) - risks: general anaesthesia, infections (2 à 5% dans le service de neurochirurgie) and hematomas.
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Figure 2 EVA preop and postop
MQS preop andpostop
Conclusion Occipital nerve stimulation is effective to treat patients with occipital neuralgias. The result of this largest serie in France show that PNS for intractable occipital neuralgias is safe and reversible treatment with few side-effects and must be proposed to patients with occipital neuralgias which are failed with conservative medical treatment.
