Occipital nerve stimulation for intractable occipital neuralgia: an open surgical technique.

Abstract

Occipital neuralgia (ON) is defined as a paroxysmal jabbing pain in the cutaneous distribution of the greater or lesser occipital or third occipital nerve.10 The pain is frequently described as sharp, shooting, stabbing or electrical, preferentially unilateral and remitting, radiating to the occipital and frontal areas, with associated symptoms suggesting a pain origin from the neck.2,3 ON tends to become chronic and must be distinguished from referred pain to the occiput. Etiologies of occipital neuralgia include traumatic (72% of this series), degenerative (14% of this series), and oncological or idiopathic (14% of this series). Most cases arise from a flexion-extension injury to the neck (i.e., whiplash), which commonly results from a rear-end motor vehicle collision.8 Treatment modalities for ON vary from conservative measures, which are usually the frontline treatments, to injections and surgical interventions. Injections such as regional anesthetic nerve block are initially effective in the majority of cases and are also helpful as a diagnostic tool.5,19,28 More recently, botulinum toxin A injection has been used with varied results,4,14 and a recent systematic review was equivocal because of the small number of patients.24 Surgical approaches are indicated for medically intractable ON and are often considered as the last resort. Surgical modalities include decompressive, ablative, and stimulating procedures. The clinical efficacy of these procedures varies, and each has complications of its own. Electrical stimulation of the occipital nerve has been previously reported as a nonablative modality to treat ON.6,9,12,20–22,27 The techniques described for stimulation of the occipital nerve use a fluoroscopic percutaneous approach to insert the stimulating electrode. However, this blind approach does not ensure that the electrode is directly in contact with the nerve trunk. The reported efficacy varies between 60% and 90% of pain relief21 and can diminish substantially with malpositioning or migration of the electrode lead. It is known that percutaneous occipital electrodes are prone to migration with subsequent loss of stimulation and often need surgical revision,13 even after meticulous anchorage techniques.7 Migration rates are study dependent, ranging from zero to 100%, with an average of approximately 15%; the readers are referred to a systematic review on implanted occipital nerve stimulators by Jasper et al.11 for more details. We postulate that suboptimal positioning of the electrode in relation to the nerve trunk and migration of the percutaneously placed electrode in the highly mobile cervical region are the reasons for loss of stimulation. In an attempt to solve the problem of electrode positioning and migration, we developed an open surgical approach that allows visualizing the occipital nerve and ensures meticulous anchoring of the electrode onto the main trunk of the nerve.