Incidence of neuropathic pain after radiofrequency denervation of the third occipital nerve.

The purpose of this study was to identify the incidence of neuropathic pain occurring after radiofrequency neurotomy of the third occipital nerve (TON). This study was conducted at a teaching hospital from January 1, 2008, to March 31, 2010. With institutional review board approval, Current Procedural Terminology codes were used to identify patients who received radiofrequency ablation (RFA) of the nerves supplying the C2-3 facet joint and the TON. The C3 dorsal ramus provides innervation to the C2-3 facet joint and the suboccipital cutaneous region, and procedures that included ablation to this region were reviewed for complications. Postprocedural data were collected by reviewing follow-up appointment notes and telephone calls. Included were patients who had new neuropathic pain in the distribution of the TON after RFA. They described what they were feeling as burning, tingling, or numbness. All patients who presented with complaints had normal neurologic findings and no secondary cause for their symptoms. The included patient medical records were then reviewed for severity and duration of symptoms and the need for treatment with pain medication. Sixty-four patients underwent C2-3 RFA or TON RFA, and 12 patients were identified as experiencing ablation-induced third occipital neuralgia, an incidence rate of 19%. This finding suggests that patients undergoing RFA of the nerves supplying the C2-3 joint or TON are at risk for postprocedural third occipital neuralgia. This possibility may affect providing informed consent as well as anticipating and managing postprocedural pain.

Meningismus associated with malpositioned intraspinal catheter for drug delivery.

BACKGROUND: Implanted delivery systems for intrathecal drug administration have become more common in the management of nonmalignant pain. Many postprocedural complications have been described in the literature including infection and headache provoked by position changes. Determining the etiology of a postimplant headache is important particularly when considering the possibility of a life-threatening infection. CASE REPORT: We present a patient who underwent placement of an implantable drug delivery system (IDDS) for intractable abdominal pain that developed positional headaches, and significant neck and back pain. Attempted cerebrospinal fluid aspiration reproduced her symptoms and imaging revealed a malpositioned intraspinal catheter tip approximated to the meninges. Revision of the system completely relieved her symptoms. CONCLUSION: Meningismus from malpositioned catheters is a rare complication that can mimic meningitis but should be considered in the differential for postimplant headaches. Given the increased use of IDDS, it is important to recognize and evaluate postimplant complication and treat it appropriately. We discuss this case report and appropriate work-up and differential diagnosis for meningismus following implant.