Trigemino-Cervical Neuropathic Pain Relieved by Serially Repeated Peripheral Nerve Field Stimulation Without Tolerance: Case Report.

BACKGROUND: With its relative simplicity and safety, peripheral nerve field stimulation (PNFS; PENS) is contributing to the re-emergence of peripheral nerve stimulation as an effective therapy for neuropathic pain (NPP). CASE PRESENTATION: A 70-year-old woman had developed severe, medically refractory NPP unilaterally in the scalp and face 20 years earlier, following a maxillofacial surgical procedure. PNFS gave substantial relief of the pain and allodynia and was repeated successfully on a further 25 occasions over the subsequent five years. Tolerance did not develop. CONCLUSION: Serially repeated PNFS can provide sustained relief of NPP over long periods, without tolerance, where a permanent implant may be inappropriate, unavailable, or declined.

Hemibody pain relieved by microvascular decompression of the contralateral caudal medulla: case report.

Microvascular decompression (MVD) of cranial nerves has become an established treatment for trigeminal and (vago)glossopharyngeal neuralgia and for hemifacial spasm. The authors present the case of a 64-year-old man who had a 3.5-year history of severe, drug-resistant hemibody pain with sensory and autonomic disturbance. The ipsilateral trigeminal, cochlear, and glossopharyngeal function also was affected. The contralateral posterior inferior cerebellar artery was seen on magnetic resonance imaging to be indenting the caudal medulla anterolaterally, causing displacement. After MVD of the medulla, there was an immediate and complete resolution of the pain and almost complete resolution of the sensory and autonomic disturbances. The pain later recurred mildly and transiently. The residual symptoms had resolved by 2 years.

Incidence and avoidance of neurologic complications with paddle type spinal cord stimulation leads.

INTRODUCTION: While reference is frequently made to the risk of spinal cord or nerve root injury with the surgical implantation of paddle type spinal cord stimulation (SCS) electrodes, data are lacking on the frequency, causes, and prevention of these complications. METHODS: To determine the incidence and frequency of neurologic complications, we performed 1) a comprehensive analysis of the literature to determine the incidence of complications that have caused or could lead to neurologic injury; 2) an analysis of the US Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) data base; and 3) an investigation of manufacturers' data on surgically implanted paddle electrodes. We then convened an expert panel of neurosurgeons experienced in the surgical implantation of paddle electrodes to provide recommendations to minimize the risk of neurologic injury. RESULTS: The scientific literature describes the breadth of neurologic complications that can result from SCS electrode implantation but does not provide interpretable data with respect to the incidence and frequency of these complications. The MAUDE data base is not constructed to be sensitive or specific enough to provide these critical data. Primary data show a risk of neurologic injury from implantation of paddle electrodes below 0.6%. DISCUSSION: Preoperative, intraoperative, and postoperative measures to further minimize this risk are described. CONCLUSIONS: This investigation, the first comprehensive evaluation of the incidence and frequency of neurologic injury as a result of SCS paddle electrode implantation, suggests that neurologic injury is a rare, but serious, complication of SCS. The incidence of these complications should be decreased by the adoption of approaches that improve procedural safety and by careful patient follow-up and complication management. Physicians should be aware of these approaches and take every precaution to reduce the risk of neurologic injury. Physicians also should report any adverse event leading to injury or death and work together to improve access to these data.

Efficacy of spinal cord stimulation for neuropathic pain: assessment by abstinence.

Assessment of the efficacy of spinal cord stimulation (SCS) against neuropathic pain remains problematic. Some patients may underestimate this, as revealed by their reaction to stimulator malfunction. This study investigated whether abstinence from SCS would provide an indication of its effectiveness. Patients were invited to complete two brief questionnaires each day for 50 days including two periods of 14 days without stimulation. Pain level, sleep quality, activity level and drug intake were recorded. Of 75 patients thought to be using their stimulators, 12 did not respond to the invitation, eight had unresolved technical problems and one no longer needed SCS. Of the 54 remaining, 10 did not wish to be without SCS and 15 declined without giving a reason. Thus 29 agreed to take part but three then dropped out through illness and questionnaires were not received from 10. Ten returned completed questionnaires but failed to follow the protocol; five of these were unable to leave their stimulators off. Only six took part correctly. Twenty of the 29 had received a preliminary explanatory home visit and for nine this was done by telephone. The former produced a considerably higher yield. All six who completed the study correctly had statistically significantly lower pain scores during stimulation. Four had improved sleep but only one reduced his medication and none of the six increased their activity levels. Correlation with previous clinical assessments is discussed. It is concluded that the abstinence principle might provide a useful tool but its power is very methodology-dependent.

Cervical spinal cord stimulation for pain: a report on 41 patients.

The objectives of this study were to assess the effectiveness of cervical spinal cord stimulation in the management of intractable pain syndromes affecting the upper limb and face and to assess the reliability of a specific electrode system in this mobile environment. Forty-one patients, aged 26-76 years (median 48) with neuropathic or ischemic pain underwent the cervical epidural implantation of identical dual two-contact paddle (four contacts per system) laminectomy electrodes. Follow-up (from 5 months to 11 years, 3 months; median 4 years, 7 months) was by multiple consultations carried out by the surgeon and/or in a nurse-led specialist clinic. Overall, 68% obtained sustained pain relief, rated as significant in 51% of the total. Facial pain did not respond. Ischemic syndromes responded well. Lead fracture rate was 15% of the original (11% of the total including replacements) and only 7% (5%) became dislodged.We conclude that the electrode system described provides reliable and sustained cervical cord stimulation. The outcomes are comparable with thoracic cord stimulation for neuropathic and ischemic syndromes.