Peripheral nerve field stimulation for chronic neuropathic pain: a single institution experience.

BACKGROUND: Peripheral nerve field stimulation (PNFS) is a novel neurosurgical procedure consisting of implantation of subcutaneous leads in specific painful areas in different types of painful, drug-resistant syndromes. The objective of this study was to evaluate the efficacy of PNFS in several patients affected by different chronic neuropathic pain syndromes, along with its risks, limits and possible correlation between the results achieved and the patients' main symptoms. METHODS: Twenty-two patients affected by different types of chronic neuropathic pain were submitted to PNFS at the Department of Neurosurgery of the Istituto Neurologico "C. Besta" in Milan between July 2009 and July 2013. The visual analog scale (VAS) and variations in the use of analgesic drugs, along with complications, were considered to assess results. RESULTS: In 59 % of our patients, an average pain reduction of 5.50 points on the visual analog scale was observed (average pre-implant score 8.86 and average post-implant score 3.36). These patients reduced their analgesic drug use after PNFS. We observed no early or long-term complications after our last follow-up evaluation. CONCLUSIONS: PNFS can be considered an effective and safe option to treat carefully selected, drug-resistant and chronic neuropathic pain patients; the reversibility of the procedure and its lack, at least in our hands, of long-term complications may contribute to wider use of this procedure.

[Contribution of thalamotomy, cordotomy and dorsal root entry zone Caudalis trigeminalis lesions in the treatment of chronic pain]. / Le rôle de la thalamotomie, de la cordotomie et de la lésion de la dorsal root entry zone (DREZ) Caudalis trigeminalis dans le traitement de la douleur chronique.

Ablative neurosurgical methods are mainly proposed in cases of nociceptive pain, but, at present, medical treatments and local pharmacotherapy (intrathecal and intracerebroventricular) are often very effective in this context. Moreover, neuropathic pain is well controlled by äugmentative techniques, except painful paroxysms. If a destructrive method is necessary, it is selective, performed according to precise neurophysiological and anatomical data with the frequent use of percutaneous and/or stereotactic techniques: the lesion of caudalis DREZ in treatment of neuropathic trigeminal pain, the antero-lateral cordotomy in the treatment of unilateral severe cancer pain and several kinds of thalamotomy.

Life-threatening dystonia-dyskinesias in a child: successful treatment with bilateral pallidal stimulation.

We report a 13-year-old boy who developed severe, refractory dystonia-dyskinesias as an abrupt worsening of a previously nonprogressive movement disorder. The movements became continuous, requiring artificial respiration and continuous sedation in the intensive-care unit. Various drugs and drug combinations failed to achieve control. The child was then treated successfully with bilateral pallidal (GPi) stimulation as shown in the videotape. Four months later and without medication, the boy regained autonomous gait and audible speech; his neurologic condition continues to improve.

Italian multicentric study on pain treatment with epidural spinal cord stimulation.

A multicentric study on the treatment of nonmalignant chronic pain with epidural spinal cord stimulation (SCS) has been carried out in 32 Italian centers devoted to pain therapy. Neurosurgical and anesthesiology units participated in this retrospective study. 410 of the eligible patients were enrolled in the protocol: 48% were male, 52% female. All patients underwent a screening test period (average 21 days) and 74% underwent the definitive implant. The diagnosis was failed back surgery syndrome in 45%, reflex sympathetic dystrophy in 15%, phantom limb pain in 14%, postherpetic neuralgia in 8%, peripheral nerve injury in 5%, others 13%. 84% received noninvasive unsuccessful treatment (10 tensor acupuncture). All had previous pharmacological therapy which was not always discontinued when SCS took place. Pain assessment had been done with the visual analog scale and verbal scale both subjectively and by the physician and nurses. Neuropsychological profile with minimal mental test or MMPI was obtained in 68% of the patients. These results were favorable (i.e. excellent or good; more than 50% reduction of pain) in 87% of the patients at the 3-month follow-up, 75% at the 6-month follow-up, 69% at the 1-year follow-up, and 58% at the 2-year follow-up. Complication rate was: dislocation of the electrocatheter 4%, technical problems 3%, infections of the system 2%. The results will be discussed in correlation with the different etiologies of the nonmalignant chronic pain syndrome.