Burst Occipital Nerve Stimulation for Chronic Migraine and Chronic Cluster Headache.

BACKGROUND: Occipital nerve stimulation (ONS) is widely used for headache syndromes including chronic migraine (CM) and chronic cluster headache (CCH). The paraesthesia associated with tonic stimulation can be bothersome and can limit therapy. It is now clear in spinal cord stimulation that paraesthesia-free waveforms can produce effective analgesia, but this has not been reported in ONS for CM or CCH. MATERIALS AND METHODS: Seventeen patients (12 CM and 5 CCH) were treated with bilateral burst pattern ONS, including 4 who had previously had tonic ONS. Results were assessed in terms of the frequency of headaches (number of headache days per month for CM, and number of attacks per day for CCH) and their intensity on the numeric pain rating scale. RESULTS: Burst ONS produced a statistically significant mean reduction of 10.2 headache days per month in CM. In CCH, there were significant mean reductions in headache frequency (92%) and intensity (42%). CONCLUSION: Paraesthesia is not necessary for good quality analgesia in ONS. Larger studies will be required to determine whether the efficacies of the two stimulation modes differ. Burst ONS is imperceptible and therefore potentially amenable to robustly blinded clinical trials.

Burst or Conventional Peripheral Nerve Field Stimulation for Treatment of Neuropathic Facial Pain.

BACKGROUND: Trigeminal Neuropathic Pain (TNP) is a chronic facial pain syndrome caused by a lesion or disease affecting one or more branches of the trigeminal nerve. It may, for example, result from accidental injury to a branch of the trigeminal nerve by trauma or during surgery; it may also be idiopathic. TNP is typically constant, in contrast to most cases of the commoner trigeminal neuralgia. In some cases, pain may be refractory to pharmacological treatment. Peripheral nerve field stimulation is recognized as an effective minimally invasive surgical treatment option for this debilitating condition. To date, stimulation has used conventional tonic waveforms, which generate paraesthesia in the stimulated area. This is the first report of the use of paraesthesia-free burst pattern stimulation for TNP. METHODS: Seven patients were treated at the John Radcliffe Hospital for TNP from 2016 to 2018. Mean duration of preoperative symptoms was five years. All patients had exhausted pharmacological measures to limited effect. The initial three patients had tonic stimulation with the subsequent four having burst stimulation. Outcome was assessed using the numeric pain rating scale preoperatively and postoperatively at three and six months and one year. Side-effects and complications were also assessed as well as reduction in analgesic medication use. RESULTS: All patients achieved pain reduction of at least 50% at 6 months (range 50-100%, mean 81%, p = 0.0082). Those in the burst stimulation group were paraesthesia free. One patient developed a postoperative infection for which the system had to be removed and is awaiting reimplantation. There were no other complications in either group. CONCLUSION: Burst stimulation conferred similar pain control to tonic stimulation in our small cohort, and there were similar reductions in pain medication use. An additional benefit of burst stimulation is freedom from paraesthesia. Larger scale studies are needed to further evaluate burst stimulation and compare its efficacy with that of tonic stimulation.

Successful treatment of pelvic girdle pain with dorsal root ganglion stimulation.

The authors report the first case of successful implantation of a dorsal root ganglion stimulator at L1 and L2 for sustained improvement in chronic pelvic girdle pain.

Tractography Study of Deep Brain Stimulation of the Anterior Cingulate Cortex in Chronic Pain: Key to Improve the Targeting.

BACKGROUND: Deep brain stimulation (DBS) of the anterior cingulate cortex (ACC) is a new treatment for alleviating intractable neuropathic pain. However, it fails to help some patients. The large size of the ACC and the intersubject variability make it difficult to determine the optimal site to position DBS electrodes. The aim of this work was therefore to compare the ACC connectivity of patients with successful versus unsuccessful DBS outcomes to help guide future electrode placement. METHODS: Diffusion magnetic resonance imaging (dMRI) and probabilistic tractography were performed preoperatively in 8 chronic pain patients (age 53.4 ± 6.1 years, 2 females) with ACC DBS, of whom 6 had successful (SO) and 2 unsuccessful outcomes (UOs) during a period of trialing. RESULTS: The number of patients was too small to demonstrate any statistically significant differences. Nevertheless, we observed differences between patients with successful and unsuccessful outcomes in the fiber tract projections emanating from the volume of activated tissue around the electrodes. A strong connectivity to the precuneus area seems to predict unsuccessful outcomes in our patients (UO: 160n/SO: 27n), with (n), the number of streamlines per nonzero voxel. On the other hand, connectivity to the thalamus and brainstem through the medial forebrain bundle (MFB) was only observed in SO patients. CONCLUSIONS: These findings could help improve presurgical planning by optimizing electrode placement, to selectively target the tracts that help to relieve patients' pain and to avoid those leading to unwanted effects.

Successful treatment of testicular pain with peripheral nerve stimulation of the cutaneous branch of the ilioinguinal and genital branch of the genitofemoral nerves.

OBJECTIVES: To assess the effect of peripheral nerve stimulation on neuropathic testicular pain. MATERIAL AND METHODS: A 30-year-old man with a four-year history of chronic testicular pain following scrotal hydrocele surgery had two percutaneous leads implanted in his groin and low-frequency stimulation of the cutaneous branch of the ilioinguinal and genital branch of the genitofemoral nerves. RESULT: At seven-month follow-up, the pain intensity had declined from 9/10 to 2/10 on the numeric rating scale. CONCLUSION: We report the successful implantation of an ilioinguinal and genitofemoral nerve stimulator for sustained suppression of intractable neuropathic testicular pain.

Managing chronic neuropathic pain: the role of spinal cord stimulation.

In October 2008 the National Institute for Health and Clinical Excellence issued guidance supporting the use of spinal cord stimulation for people with chronic neuropathic pain, considering it to be a cost-effective use of resources within the NHS. This paper will provide an overview of chronic neuropathic pain. Spinal cord stimulation (SCS) will be explained, including the physiological mechanism and technology behind this treatment. The recent NICE guidance will be discussed along with information relating to the potential impact the guidance will have on Primary Care Trusts, GPs and community practitioners. A guide is provided for clinicians in primary care regarding access to this treatment and routes for referral.