Progress in neurological surgery
-
The interest for the sphenopalatine ganglion (SPG) in neurovascular headaches dates back to 1908 when Sluder presented his work on the role of the SPG in 'nasal headaches', which are now part of the trigeminal autonomic cephalalgias and cluster headache (ICHD-III-beta). Since then various interventions with blocking or lesional properties have targeted the SPG (transnasal injection of lidocaine and other agents, alcohol or steroid injections, radiofrequency lesions, or even ganglionectomy); success rates vary, but benefit is usually transient. ⋯ Moreover, in some patients SPG stimulation has been associated with a significant and clinically meaningful reduction in cluster headache attack frequency; this preventive effect of SPG stimulation warrants further investigation. For migraine attacks, the outcome of a proof-of-concept study using a temporary electrode implanted in the pterygopalatine fossa was less encouraging; however, an ongoing multicenter trial is evaluating the efficacy of long-term SPG stimulation against sham stimulation for acute and preventive treatment in patients with frequent migraine.
-
The number of peripheral nerve stimulation (PNS) indications, targets, and devices is expanding, yet the development of the technology has been slow because many devices used for PNS do not have formal regulatory approval. Manufacturers have not sought Food and Drug Administration (FDA) approval for PNS devices because of a perceived lack of interest amongst practitioners and patients. Without FDA approval, companies cannot invest in marketing to educate the implanters and the patients about the benefits of PNS in the treatment of chronic pain. ⋯ As the targets and indications for PNS continue to expand, there will be an even greater need for customized technological solutions. It is up to the medical device industry to invest in the design and marketing of PNS technology and seek out FDA approval. Market forces will continue to push PNS into the mainstream and physicians will increasingly have the choice to implant devices specifically designed and approved to treat chronic peripheral nerve pain.
-
Some of the more common peripherally mediated pain disorders are postamputation stump pain and phantom pain. These disabling conditions have proven difficult to treat. Here we aim to illustrate an option to treat postamputation pain using peripheral neurostimulation techniques. ⋯ Each of the tested patients reported that HFAC block provided the most significant amount of pain reduction they had ever experienced when compared to other pain modalities tried since their amputations. The high-frequency electric nerve block technique is currently investigational pending FDA clearance. The next step for this modality is a pivotal trial, with the goal of having this therapy available to the mass market upon FDA clearance.
-
Peripheral nerve stimulation (PNS) generally refers to stimulation of a named nerve via direct placement of a lead next to the nerve either via a percutaneous or open approach; in peripheral nerve field stimulation (PNFS), leads are subcutaneously placed to stimulate the region of affected nerves, cutaneous afferents, or the dermatomal distribution of the nerves which converge back to the spinal cord. Recently, there has been a renewed interest in using the PNS approach for many otherwise refractory pain conditions; however, PNFS appears to be more effective for the management of low back pain and therefore more attractive. ⋯ Our experience and the published studies provide evidence that PNFS is a safe and well-tolerated pain control option for intractable pain conditions, including chronic low back pain. Notably, achieving efficacious pain relief relies on correct patient selection and the optimal placement of the leads, ensuring, in particular, a lead depth of 10-12 mm from the surface to maximize the target sensation (mediated by fast-adapting Aβ fibers) of PNFS, which is believed to be most effective for the pain relief.
-
Peripheral nerve stimulation (PNS) has been in use for over 50 years to treat patients suffering from chronic pain who have failed conservative treatments. Despite this long history, the devices being used have changed very little. In fact, current PNS technology was developed specifically for spinal cord stimulation. ⋯ The following chapter provides an overview of PNS technology throughout the years, outlining both the benefits and limitations. We will briefly explore the electrophysiology of PNS stimulation, with an emphasis on technology and indication-specific devices. Finally, design and technical requirements of an ideal PNS device will be discussed.