Progress in neurological surgery最新文献

Since its original introduction several decades ago, peripheral nerve stimulation (PNS) of the craniofacial region has been traditionally performed using devices intended for spinal cord stimulation applications with inevitably high rate of technical challenges and procedural complications. The lower invasiveness of recently developed wireless neurostimulation systems makes them much better suited for craniofacial applications. Here, we discuss the preliminary clinical data from several published reports and the ongoing multicenter prospective study of wireless PNS in the craniofacial region. Advances in wireless transmission of electrical signals may make wireless neurostimulation even more attractive in the future. Since most of the evidence supporting PNS for facial pain comes from small subsets of the population, case series and case reports, there will need to be larger, randomized controlled trials with cost efficacy analyses in order to validate the role of wireless PNS as the standard of care.

Non-invasive neuromodulation techniques such as transcranial direct current stimulation (tDCS) enable researchers and health care professionals to gain unique insight into brain functions and to treat a number of neurological and psychiatric conditions. Repeated applications of anodal tDCS over the primary motor cortex (M1) have been shown to produce long-lasting relief of neuropathic pain. tDCS is a technique that can induce and modulate brain plasticity and thus be suitable for treating diverse chronic pain conditions, disorders associated with substantial reorganization of central nervous system activity. The number of published basic research and clinical papers in this field is increasing exponentially, but the number of studies that include patients with facial pain is still limited, and there are no "gold standards" with regard to how to treat the various kinds of pain disorders. Pharmacoresistant facial pain is a substantial burden for the patient as manifested by its interference with daily functioning and reduced health status associated with pain severity. Without doubt, further trials are needed to optimize stimulation parameters and find effective protocols for this disorder. In addition, evaluation of the clinical effects of tDCS shows that low-intensity electrical stimulation techniques are exceptionally suitable for gaining further insight into the functional role of a given brain region, e.g. how brain processes emerge and can be altered in anatomically distributed, but functionally connected, brain networks.

Electro-modulation of subcortical deep brain structures by surgically implanted electrodes is now standard evidence-based treatment for movement disorders such as Parkinson's disease and essential tremor and is approved for dystonia and obsessive-compulsive disorder under a humanitarian exemption. Historically, deep brain stimulation (DBS) for multiple indications has demonstrated acceptable complication rates, rare mortality, and reducing morbidity as the technology and the techniques of its application have advanced. DBS for the amelioration of pain has been performed since the early 1950s, and became widely used in the 1970s, when targeting the somatosensory thalamus was shown to be efficacious for intractable pain syndromes including facial pain. The technique fell out of favour in the late 1990s after 2 multicentre trials failed to meet end-point criteria. Since these trials, DBS for pain has remained for investigational or "off-label" use. Criticisms from previous literature have involved unsuitability of patient selection, as well as inconsistencies in neurosurgical technique. Clinical success with DBS for facial pain has been for the treatment of a variety of chronic neuropathic and nociceptive pain syndromes; including trigeminal neuropathy, post-herpetic neuralgia, deafferentation facial pain, "atypical" facial pain, cluster headaches and other trigeminal autonomic cephalalgias, as well as head and neck pathologies, most often which have been resistant to all other 1st- and 2nd-line medical and surgical treatments, when DBS has become a "last treatment option." An enhanced understanding of the mechanisms of action of DBS for pain will enhance outcome, and appropriately prescribe evolving novel nuclear brain targets.

Trigeminal branch stimulation is a type of peripheral nerve stimulation (PNS) used to treat a variety of craniofacial pain disorders. Common indications include trigeminal neuralgia, trigeminal neuropathic pain, trigeminal deafferentation pain, trigeminal postherpetic neuralgia, supraorbital neuralgia, and migraine headaches. Supraorbital and infraorbital arrays are the most common electrode configurations, although preauricular, mandibular branch, and subcutaneous peripheral nerve field stimulation arrays have also been described. Trigeminal branch stimulation may be used as a stand-alone neuromodulation therapy or it may be combined with occipital nerve, sphenopalatine ganglion, or Gasserian ganglion stimulation to treat more complex pain patterns. Consistent with other forms of PNS, trigeminal branch stimulation is a minimally invasive, safe, and straightforward method of treating medically refractory neuropathic pain.

Neuropathic facial pain can be exceedingly difficult to manage with conventional therapies. Since this pain may be excruciating and often debilitating and some patients do not respond or do not tolerate conventional treatments, the interest in neuromodulation therapies is increasing. One of the most commonly used neuromodulation therapies, spinal cord stimulation, has recently shown promise in treating facial pain. We reviewed the current literature to determine usefulness of spinal cord stimulation in management of refractory facial pain. Our review indicates that for some patients with intractable pain in portions of the face, cervical spinal cord stimulation may be effective at reducing pain.

Percutaneous electrical nerve stimulation (PENS) is a novel, minimally invasive and useful treatment modality. Its use in complex facial pain has been on the rise, and its utility will further increase with the advances in the technology and renewed interest in the field of peripheral neuromodulation. PENS therapy can be used both as diagnostic and therapeutic option. The precise mechanism of action is not known, although a combination of electrical neuromodulation and release of endogenous morphine-like substance in the central nervous system appears as plausible explanation. We analyse the various studies in the literature and discuss the Southampton data regarding facial pain treatment with PENS therapy. We believe that PENS therapy for facial pain and headache is currently underutilised. It is safe, economical and should certainly be part of the armamentarium in the treatment of complex facial pain and headache.

Transcutaneous electrical nerve stimulation (TENS) has been used for its analgesic effects for chronic pain, including facial pain. Here, we summarize how the electrical stimulation of branches of the trigeminal nerve via TENS has been utilized to reduce pain resulting from trigeminal neuralgia, temporomandibular joint disorder, migraine and other headache types, and ocular pain sensations. TENS has been used for both short-term (one session) and long-term (multiple sessions) pain control with little to no adverse effects reported by subjects. The results of the summarized studies suggest TENS is an effective non-invasive, non-pharmacologic means of pain control for patients with facial pain conditions.

Although commonly seen in the clinical practice, chronic orofacial pain quite often does not have a clear unambiguous organic origin. It may be difficult to find optimal pharmacotherapy, and in many cases, this pain may become pharmacotherapy resistant. Neuromodulation, particularly with electromagnetic neurostimulation techniques, has been widely used for the treatment of different types of pharmacoresistant pain, and repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) exemplify readily available noninvasive neuromodulation methods. We have used rTMS and tDCS to treat pharmacoresistant chronic orofacial pain. rTMS uses an electromagnetic coil placed over the patient's head to induce electrical current impulses within the brain tissue, thereby modulating brain activity. In tDCS, an electrode placement location(s) must be chosen in accordance with the density and the time course of the current, mainly to prevent undesired pathological changes in the underlying tissue. Transcranial neuromodulation methods provide a nondestructive and reversible approach to treatment of severe and otherwise uncontrollable chronic orofacial pain. These methods may be curative - as a part of so called "reconstructive neurosurgery" stimulation of neural structures may be used as an alternative to surgical destruction of neural pathways.