Pain Psychiatry of Trigeminal Neuralgia

In addition to the repeated episodes of paroxysmal, electrical facial pain classically associated with the disease, many patients with trigeminal neuralgia (TN) suffer from severe emotional distress. At present, there is no universally agreed pathophysiological explanation for the high incidence of depression and anxiety within this patient population. Despite the unclear understanding, the psychiatric comorbidities should be addressed as a part of comprehensive, multi-modal approach. Anticonvulsants or serotonin and norepineprhine reuptake inhibitors are viable pharmacological options that can supplement the currently used carbamazepine therapy. For medically refractory cases, surgical interventions are being suggested as effective alternatives in managing both the pain and the psychiatric complaints of TN. Examples include microvascular decompression, stereotactic radiosurgery, and repetitive transcranial magnetic stimulation. Continued research to understand TN should take into account the psychiatric burden in this population in order to promote a holistic treatment approach.

Endoscopic-Assisted Microvascular Decompression

Diseases of ephaptic transmission are commonly caused by vascular compression of cranial nerves. The advent of microvascular decompression has allowed for surgical intervention for this patient population. This chapter highlights the technique of endoscopic-assisted microvascular decompression for trigeminal neuralgia and hemifacial spasm. Endoscopy and keyhole techniques have resulted in a minimally invasive and effective treatment of symptoms for patients with neuralgia.

Novel Techniques for Trigeminal Neuralgia Including Trigeminal Neurostimulators

Several innovative surgical options for the management of trigeminal neuralgia have emerged over the past 40 years. In addition to microvascular decompression, other techniques have been introduced for the treatment of trigeminal neuralgia and facial nerve pain. This chapter describes the following novel therapeutic modalities: endoscopic microvascular decompression, radiosurgery, radiofrequency, thermocoagulation, glycerol rhizotomoy, balloon compression, Gasserian ganglion stimulation, and subcutaneous trigeminal nerve stimulation. For each of these techniques, this chapter provides a description of the procedure, criteria for patient selection, and discusses published data regarding patient outcomes.

V2 Rhizotomy

Trigeminal neuralgia is a facial pain syndrome characterized by excruciating, paroxysmal, electric shock-like pain attacks in the sensory distribution of the trigeminal nerve. Medical management remains the first line of treatment. When this fails, surgical management needs to be considered. Percutaneous interventional procedures such as glycerol rhizotomy, radiofrequency (RF) thermocoagulation, and balloon compression of the trigeminal ganglion and its branches are some of the most commonly used procedures as they avoid exposure to general anesthesia, provide successful short-term results, and are available to people with significant co-morbidities. Of these, RF is the most often used. The V2 and V3 branches of the trigeminal nerve are most commonly affected, and are thus the most frequent targets for RF interventions. These procedures may be performed using conventional fluoroscopic, ultrasound, or CT-guided imaging, including combined flat-panel CT and fluoroscopy. This chapter summarizes these common ablation techniques targeting the V2 branch of the trigeminal nerve.

Medical Management of Trigeminal Neuralgia

The first-line treatment of trigeminal neuralgia can be very effective, but side effects are often difficult for patients to tolerate. This chapter is a guide to the broad selection of medical therapies currently available for the treatment of trigeminal neuralgia which includes oral therapies and other non-surgical methods of treatment such as IV medications, nasal sprays, topical ointments, and injections. The discussion of each treatment includes discussion of its evidence in current literature, its proposed mechanism of action, its dosing and appropriate setting for clinical use, and its side effect profile.

Glycerol Rhizotomy as a Treatment Modality for Trigeminal Neuralgia

In this chapter, the authors discuss the use of glycerol rhizotomy (GR) as a treatment modality for trigeminal neuralgia. GR was first described by Håkanson and has been used for more than 40 years as a minimally invasive, safe option for the management of facial pain. Here, the authors discuss the history behind the discovery of GR, relevant biochemical mechanisms of neurolysis, indications, a step-by-step procedural outline for GR and intraoperative cisternography, potential side effects, efficacy of treatment, and new applications for the imaging technique. GR has stood the test of time in neurosurgery, and this chapter demonstrates its utility in patients who are poor surgical candidates for microvascular decompression and for whom medical treatment has failed to manage their intractable pain.

Microsurgical Nuances in the Management of Trigeminal Neuralgia

Microvascular decompression (MVD) is a highly effective surgical treatment for patients with trigeminal neuralgia (TN) caused by arterial compression. In cases of TN without arterial compression of the nerve, however, a variety of other surgical treatments can be effective for pain relief including neurolysis, nerve section, and placement of a tentorial sling. In this chapter, the authors discuss the nuances of surgical interventions for TN outside of standard MVDs. They also explore recent innovations in MVD surgery for TN.

Open Microvascular Decompression

Microvascular decompression (MVD) is a neurosurgical procedure used to treat various neuralgias of the cranial nerves. The clinical presentation, natural history, pathophysiology, and medical management of trigeminal neuralgia, hemifacial spasm, glossopharyngeal neuralgia, and nervus intermedius neuralgia is reviewed. A thorough discussion on the retrosigmoid approach for decompression of cranial nerves is presented, along with newer techniques and controversies on adjuvant therapies and neuromonitoring. The surgical outcomes of MVD are discussed, along with alternative techniques to open MVD.

Classification Systems for Trigeminal Neuralgia and Quantification of Facial Pain

Trigeminal neuralgia is a rare syndrome classically described as brief paroxysms of severe, lancinating facial pain along a unilateral trigeminal nerve distribution. Numerous clinical presentations of trigeminal neuralgia exist, with various distinct etiologies. Several classification schemes have been designed for clinical and research purposes. However, varying terminology and inconsistent utilization of these systems can lead to diagnostic confusion and ungeneralizable research findings. Similarly, multiple pain scales have been used for trigeminal neuralgia with differing degrees of granularity, validity, and reliability. This chapter provides an overview of the commonly used classification systems and pain scales in the context of their evolution and utilization. Furthermore, the authors provide recommendations for application of these systems to clinical and research practice.

Radiosurgery for Trigeminal Neuralgia

Trigeminal neuralgia is a debilitating neuropathic condition characterized by recurrent paroxysms of shock-like pain across the distribution of the trigeminal nerve, often brought on by innocuous stimuli. Available therapies presently include symptomatic management using anti-convulsant drugs and invasive surgical procedures to target the pathogenic drivers of disease or ablate the trigeminal nerve. Radiosurgery is a treatment modality that offers a minimally invasive, low-risk alternative that has promising clinical utility in the management of refractory trigeminal neuralgia. Radiosurgical approaches like Gamma Knife (GKS) and Cyberknife (CK) utilize image-guided, algorithm-defined dose contouring to disrupt pathogenic pain signaling by delivering targeted amounts of radiation along different points on the trigeminal nerve. This chapter reviews the structure of radiotherapy paradigms, treatment protocol, major outcomes, associated risks, relative clinical utility, and areas of further research that underlie the use of CK and GKS in managing trigeminal neuralgia.