Etiology of Trigeminal Neuralgia

Case report: Teflon granuloma following microvascular decompression manifesting as light-triggered trigeminal neuralgia

Trigeminal Neuralgia is commonly triggered by stimuli in the area of the trigeminal nerve innervation. We report an exceptionally rare case of a 61-year-old woman who complained of recurrent trigeminal neuralgia, which sole trigger was seeing a bright light. Teflon felt that was placed on the nerve root in the initial surgery was suspected of causing this rare type of trigeminal neuralgia. A reflex circuit linking luminance to trigeminal nerve activity may be implicated in activating a trigeminal nociceptive pathway by a bright light trigger.

Role of cryotherapy in trigeminal neuralgia with certain modifications: A long-term prospective study

OBJECTIVE

The aim of this study was to investigate the application of cryosurgery with certain modifications as a treatment modality for patients diagnosed with trigeminal neuralgia refractory to pharmacologic treatments.

STUDY DESIGN

Forty-nine patients diagnosed with trigeminal neuralgia were treated with cryosurgery, involving the infraorbital nerve (13), inferior alveolar nerve (18), mental nerve (17), and supraorbital nerve (1), with closed, curved type of cryoprobe with nitrous oxide, at a temperature of -98°C, and pressure 70 kg/cm² or 100 psi.

RESULTS

Pain-free interval was observed to be less than 18 months in 4.08% patients, 36 to 40 months in 48.97% patients, 48 to 52 months in 32.65% patients, and greater than 52 months in 14.28% patients. All the patients experienced loss of fine and crude sensations for a period of 6 to 24 months.

CONCLUSIONS

Cryotherapy could be a safe and economic modality that can be repeated, if required.

Trigeminal Neuralgia, Glossopharyngeal Neuralgia, and Myofascial Pain Dysfunction Syndrome: An Update

Neuropathic pain is a common phenomenon that affects millions of people worldwide. Maxillofacial structures consist of various tissues that receive frequent stimulation during food digestion. The unique functions (masticatory process and facial expression) of the maxillofacial structure require the exquisite organization of both the peripheral and central nervous systems. Neuralgia is painful paroxysmal disorder of the head-neck region characterized by some commonly shared features such as the unilateral pain, transience and recurrence of attacks, and superficial and shock-like pain at a trigger point. These types of pain can be experienced after nerve injury or as a part of diseases that affect peripheral and central nerve function, or they can be psychological. Since the trigeminal and glossopharyngeal nerves innervate the oral structure, trigeminal and glossopharyngeal neuralgia are the most common syndromes following myofascial pain dysfunction syndrome. Nevertheless, misdiagnoses are common. The aim of this review is to discuss the currently available diagnostic procedures and treatment options for trigeminal neuralgia, glossopharyngeal neuralgia, and myofascial pain dysfunction syndrome.

Stereotactic mesencephalotomy for cancer - related facial pain

Cancer-related facial pain refractory to pharmacologic management or nondestructive means is a major indication for destructive pain surgery. Stereotactic mesencephalotomy can be a valuable procedure in the management of cancer pain involving the upper extremities or the face, with the assistance of magnetic resonance imaging (MRI) and electrophysiologic mapping. A 72-year-old man presented with a 3-year history of intractable left-sided facial pain. When pharmacologic and nondestructive measures failed to provide pain alleviation, he was reexamined and diagnosed with inoperable hard palate cancer with intracranial extension. During the concurrent chemoradiation treatment, his cancer-related facial pain was aggravated and became medically intractable. After careful consideration, MRI-based stereotactic mesencephalotomy was performed at a point 5 mm behind the posterior commissure, 6 mm lateral to and 5 mm below the intercommissural plane using a 2-mm electrode, with the temperature of the electrode raised to 80℃ for 60 seconds. Up until now, the pain has been relatively well-controlled by intermittent intraventricular morphine injection and oral opioids, with the pain level remaining at visual analogue scale 4 or 5. Stereotactic mesencephalotomy with the use of high-resolution MRI and electrophysiologic localization is a valuable procedure in patients with cancer-related facial pain.

Transcranial segment of the trigeminal nerve: macro-/microscopic anatomical study using sheet plastination

BACKGROUND

Trigeminal neuralgia (TN) may be caused by the mechanical compression of the trigeminal nerve. In the studies on the location of mechanical irritation and entrapment of the nerve, attention has been paid mostly to vascular structures in the subarachnoid space. Few studies have explored the relationship between the trigeminal nerve and its surrounding structures along its course in the skull base. The aim of this study was to examine and trace the root, ganglion and three divisions of the trigeminal nerve and their relationships with surrounding soft and bony structures in the skull base, and to identify the likely mechanical compression points.

METHODS

A total of 26 adult cadavers (ten females, 16 males; age range, 45-81 years) were examined in this study, eight for dissection and 16 for sheet plastination study.

RESULTS

Anatomical structures that may make the trigeminal nerve susceptible to entrapment in the skull base were located at (1) the inferolateral edge of the mouth of Meckel's cave, (2) the middle cranial fossa dura and the lateral wall of the anterior intracavernous portion of the internal carotid artery, (3) the ridge of the medial wall of the foramen rotundum, and (4) the twisted periosteum and venous plexus of the foramen ovale.

CONCLUSION

This study identified four likely mechanical compression points along the course of the trigeminal nerve in the skull base. Knowledge of these TN-susceptible sites may be useful to both skull base surgeon and TN-animal model researcher, particularly when they study TN without vascular compression.

Operative treatment of trigeminal neuralgia: review of current techniques

Surgical approaches to pain management are performed when medication cannot control pain or patients cannot tolerate the adverse effects of the medication. Microvascular decompression (MVD) is generally performed when the patient is healthy and relatively young. Partial sensory rhizotomy is performed in addition to, or instead of MVD, in patients in whom significant compression of the trigeminal sensory root does not exist or in whom MVD is technically not feasible. Three percutaneous ablative procedures and gamma knife radiosurgery (GKS) are also performed when MVD cannot be performed. The result of MVD is superior to that of the 3 ablative procedures. GKS is inferior to the 3 ablative procedures in terms of initial pain relief and recurrence, but superior in terms of complications. Peripheral procedures are usually performed in patients not suitable for or not wishing to have other procedures. However, no strict rules exist and each patient should be evaluated individually.