Gamma Knife for Trigeminal Neuralgia

Trigeminal neuralgia (TN),

also known as tic douloureux, is a pain syndrome recognizable by patient history alone. The condition is characterized by intermittent one-sided facial pain. (Read the review article here.) The pain of trigeminal neuralgia typically involves one side (>95%) of face (sensory distribution of trigeminal nerve (V), typically radiating to the maxillary (V2) or mandibular (V3) area). Physical examination findings are typically normal; although mild light touch or pin perception loss has been described in central area of the face. Go the the following links:

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Anatomy
anatomy of V nerve, anatomy with labels, more anatomy. anatomy from Gray's, brainstem anatomy,

Imaging: MRI, MRI#2, MRI#3, MRI#4, MRI#5 , MRI target , more MRI anatomy: here, here, here, here , here, here, here

Disease: More about Trigeminal neuralgia, atypical trigeminal

Radiosurgery: Gamma Knife Results, Gamma Knife Studies and Links, Studies: here and here

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Trigeminal neuralgia (TN), or tic douloureux, is a chronic, episodic facial pain syndrome, with onset most commonly in the sixth or seventh decades of life. It affects about 4.3 per 100,000 people annually, and is often debilitating. It can involve one or more divisions of the trigeminal nerve, and is characterized by five classical features being: paroxysmal, provokable, unilateral, confined to the trigeminal nerve domains, and unassociated with gross trigeminal motor or sensory loss.

The etiology of TN has been ascribed to a blood vessel compressing the trigeminal root at its junction with the pons, thus altering axonal transmission. However, only rarely is an anatomic abnormality demonstrable on imaging studies, either in the peripheral or central pathways of the affected trigeminal nerve.

The initial management of tic pain consists of medical therapy, such as carbamazepine, phenytoin, gabapentin, or baclofen. When medical therapy is ineffective or causes intolerable side effects, surgical intervention becomes necessary. In general patients should start with medication first (go here) before considering radiosurgery. The most commonly used medications include Tegretol, Trileptal, Lamictal, Lyrica and Neurontin (go here).

Surgical options include decompression of the affected nerve (retromastoid craniectomy with microvascular decompression of the trigeminal nerve) and various percutaneous rhizotomies of the trigeminal nerve using heat, mechanical compression, radiation, or osmotic injury to interrupt the pain transmission. Microvascular decompression entails higher operative risks, and trigeminal rhizotomy procedures are associated with deafferentation of the face. Although microvascular decompression is a potentially curative procedure for eligible healthy patients, many patients with tic douloureux are elderly or have medical contraindications to invasive surgery. Approximately 30% of patients who undergo initial microvascular decompression eventually have a relapse. Retrogasserian radiosurgical rhizotomy is a relatively noninvasive and safe procedure that is suitable for patients with and without a history of prior surgery