TRIGEMINAL NEURALGIA(TIC DOULOUREUX)

Trigeminal neuralgia is a condition of the fifth cranial nerve that is characterized by paroxysms of pain in the area innervated by any of the three branches ,but most commonly the third and the second branches of the trigeminal artery.the pain ends as abruptly as it starts and is described as a unilateral shooting or stabbing sensation.Associated involuntary contraction of the facial muscles can cause sudden closing of the eyes or twitching of the mouth,hence the name tic douloureux (painful twitch).

ETIOLOGY

• Vascular compression and pressure.
• Demylination of the trigeminal root.
• Paroxysms can occurwith stimulation of the terminals of the affected nerve branches such as washing the face,shaving,brushing the teeth,eating and drinking.A draft of cold air or direct pressure against the nerve trunk may also cause pain.Certain areas are called trigger points because the slightest touch shows paroxysm or episode.To avoid stimulating these areas patients with trigeminal neuralgia, try not to touch or wash the faces,shave,chew or do anything that may cause an attack.

CLINICAL MANIFESTATIONS

• Intermittent episodes of intense pain with sudden onset,The pain is rarely relieved by analgesics
• Tactile stimulation such as touch and facial hygiene and even talking will trigger an attack

DIAGNOSTIC EVALUATION

• History collection and physical examination
• Angiography ,CT Scan and MRI will identify a causative lesion.
• The actual diagnosis is made by history collection

MEDICAL MANAGEMENT

PHARMACOLOGICAL MANAGEMENT

• Antiseizure medications such as Carbamazepine(Tegretol),relieves pain in most of the patients with Trigeminal neuralgia by reducing the transmission of impulses at certain nerve terminals.Carbamezapine is usually taken along with meals.
• Serum levels should be monitored continuously
• Side effects includes nausea,vomiting,dizziness,drowsiness and aplastic anemia.
• The patient should be monitored continuously for bone marrow depression during long term therapy.
• Gabapentin(Neurontin)and Baclofen(Lioresal)is used for pain control
• Phenytoin can also be used.

SURGICAL MANAGEMENT

• Microvascular degeneration of the trigeminal nerve-An intracranial approach is used to relieve the contact between the cerebral vessel and the trigeminal nerve root entry.With the aid of an operating microscope,the artery loop is lifted from the nerve to relieve the pressure and a small prosthetic device is inserted to prevent recurrent impingement of the nerve.Although this procedure relieves facial pain while preserving normal sensation,the pain free interval averages only 1.9years with pain recurring in 47%of the patients within 1 hour of the surgery.
• Radiofrequency thermal coagulation-Percutaneous radiofrequency produces a thermal lesion on the trigeminal nerve.Although immediate pain relief is experienced,dysesthesia of the face and loss of corneal reflex occurs.Use of stereotactic MRI for identification of the trigeminal nerve followed by gamma knife radiosurgery is used.
• Percutaneous balloon microcompression-It distruptslarge mylineated fibres in all the three branches of the trigeminal nerve.After its placement the balloon is filled with a contrast agent for fluoroscopic examination.The balloon compresses the nerve root for one minute and provides microvascular decompression.

NURSING MANAGEMENT

• Preventing pain-Recognize the factors that alleviate the pain such as food that is too hot or too cold and jarring of the patient s bed on the chair. Even washing the face, combing the hair and brushing the teeth can produce acute pain. the nurse should assist the patient by providing education regarding how to decrease the pain.
• Provide cotton pads and room temperature water to wash the face.
• Instruct the patient to use mouth wash to cleanse the mouth after taking food if tooth brush causes pain., instruct the patient to do personal hygiene when there is no pain.
• The patient is instructed to eat the food at room temperature and to chew the food in the unaffected site, and to ingest soft foods.
• Provide psychological support.

PROVIDING POST OPERATIVE CARE

• Postoperative neurological assessments are conducted.
• The patient is instructed not to rub the eyes because the pain of a resulting injury willnot be able to find.The eye is assessed for redness.Artificial tears are instilled into the eyes if it is recommended.
• The patient is instructed not to chew on the affected site.

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