Trigeminal Neuralgia/Tic Douloureux
An intense, usually unilateral, paroxysmal, stabbing pain in the distribution of the 5th cranial nerve.
- Typical onset: age 50
- Women more often affected than men
- If patient is less than age 40, consider multiple sclerosis (MS) a possible cause
- Pain is triggered with minor stimulation (e.g., tooth brushing, touching, or any routine activity in affected trigger areas)
- Patients appear in distress when experiencing painful episodes
- Early stages: pain may be rather mild (often described by patients as a twinge, dull ache, or burning sensation).
- Pain distribution:
- Sharp pain likely to appear all along the nerve pathway, followed by periods of remission during which no stimulus can elicit pain responses.
- Pain may be limited to the known distribution of one or more branches of the trigeminal nerve without motor deficit or (significant) sensory loss in the affected area
- Pain description:
- Extremely severe, electric shock-like or lancinating (e.g., sharp, jabbing) pain
- Episodic (short episodes)
- Site of pain depends upon the involvement of the nerve (typically involves the face, forehead, or eyes)
- Perform a thorough patient history
- Complete extraoral (head and neck) and intraoral (teeth, gingiva, and oral soft tissue) examination to rule out local pathology or source of pain. Diagnostic imaging should be used to complement this process.
- Pain from tooth: Rule out dentinal hypersensitivity, tooth fracture, secondary caries, or pulpitis prior to considering neuralgic pain. In some rare cases, a tooth itself can be a trigger point for trigeminal neuralgia, but all local pathologies must first be ruled out.
- Myalgia: Neuralgia and myalgia can be differentiated by clinical history of pain. In neuralgia, pain occurs with slight provocation, pain is sharp and radiates all along the nerve pathway. In myalgia, pain occurs with activity (e.g., opening mouth or yawning), pain is dull and does not radiate all along the nerve pathway.
- Local anesthetic injections can help identify affected branches of trigeminal nerve. If pain subsides after inferior alveolar nerve block it is suggestive of mandibular nerve involvement.
- Inject the anterior, middle, and posterior superior nerve block and infraorbital nerve blocks and do an objective or subjective assessment of pain to determine involvement of maxillary or ophthalmic division of trigeminal nerve.
- If you are unable to elicit any local pathology and patient complains of sharp shooting pain on slightest provocation, prescribe carbamazepine. If pain subsides, then it's usually suggestive of trigeminal neuralgia (therapeutic diagnosis). This should not be used as a first line for investigations and diagnosis.
Common Initial Treatments
- Topical capsaicin cream over the affected area 3-4 times/day
- Carbamazepine (200 mg/day divided in 2 doses) can be prescribed as anticonvulsant medications are effective in pain management
- Antispasmodic agents
- Alcohol injection
- Surgery: gamma-knife radiosurgery (GKR), microvascular decompression (MVD)
- Glycerol injection
- Balloon compression
- Electric current
- Severing the nerve
- If patients are suspected to have trigeminal neuralgia, it is important to determine its cause. A referral to an oral medicine specialist is required. The specialist will test for the sensory and motor innervations of different nerves and may advise additional imaging like CT or MRI scan. The specialist should be able to do a complete diagnostic work up and make a treatment plan for medical or surgical procedures in consultation or combination with a medical doctor.
- Other conditions that could be ruled out by an oral medicine specialist may include:
- Atypical pain/neuralgia
- Geniculate neuralgia
- Glossopharyngeal neuralgia
- Migrainous neuralgia
- Occipital neuralgia
- Raeder's syndrome
- Postherpetic facial neuralgia
- Sphenopalatine ganglion neuralgia
- Superior laryngeal neuralgia
- Tympanic plexus neuralgia