Trigeminal Neuralgia
Content of This Page
1- Introduction
2- Causes
3- Symptoms
4- Investigations & Lab Results
5- Complications
6- Treatment
Introduction
Trigeminal Neuralgia, also called tic douloureux, is a chronic pain condition affecting the trigeminal nerve (cranial nerve V), which provides sensation to the face. It is characterized by sudden, severe, brief, and recurrent episodes of electric shock-like or stabbing facial pain. The pain typically involves one or more branches of the trigeminal nerve, most commonly the maxillary (V2) and mandibular (V3) divisions.
The attacks are often triggered by simple stimuli such as touching the face, chewing, speaking, or even a breeze. Trigeminal neuralgia usually affects middle-aged and elderly individuals and significantly impacts quality of life due to its intense pain and frequent recurrences.
Causes
1. Primary (Classic) Trigeminal Neuralgia
Caused mainly by vascular compression of the trigeminal nerve root near the brainstem
Most commonly by an artery or vein (e.g., superior cerebellar artery) pressing on the nerve
This compression leads to demyelination and abnormal nerve signaling
Usually idiopathic, without associated neurological disease
2. Secondary (Symptomatic) Trigeminal Neuralgia
Caused by other underlying neurological conditions, including:
Multiple sclerosis (MS): Demyelinating plaques affecting the trigeminal root
Tumors: Such as cerebellopontine angle tumors (e.g., acoustic neuroma, meningioma)
Arteriovenous malformations compressing the nerve
Trauma or surgical injury to the trigeminal nerve
Infections affecting the nerve (rare)
Other structural lesions like aneurysms or cysts
3. Other Risk Factors
Age (more common in people over 50)
Female gender slightly more affected than males
Symptoms
-Core Symptoms
Sudden, severe, electric shock-like or stabbing pain
Usually lasts from a few seconds up to 2 minutes per episode
Pain is typically unilateral (one side of the face)
Most commonly affects the maxillary (V2) and mandibular (V3) branches of the trigeminal nerve
Pain episodes occur in recurrent attacks or paroxysms
-Triggering Factors
Pain is often triggered by light stimuli or activities, such as:
Touching or brushing the face
Chewing or speaking
Washing the face or shaving
Exposure to wind or cold air
-Additional Features
Between attacks, the patient is usually pain-free
Severe pain may cause facial muscle spasms or grimacing (“tic douloureux”)
Over time, attacks may become more frequent and prolonged
Pain may spread to involve other branches of the trigeminal nerve
-Important Notes
There is no numbness or sensory loss in classic trigeminal neuralgia
Sensory changes suggest secondary causes and warrant further evaluation
Investigations & Lab Results
1. Clinical Diagnosis
Primarily based on characteristic history and symptoms
Physical and neurological examination usually normal between attacks
2. Imaging Studies
Magnetic Resonance Imaging (MRI) of the brain and brainstem:
Essential to rule out secondary causes such as:
Multiple sclerosis plaques
Tumors (e.g., cerebellopontine angle tumors)
Vascular compression of the trigeminal nerve root
High-resolution MRI with MR angiography may identify offending blood vessels causing nerve compression
3. Other Tests
Electrophysiological tests (e.g., trigeminal reflex testing):
Sometimes used to assess trigeminal nerve function, especially in atypical cases
Laboratory tests:
Generally not needed unless secondary causes are suspected (e.g., infection, systemic disease)
Complications
1. Chronic Pain and Disability
Recurrent, intense facial pain can become debilitating
Limits daily activities such as eating, speaking, and hygiene
Can cause social withdrawal due to fear of triggering pain
2. Psychological Impact
Increased risk of depression, anxiety, and sleep disturbances
Chronic pain can severely affect mental health and quality of life
3. Medication Side Effects
Long-term use of anticonvulsants (e.g., carbamazepine) can cause:
Dizziness, drowsiness, nausea
Blood dyscrasias (rare but serious)
Allergic reactions
Other treatments may have their own risks
4. Surgical Risks
For patients undergoing surgical treatment (e.g., microvascular decompression, rhizotomy), there is risk of:
Facial numbness or weakness
Infection
Hearing loss (rare)
Recurrence of pain
5. Secondary Causes
If underlying causes like tumors or multiple sclerosis are missed or untreated, further neurological complications can occur
Treatment
1. Medical Treatment (First-line)
Carbamazepine
Drug of choice
Effective anticonvulsant that reduces nerve excitability
Dose started low and gradually increased
Monitor for side effects (dizziness, rash, blood dyscrasias)
Oxcarbazepine
Alternative to carbamazepine with fewer side effects
Other medications (used if carbamazepine is not tolerated or ineffective):
Gabapentin
Baclofen
Lamotrigine
Phenytoin
2. Surgical Treatment
Considered if medical therapy fails, is not tolerated, or if pain recurs:
Microvascular decompression (MVD)
Surgical removal or repositioning of blood vessels compressing the trigeminal nerve
Offers long-term pain relief with preservation of nerve function
Percutaneous procedures (less invasive):
Radiofrequency rhizotomy
Glycerol injection
Balloon compression
These destroy nerve fibers to reduce pain but may cause facial numbness
Stereotactic radiosurgery (Gamma Knife)
Non-invasive focused radiation targeting the nerve root
Used for patients who are poor surgical candidates
3. Other Measures
Avoid triggers that provoke pain
Supportive care including pain counseling and psychological support