Trigeminal Neuralgia and other Cranial Neuralgias Ottawa Program

Yes. Trigeminal neuralgia and migraine are distinct neurologic conditions with different causes, symptoms, and treatments.

• Trigeminal neuralgia causes brief, electric-shock–like facial pain triggered by touch or movement and is due to dysfunction of the trigeminal nerve.

• Migraine causes longer-lasting head pain with sensitivity to light, sound, or nausea and involves altered brain pain processing.

Because treatments differ, accurate diagnosis is essential.

The trigeminal nerve has three branches:

• V1 (ophthalmic) – forehead, eye, scalp

• V2 (maxillary) – cheek, upper jaw, upper teeth

• V3 (mandibular) – lower jaw, chin, lower teeth

Trigeminal neuralgia usually involves one or more of these branches and is almost always side-locked.

Classical trigeminal neuralgia

• Most common form

• Usually due to vascular compression of the trigeminal nerve

• Often responds well to medication and surgery

Idiopathic trigeminal neuralgia

• No clear cause identified despite appropriate imaging

Secondary trigeminal neuralgia

• Caused by an underlying condition such as:

  • Multiple sclerosis

  • Tumor

  • Structural lesion

Several conditions can resemble trigeminal neuralgia and must be distinguished carefully.

Persistent idiopathic facial pain (PIFP)

• Constant or near-constant facial pain

• Poorly localized

• Not shock-like

• Lacks clear triggers

PIFP is a common diagnostic pitfall and does not respond to trigeminal neuralgia–specific treatments.

Other mimics

• Dental disease

• Temporomandibular joint (TMJ) disorders

• Sinus disease

• Post-herpetic neuralgia

• Migraine-related facial pain

Careful history is essential to avoid misdiagnosis.

MRI Brain

All patients with suspected trigeminal neuralgia should undergo MRI of the brain, including:

• High-resolution imaging of the posterior fossa

• Imaging through the sella and trigeminal nerve pathways

MRI helps:

• Identify vascular compression

• Exclude secondary causes such as tumors or demyelination

Carbamazepine is a medication that stabilizes overactive nerve signaling.

It is considered a first-line treatment for trigeminal neuralgia and is also used for other nerve-related pain conditions. 

Carbamazepine works by:

• Reducing abnormal electrical firing in nerves

• Stabilizing nerve membranes

• Preventing sudden pain signals that cause electric-shock–like attacks

It does not work as a general painkiller and is not used for typical headache pain.

Carbamazepine is:

• Taken by mouth

• Usually started at a low dose

• Gradually increased until pain is controlled or side effects limit dosing

Slow dose increases help improve tolerability.

Typical dosing approach

Dosing is individualized, but a common approach includes:

• Starting with a low dose once or twice daily

• Gradual increases every few days to weeks

• Dividing doses across the day to reduce side effects

The goal is the lowest dose that effectively controls pain.

We will guide dose adjustments carefully.

How quickly does carbamazepine work?

• Many patients notice improvement within days

• In trigeminal neuralgia, response is often rapid

• Lack of response may prompt dose adjustment or reconsideration of diagnosis

Side effects are common, especially early or at higher doses.

Common side effects include:

• Drowsiness or fatigue

• Dizziness or unsteadiness

• Nausea

• Blurred or double vision

These often improve with:

• Slower dose increases

• Dose adjustment

• Time

Less common but important side effects

Less common side effects include:

• Low sodium levels in the blood

• Allergic skin reactions

• Liver enzyme changes

• Blood count abnormalities

Because of this, blood tests are usually done:

• Before starting

• Periodically during treatment

Contact your care team or seek urgent care if you develop:

• Rash (especially widespread or blistering)

• Fever with rash

• Severe fatigue or confusion

• New bruising or bleeding

• Signs of allergic reaction

These are uncommon but important to evaluate promptly.

Occipital nerve blocks are commonly used in occipital neuralgia.

They involve:

• Injection of local anesthetic (sometimes with steroid)

• Targeting the occipital nerves

• Both diagnostic and therapeutic benefit

Nerve blocks may:

• Provide temporary or longstanding relief

• Help confirm the diagnosis

• Be repeated as part of ongoing management

Other treatment may include:

• Medications for neuropathic pain

• Physical therapy or posture-focused interventions

• Avoidance of aggravating factors

An occipital nerve block involves injecting a small amount of local anesthetic, sometimes combined with a corticosteroid, around the occipital nerves at the back of the head.

These nerves transmit pain signals from the scalp and upper neck. Temporarily calming them can reduce headache pain and sensitivity.

Occipital nerve blocks are an effective treatment for occipital neuralgia, and can be an effective adjunct to some patients with other headache disorders (e.g., migraine, cluster headache).

Occipital nerve blocks involve a small injection in the greater (and possibly lesser) occipital nerves in the back of the scalp. The injections are superficial and resemble the injections you may have experienced when going to the dentist.

Most people feel brief stinging, and no sedation is required. The injections themselves do not cause sedation, and you are able to drive afterwards.

• Some people notice improvement within minutes to hours

• For others, benefit develops over 1–3 days

• Relief may last days to weeks, and sometimes months

Response varies between individuals.