What is the diagnosis and treatment for a patient experiencing unilateral facial pain, specifically pain on the left side of the face, left eye pain with limited mobility and blindness, left nostril burning sensation, left jaw tightness, left ear pain, fullness and hearing loss, and left throat pain, with symptoms triggered by cold or sore throat?

Diagnosis: Trigeminal Autonomic Cephalgia (SUNCT/SUNA)

This patient's constellation of unilateral facial pain with eye pain, nasal burning, ear fullness, and throat pain—all triggered by upper respiratory infections—is most consistent with a trigeminal autonomic cephalgia, specifically SUNCT/SUNA syndrome, not classical trigeminal neuralgia. 1

Critical Diagnostic Features

The key distinguishing features pointing to SUNCT/SUNA rather than other facial pain syndromes include:

• Autonomic features: The combination of eye pain, nasal burning sensation, ear fullness, and hearing loss represents cranial autonomic symptoms (tearing, nasal blockage/rhinorrhea, ear fullness) that are pathognomonic for trigeminal autonomic cephalgias 1

• Unilateral distribution: Pain strictly confined to the left side involving multiple trigeminal divisions (ophthalmic, maxillary, mandibular) plus glossopharyngeal territory (throat) 1

• Trigger pattern: Upper respiratory infections and sore throat as triggers distinguish this from classical trigeminal neuralgia, which is typically triggered by light touch, washing, or eating 1

• Blindness concern: The presence of visual impairment requires urgent evaluation to exclude giant cell arteritis if the patient is over 50 years old, as this can cause irreversible blindness without immediate treatment with systemic steroids 1

Differential Diagnosis Considerations

Rule Out Giant Cell Arteritis First (Age-Dependent)

If this patient is over 50 years old, giant cell arteritis MUST be excluded immediately before pursuing other diagnoses. 1

• Obtain ESR and C-reactive protein urgently 1
• Arrange temporal artery biopsy within 2 weeks 1
• Start high-dose systemic steroids immediately if clinical suspicion is high, even before biopsy confirmation 1

Why Not Classical Trigeminal Neuralgia?

Classical trigeminal neuralgia is characterized by paroxysmal attacks lasting only seconds to minutes with mandatory refractory periods between attacks—not continuous pain 2. This patient's description of continuous symptoms with multiple autonomic features excludes classical trigeminal neuralgia 2.

Why Not Glossopharyngeal Neuralgia?

While glossopharyngeal neuralgia can cause deep ear pain and throat pain, it typically presents as sharp, shooting, electric shock-like pain triggered by swallowing or coughing, and may be associated with syncope 1. The presence of eye pain, nasal symptoms, and jaw tightness extends beyond the glossopharyngeal distribution 1.

Why SUNCT/SUNA Fits Best

SUNCT/SUNA syndromes present with:

• Rapid attacks lasting seconds to several minutes 1
• Up to 200 attacks daily with no refractory period between attacks 1
• Prominent autonomic features including tearing, conjunctival injection, rhinorrhea, nasal blockage, facial redness, and ear fullness 1
• Pain mainly in first and second trigeminal divisions 1

Mandatory Investigations

Neuroimaging

Obtain MRI with contrast including pituitary fossa views immediately. 1, 2

The MRI serves to:

• Exclude secondary causes (multiple sclerosis, tumors, structural lesions) 2
• Evaluate for neurovascular compression 2
• Include pituitary fossa views specifically when SUNCT/SUNA is suspected 1

Laboratory Studies (If Age >50)

• ESR and C-reactive protein to exclude giant cell arteritis 1

Treatment Algorithm

First-Line Medical Management

Start lamotrigine as the preventive drug of choice for SUNCT/SUNA. 1, 3, 4

• Lamotrigine 100-300 mg/day is the first-line preventive treatment 3, 4
• This is the only treatment with consistent evidence for SUNCT/SUNA, though no RCTs exist 1

Alternative Medical Options

If lamotrigine is ineffective or not tolerated:

• Gabapentin 800-2700 mg/day 3
• Topiramate 50-300 mg/day 3
• Carbamazepine 200-1600 mg/day (though less effective than in classical trigeminal neuralgia) 3

Acute Exacerbations

For severe exacerbations, consider:

• Short course of intravenous lidocaine 1-4 mg/kg/hour to reduce attack frequency 3

Surgical Considerations

Surgery has poorer outcomes in SUNCT/SUNA compared to classical trigeminal neuralgia because the underlying pathophysiology differs from simple neurovascular compression. 1

• Microvascular decompression can be attempted but has lower success rates 1
• The etiology may be more central than peripheral, accounting for poorer surgical outcomes 1

Critical Pitfalls to Avoid

1. Do not confuse with trigeminal neuralgia: The presence of autonomic features and continuous pain excludes classical trigeminal neuralgia 2

2. Do not miss giant cell arteritis: In patients over 50 with temporal pain and visual symptoms, delay in treatment can result in permanent blindness 1

3. Do not use carbamazepine as first-line: While carbamazepine is gold standard for trigeminal neuralgia, lamotrigine is specifically indicated for SUNCT/SUNA 1, 3, 4

4. Do not expect surgical cure: Set realistic expectations that surgical interventions have limited efficacy in trigeminal autonomic cephalgias compared to classical trigeminal neuralgia 1

5. Do not overlook the trigger pattern: Upper respiratory infections as triggers suggest a different pathophysiology than the light-touch triggers of classical trigeminal neuralgia 1