Could an elderly female patient with a history of root canal (dental procedure) about a year ago, now experiencing severe and stabbing pain in her right cheek radiating up to her eye, be diagnosed with trigeminal neuralgia?

Could This Be Trigeminal Neuralgia?

This presentation is unlikely to be classical trigeminal neuralgia and warrants urgent evaluation for alternative diagnoses, particularly giant cell arteritis given the patient's age and continuous severe pain pattern. 1, 2, 3

Why This Doesn't Fit Classical Trigeminal Neuralgia

The pain description raises several red flags that argue against typical trigeminal neuralgia:

• Classical trigeminal neuralgia is characterized by paroxysmal attacks lasting only seconds to minutes with mandatory refractory (pain-free) periods between attacks—not continuous pain. 1, 2, 4 The diagnosis is made on history alone, requiring sudden, unilateral, severe, brief stabbing episodes triggered by innocuous stimuli like light touch, washing, cold wind, eating, or brushing teeth. 4, 5

• The pain quality described as "severe and stabbing" extending continuously from cheek to eye does not match the electric shock-like, lancinating attacks with pain-free intervals that define this condition. 1, 4 If the patient can describe continuous pain or trigger attacks repeatedly without pain-free intervals, alternative diagnoses must be considered. 2

• The V2 (maxillary) and V3 (mandibular) branches are most commonly affected in trigeminal neuralgia, but the continuous nature extending to the eye suggests a different pathology. 4

Critical Differential Diagnoses to Exclude Urgently

Giant Cell Arteritis (Temporal Arteritis)

In an elderly female patient, giant cell arteritis demands immediate consideration and treatment to prevent irreversible vision loss. 3

• Look for: continuous, dull, aching pain in the temporal region and jaw, pain aggravated by chewing (jaw claudication), scalp tenderness, visual disturbances, malaise, fever, myalgia, elevated ESR/CRP, and absent or diminished temporal pulse. 1, 3

• Start high-dose corticosteroids immediately upon suspicion without waiting for biopsy results. 3 Obtain ESR and CRP urgently, and arrange temporal artery biopsy within 2 weeks of starting treatment. 3

Post-Traumatic Trigeminal Neuropathic Pain

Given the root canal history one year ago, this is a strong consideration:

• Post-traumatic trigeminal pain develops within 3-6 months of dental procedures or trauma and presents as continuous burning, tingling pain—not paroxysmal attacks. 1, 2 The timing (one year post-procedure) makes this less likely but still possible. 1

• Examination may reveal allodynia or other sensory changes in the affected distribution. 1 Qualitative sensory testing can help confirm the diagnosis. 1

Atypical Odontalgia (Persistent Dentoalveolar Pain)

• Presents as continuous aching, dull, throbbing pain localized to tooth or tooth-bearing area with mild to moderate severity. 1

• Requires intraoral X-rays to exclude ongoing dental pathology. 1

Type 2 Trigeminal Neuralgia

• If the patient experiences prolonged continuous pain between characteristic sharp shooting attacks, Type 2 trigeminal neuralgia becomes possible. 2 This variant may originate from more central mechanisms rather than peripheral neurovascular compression. 2

Diagnostic Workup Required

Obtain MRI with high-resolution thin-cut sequences through the trigeminal nerve course in all suspected cases to identify neurovascular compression and exclude secondary causes such as multiple sclerosis, tumors, or other structural lesions. 2, 4 Use 3D heavily T2-weighted sequences combined with MRA, which show 83-100% congruence with surgical findings. 4

The presence of continuous pain mandates MRI evaluation to rule out secondary causes. 2

Check for:

• Sensory deficits in trigeminal distribution (requires urgent imaging if present) 2
• Motor weakness in muscles of mastication (rare, suggests secondary cause) 4
• Signs of multiple sclerosis if secondary trigeminal neuralgia is suspected 4

If Trigeminal Neuralgia Is Confirmed

Carbamazepine is the gold standard first-line treatment, with oxcarbazepine being equally effective with fewer side effects. 4, 6, 5, 7 The FDA specifically indicates carbamazepine for the treatment of pain associated with true trigeminal neuralgia. 6

Second-line options include lamotrigine, baclofen, gabapentin combined with ropivacaine, and pregabalin. 4, 8

Obtain neurosurgical consultation early when medications become ineffective or intolerable. 4 Microvascular decompression is the preferred surgical option for patients with documented neurovascular compression on MRI, offering 70% pain-free rates at 10 years. 4

Common Pitfalls to Avoid

• Do not assume trigeminal neuralgia based solely on facial pain location—the temporal pattern (paroxysmal vs. continuous) is the critical distinguishing feature. 1, 2, 4

• Do not delay evaluation for giant cell arteritis in elderly patients with atypical facial pain—vision loss can occur rapidly and irreversibly. 3

• Do not use carbamazepine as a simple analgesic for trivial aches or pains—it is specifically indicated for true trigeminal neuralgia. 6