Objective:

To describe a reproducible remission of Trigeminal neuralgia (TN)  temporally associated with memantine therapy.

Background:

Trigeminal neuralgia (TN) presents with recurrent, paroxysmal, shock-like unilateral facial pain. First-line therapies are carbamazepine and oxcarbazepine; alternatives include gabapentin, lamotrigine, and baclofen, with procedural or surgical options for refractory disease. Treatment is often limited by adverse effects or contraindications, underscoring the need for additional, well-tolerated options. Memantine, an NMDA receptor antagonist approved for Alzheimer’s disease, has been explored in other pain conditions but evidence in TN is sparse.

Design/Methods:

A 62-year-old patient with hypertension developed paroxysmal, unilateral left facial pain consistent with ICHD-3 (International Classification of Headache Disorders) criteria for TN. Brain MRI revealed no structural, demyelinating, or other secondary cause. Memantine 10 mg daily was initiated for cognitive concerns. Within two weeks, the patient reported complete resolution of TN attacks. During a planned two-week interruption, pain recurred within 48 hours of discontinuation and remitted within 48 hours of re-initiation, suggesting a discontinuation and rechallenge effect.

Results:

The patient has remained pain-free on continued memantine 10 mg daily without reported adverse effects.

Conclusions:

While carbamazepine/oxcarbazepine remain first-line for TN and should be prioritized when effective and tolerated, this single case suggests memantine may have therapeutic potential in select patients, particularly when standard agents are contraindicated or poorly tolerated. The rapid response and reproducibility with withdrawal and re-exposure strengthen the temporal association but do not establish causality. Prospective studies are needed to evaluate efficacy, safety, dose–response, and patient selection, and any use should be considered off-label within shared decision-making.