Hi Sarah, I just looked up the treatment for your condition, & this is what it said for using anti-convulsants for trigeminal neuralgia:
To treat trigeminal neuralgia, your doctor usually will prescribe medications to lessen or block the pain signals sent to your brain.
Anticonvulsants. Doctors usually prescribe carbamazepine (Tegretol, Carbatrol, others) for trigeminal neuralgia, and it's been shown to be effective in treating the condition. Other anticonvulsant drugs that may be used to treat trigeminal neuralgia include oxcarbazepine (Trileptal). Other drugs, including clonazepam (Klonopin) and gabapentin (Neurontin, Gralise, others), also may be used.
If the anticonvulsant you're using begins to lose effectiveness, your doctor may increase the dose or switch to another type. Side effects of anticonvulsants may include dizziness, confusion, drowsiness, double vision and nausea. Also, carbamazepine can trigger a serious drug reaction in some people, mainly those of Asian descent, so genetic testing may be recommended before you start carbamazepine.
Antispasmodic agents. Muscle-relaxing agents such as baclofen (Gablofen, Lioresal) may be used alone or in combination with carbamazepine. Side effects may include confusion, nausea and drowsiness.
Since Lamictal is a anti-convulsant, I would tend to think this is why he did prescribe it for you. Mary