OBJECTIVE AND CLINICAL IMPORTANCE: We present a case of trigeminal neuralgia resulting from infarction of the root entry zone of the trigeminal nerve. This is the first reported case of an unusual cause of trigeminal neuralgia.
Clinical presentation: A 71-year-old man presented with severe lancinating pain in the left V1 and V2 distributions. Magnetic resonance imaging of the brain demonstrated a small wedge-shaped infarct at the root entry zone of the left trigeminal nerve in the pons.
Intervention: Medical management with carbamazepine was initially successful, but the patient later developed refractory pain and was unable to tolerate side effects of the medication. The patient underwent subsequent percutaneous glycerol rhizotomy, which resulted in complete resolution of his pain.
Conclusion: Infarction of the root entry zone may produce typical symptoms of trigeminal neuralgia similar to a multiple sclerosis plaque at the root entry zone. Treatment of trigeminal neuralgia must consider the underlying cause. Glycerol rhizotomy may provide relief of pain for patients in whom there is no evidence of vascular compression.