Pearls & Oy-sters: Bilateral Neuropathic Facial Pain With Autonomic Features and Neurovascular Contact

Trigeminal neuralgia (TN) is an uncommon disorder, with an annual prevalence of 0.03%-0.3% in North America. It is typically unilateral, most commonly involving the V2 and V3 distributions and may be accompanied by mild autonomic features. We report a 35-year-old woman who developed severe right more than left-sided facial pain in the V1 and V2 divisions (upper and midface), occurring up to 100 times daily after repetitive use of cosmetic products. Following a viral upper respiratory infection, the pain progressed to bilateral symmetric V1 and V2 involvement and was associated with new bilateral autonomic symptoms, including facial swelling, tearing, and nasal congestion. As recommended in all TN cases, MRI of the head was performed to assess for secondary causes, such as multiple sclerosis, cerebellopontine angle tumors, systemic lupus erythematosus, and neurosarcoidosis. Imaging revealed neurovascular contact between the superior cerebellar artery and the bilateral trigeminal nerves, without evidence of demyelination or nerve signal abnormality. Because the nerves appeared intact, this finding was felt unlikely to explain the symptoms, but rather, to be incidental. The patient experienced significant pain relief with carbamazepine and additional improvement in autonomic symptoms with a trial of indomethacin after a postinfectious pain flare, suggesting possible overlap with trigeminal autonomic cephalalgias (TACs). This case illustrates the diagnostic challenges of an uncommon facial pain presentation, characterized by progression to mirror-symmetric bilateral V1 and V2 involvement and autonomic features. Given the overlap between TN and other facial pain syndromes, including TACs, a multifaceted treatment approach may be necessary.