To determine the diagnostic approach for trigeminal neuropathy and identify high- and low-yield studies to improve cost-effectiveness.

We conducted a retrospective chart review of patients with non-traumatic, non-iatrogenic TSN. Demographic data, clinical characteristics, diagnostic studies ordered, etiology, and treatment plans were recorded. These data were analyzed using descriptive statistics to determine which diagnostic studies were most useful in identification of a final diagnosis.

518 patients were identified for inclusion. Of the patients currently reviewed, participant ages ranged from 20-85 years (median 55), with 63.2% being female. The final etiology was idiopathic in 56.7% of cases, neoplastic in 21.1%, and due to specific connective tissue diseases in 17.3%. In those cases in which a specific etiology was identified, this identification was made by MRI in 45.6% of cases, by history or clinical progression of a pre-existing connective tissue disorder in 21.1% of cases, by abnormal connective tissue disease cascades combined with clinical confirmation by a consulted rheumatologist in 18.9% of cases, and by abnormal connective tissue disease cascades evaluated by neurology alone in 7.8% of cases. EMG was performed in 51.4% of cases, and lumbar puncture was performed in 34.1%, but neither identified a treatable etiology in any case.