Classification of facial pain: a 13-year population-based study

Introduction: Accurate diagnosis and classification of facial pain is critical for assigning surgical treatment, avoiding misdirected interventions and studying outcomes. We conducted a population-based longitudinal study of patients with facial pain and compared diagnostic classification systems. Methods: Medical records for all Manitobans presenting to our centre with a primary complaint of facial pain from 2001 to 2013 were reviewed. We then applied diagnostic criteria from the International Classification of Headache Disorders (IHS-3), the International Association for the Study of Pain (IASP) and Burchiel’s system for comparisons. Results: There were 534 patients with facial pain (3.4/100,000/year) and two-thirds of these had conditions potentially amenable to neurosurgical interventions. Our most common diagnoses were typical trigeminal neuralgia(50%), atypical trigeminal neuralgia(7%), idiopathic trigeminal neuropathy(7%), idiopathic facial pain(11%); average ages were 65±14(22-99), 60±18(32-86), 55±16(28-83) and 48±12(28-82) with a female proportion of 55%, 59%, 65% and 80%, respectively. Other classification systems included no criteria for idiopathic trigeminal neuropathy. The classifications of “trigeminal neuralgia type-1 and type-2” did not differentiate between surgical and non-surgical candidiates. Conclusion: Published classification systems of facial pain have differing criteria for diagnosis of trigeminal neuralgia and none defines a large group with idiopathic trigeminal neuropathy. This may lead to considerable variability in determinations of potential surgical candidates and comparing outcomes of treatment.