Constant face pain in typical trigeminal neuralgia and response to γ knife radiosurgery.

Background/aims: Constant pain, especially if prominent, is sometimes considered incompatible with a diagnosis of typical idiopathic trigeminal neuralgia. This study aims to clarify the frequency of patient-reported constant pain in patients with medically intractable, typical, idiopathic trigeminal neuralgia as diagnosed with standard clinical parameters and confirmed by the response to a modified McGill questionnaire, a 'hold-still' test that eliminated triggers and the response to Gamma Knife radiosurgery.

Method: Forty consecutive patients with typical trigeminal neuralgia were given questionnaires prior to Gamma Knife radiosurgery. Those with constant pain were further tested by being advised to hold completely still for up to 3 min. Final pain relief was evaluated after Gamma Knife radiosurgery.

Results: Twenty of forty patients indicated on a questionnaire that they had constant face pain. Pain decreased on the 'hold-still' test on all 12 patients who were tested. Following Gamma Knife radiosurgery, there was no significant difference in pain relief in those without or with constant pain.

Conclusion: Patients with typical idiopathic trigeminal neuralgia frequently report that 50% or more of their pain is constant. This constant pain is markedly decreased if the patient holds completely still for a few minutes and does not affect the outcome of Gamma Knife radiosurgery.