Diagnostic value of some less frequently considered blink reflex parameters in idiopathic trigeminal neuralgia.

AIM OF THE STUDY: We have done a study investigating the value of some less frequently considered Blink reflex parameters for establishing the diagnosis of idiopathic trigeminal neuralgia.

PATIENTS: The study was done on 50 patients suffering from idiopathic trigeminal neuralgia, diagnosed according to the guidelines of the International Classification of Headache Disorders, with no other apparent illness.

METHODS

We have stimulated the supraorbital nerve at the forehead (foramen n. supraorbitalis) and recorded the reflex response on both mm. orbiculares oculi. Incidence of following findings was determined: (1) occurrence of ipsilateral R3 component, (2) prolonged duration (>25 ms) of R2 when stimulating the affected side and (3) occurrence of R1 component during the stimulation of contralateral supraorbital nerve. We have compared these findings to those of 50 healthy subjects from the control group (Chi-square, p < 0.05). Sensitivity, specificity and diagnostic value for individual parameters were determined.

RESULTS AND

CONCLUSION

All three parameters tested proved to have a significantly higher incidence in the group of subjects. The occurrence of R3 component on the affected side showed the highest diagnostic value.

SIGNIFICANCE: We believe these findings could electrophysiologically reinforce the clinically established diagnosis of idiopathic trigeminal neuralgia.