Research in the Application of Nd-YAG Laser to Trigeminal Neuralgia Treatment

-Examination by Somatosensory Evoked Potentials-

Abstract

The treatment of trigeminal neuralgia, which is represented by acute pains of repetitive and idiopathetio nature, uses mostly an alcohol block of the peripheral nerves. The average effective period of an alcohol block is about 15 months, and in most cases acute pains recurred with sensory recovery. To establish a more effective nerve block, an application of the Nd YAG laser was devised that utilizes this laser's high transmissivity through tissues.
A delicate laser probe was developed for the experiment, in which a laser beam is directed to the peripheral nerves through a small incised opening in the oral cavity. The purpose of the experiment was to objectively determine the effect of this new blocking method. The somatosensory evoked potential (SEP), a widely used index of sensation against stimulus, was measured under laser blocking and compared with that of an alcohol nerve block.
Both the P₁ and N₁ waves disappeared immediately after the laser block was applied, and the waveforms were observed with no change in time that are similar to those seen after nerves are severed. The average effective period in 12 clinical treatments of trigeminal neuralgia using the new laser block was 23 months, and the longest was 56 months until 1987, June.
The new Nd-AG laser block is clearly effective in treatment of trigeminal neuralgia.