ACUPUNCTURE ANALGESIA: ITS ELECTROPHYSILIGICAL CORRELATES AND THE BI-DIGITAL O-RING TEST

Creation of effective technologies in the field of acupuncture analgesia requires the clinical neurophysiologic models when it could be measured and estimated objectively. Basic schemes for acupuncture analgesia were investigated by means of different clinico-electrophysiological methods including evoked somatosensory potentials of brain and registration of the nociceptive flexion reflex, in 39 volunteers. The phasic pattern in development of acupuncture analgesia was revealed. The inhibition phase developed after the 5-10 minute mechanical stimulation of appropriate acupoints and was the most significant at the 20-30 minute interval. A short facilitation phase appeared before the inhibition one in the very beginning of the session. Acupuncture analgesia was not displayed after laseropuncture (λ=632.8 nm) as well as after blocking the acupoints with local anesthetic. According to data obtained, acupuncture analgesia has certain electrographic manifestations.

However, applying these electrophysiological methods in investigations of different stimulation schemes and parameters for electroacupuncture turned out to be too difficult because there was no possibility for real-time measurements. In this direction, a special interest represented the Bi-Digital O-Ring Test (discovered and developed by Y.Omura from 1977) as a method for monitoring the level of pain thresholds. Nowadays the details how the Bi-Digital O-Ring lest works are not completely investigated but many experiments have shown that its basic mechanism includes the muscle force changes through a brain response. The gigantocellular nucleus of reticular formation plays a central role in the realization of the Bi-Digital O-Ring Test. Recently C.Takeshige (2000) based on some experimental evidences has risen a concept of the association of the pineal gland in the Bi-Digital O-Ring Test.

In the first series, the Bi-Digital O-Ring Test was performed in comparison with the nociceptive flexion reflex expression under the influence of the mechanical stimulation of acupoints. Data were registered several times during the 30 minute session, then 30 minutes and 60 minutes after session. Principally, results obtained showed possibility to use the Bi-Digital O-Ring Test for measurement of pain sensation thresholds.

In the second series, the electroacupuncture effect on pain sensation was studied by means of the Bi-Digital O-Ring Test. The optimum stimulation frequency for the local and segmental acupoints was about 100 Hz, because it provided the most pronounced inhibition phase. For the remote acupoints, the optimum frequency was essentially lower, 10 Hz and less, which induced a more stable residual inhibition effect.

This study indicates that application of the Bi-Digital O-Ring Test allows not only to determine possibilities and physiological conditions in achievement of the purposive acupuncture analgesia but also can provide the necessary individualization of regimens and parameters for stimulation modalities.