Long-term high frequency transcutaneous electrical nerve stimulation (hi-TNS) in chronic pain. Clinical response and effects on CSF-endorphins, monoamine metabolites, substance P-like immunoreactivity (SPLI) and pain measures.
Eighteen patients with chronic pain syndromes of organic origin were treated by means of high frequency transcutaneous nerve stimulation (hi-TNS). The CSF levels of receptorassayable Fraction I and II endorphins, substance P-like immunoreactivity (SPLI), and the monoamine metabolites 5-HIAA, HVA and MOPEG were measured before and after one week of daily treatment. Furthermore, the effects on experimental pain measures were determined. The therapeutic effect was evaluated after 30 days and 3 months of treatment. Patients with low initial concentrations of endorphins in CSF, lower than those observed in healthy volunteers, tended to have the best response to hi-TNS. There were significant increases in Fraction I endorphins and SPLI in CSF, most pronounced in the patients who responded. There were no significant changes in 5-HIAA, HVA or MOPEG in CSF. However, in early responders, the serotonin metabolite 5-HIAA tended to decrease as contrasted to an increase in non-responders. The difference between the groups was statistically significant. Confirming our earlier studies, the therapy induced changes in pain measures showed a significant, positive correlation with increasing Fraction I endorphins in CSF. Our results suggest that hi-TNS induces central changes in the endorphinergic, serotonergic and possibly substance-P-ergic systems.
B G
BG
Almay
F
F
Johansson
L
L
von Knorring
T
T
Sakurada
L
L
Terenius
D000328:Adult; D000368:Aged; D002908:Chronic Disease; D004599:Electric Stimulation Therapy; D004723:Endorphins / Q000134:cerebrospinal fluid*; D005260:Female; D005500:Follow-Up Studies; D006018:Glycols / Q000134:cerebrospinal fluid*; D006719:Homovanillic Acid / Q000134:cerebrospinal fluid*; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000134:cerebrospinal fluid*; D008297:Male; D008734:Methoxyhydroxyphenylglycol / Q000134:cerebrospinal fluid*; D008875:Middle Aged; D010146:Pain / Q000134:cerebrospinal fluid; D059408:Pain Management; D010648:Phenylacetates / Q000134:cerebrospinal fluid*; D011863:Radioimmunoassay; D013373:Substance P / Q000134:cerebrospinal fluid*; D004561:Transcutaneous Electric Nerve Stimulation
D004723:Endorphins; D006018:Glycols; D010648:Phenylacetates; D013373:Substance P; D008734:Methoxyhydroxyphenylglycol; D006897:Hydroxyindoleacetic Acid; D006719:Homovanillic Acid