The amelioration of the suffering associated with spinal cord injury with subperception transcranial electrical stimulation

Study design: Double blind, partial crossover. Objectives: To evaluate the analgesic activity of a novel cranial electrostimulus in people with spinal cord injury (SCI). Setting: Hereward College, a residential centre that provides educational facilities for students with disabilities. Methods: Subjects with SCI experiencing chronic pain were randomly assigned into two groups, one of which received sham and the other transcranial electrostimulation treatment (TCET) on two occasions daily for four successive days. After a 'wash-out' period of 8 weeks all subjects returned and received the identical stimulus that the treated cohort received on the first arm of the study. Results: Pain measurements applied before and, after each session indicated that the pain decreased in the treated group to 51% of that reported at the commencement of treatment; reported pain intensity did not decrease significantly in the sham treated subjects. The same (sham) subject group reported experiencing 59% of the pain at the end of the second arm of the study (TCET) as on the first arm (sham). No significant differences were determined between the mood of all subjects estimated before and after each sham or TCET treatment session. The reported analgesic, and combined antidepressant and anxiolytic drug use in subjects receiving TCET on the second arm of the study, was 46% and 53% respectively of the average pre-study drug use. No similar decrease in the use of the drugs was noted in the same subjects after sham treatment on the first arm of the study. Salivary cortisol determinations made prior to and after each sham and treatment session implicated this corticoid in the pain-relieving mode of action of the treatment, but could not be associated with any changes in mood. Subjects receiving TCET had significantly higher urinary 3-methoxy-4-hydroxy-phenylglycol (MHPG) output after the TCET treatment period than sham stimulation, implicating increased central noradrenaline (NA) metabolism in the observed effects. Conclusion: The subjects reported less pain during, and immediately after receiving this transcranial treatment, although they were using less medication than when receiving sham treatment.