International Handbook of Clinical Hypnosis - E-Lib FK UWKS

70 INTERNATIONAL HANDBOOK OF CLINICAL HYPNOSIS
completely eliminate all perception of pain or distress during cold pressor pain
training with hypnotic analgesia Crawford, 1995b; Crawford et al., 1996, 1997; in
preparation); and b) adults with enduring chronic low back pain who, as a group,
were able to reduce their pain by 90% in cold pressor training with hypnotic
analgesia Crawford, Knebel, Kaplan et al., 1998). After training with cold pressor
pain, subjects returned the next week for the SEP study.Blocks of 30 electrical
stimuli were delivered to the left middle ®nger, the intensity of which was titrated
to each subject to be rated as strongly painful but bearable 7±8 on 0±10 point
scale).During hypnosis, an A-B-A design was employed: a) normally attend to
stimuli; b) hypnotically suggested analgesia; and c) normally attend to stimuli.
Among the college students, highs had a signi®cantly higher P70 in the right
anterior frontal Fp1) and parietal regions during attend, yet during hypnotic
analgesia there was a dramatic reduction of P70 only at the right anterior frontal
region.During hypnotic analgesia, only highs showed signi®cant reductions of
P200 in central and parietal regions & of P300 in the central region.The N140 and
N250, both possibly re¯ective of greater inhibitory processing, were enhanced
during hypnotic analgesia.
The participants with chronic low back pain showed signi®cant reductions in
P200 bilateral midfrontal and central and left parietal regions) and P300 right
midfrontal and central regions) during hypnotic analgesia.Furthermore, hypothesized
inhibitory processing was evidenced by enhanced N140 in the anterior frontal
region and by a pre-stimulus positive-ongoing contingent cortical potential at left
anterior frontal Fp1) region only during hypnotic analgesia.These ®ndings suggest
that two pain processes are affected by hypnotic analgesia: one dealing with the
allocation of attention to pain frontal attention system) and one dealing with the
perception of the intensity of pain frontal attention system working via connections
with the thalamus and possibly other cortical and subcortical regions).
Furthermore, of particular relevance to clinicians, we documented the development
of self-ef®cacy through the successful transfer of the newly learned skills of
experimental pain reduction to the reduction of the participant's own chronic pain
Crawford, Knebel et al., 1998). Over three experimental sessions, they reported
signi®cant reductions of experienced chronic pain, increased psychological wellbeing
and increased sleep quality.We argue that `the development of ``neurosignatures
of pain'' can in¯uence subsequent pain experiences Coderre, Katz, Vaccarino
& Melzack, 1993; Melzack, 1993) and may be expanded in size and easily
reactivated Flor & Birbaumer, 1994; Melzack, 1991, 1993).Therefore, hypnosis
and other psychological interventions need to be introduced early as adjuncts in
medical treatments for onset-pain before the development of chronic pain' p.92).
In a patient undergoing dental surgery with hypnosis as the sole anesthetic,
Chen, Dworkin and Bloomquist 1981) found total EEG power decreased with a
greater diminution in the left hemisphere in alpha and theta EEG bands.Karlin,
Morgan and Goldstein 1980) reported hemispheric shifts in total EEG power
during hypnotic analgesia to cold pressor pain that were interpreted as greater