WHAT'S
NEW -- March 2001
This
month's "What's New" section abstracts are from new research
studies presented at the 18th Annual Scientific Meeting of
the American Pain Society Meeting, which took place in Fort
Lauderdale, Florida, October 21-24, 1999. More than 800 scientific
abstracts were presented at this meeting of international
pain specialists. We have chosen just a few that we found
interesting and potentially useful to patients and pain health
care providers.
Fibromyalgia
and Chronic Fatigue Syndrome Share Similar Symptoms and Perhaps
An Underlying Cause
Twenty
(20) patients with Fibromyalgia (F), 20 patients with Chronic
Fatigue Syndrome (CFS), and 20 healthy normal people were
given a series of questionnaires assessing pain and hypervigilance
(the biological tendency to pay attention to different stimulation)
and also were examined for the presence of fibromyalgia tender
points. The results demonstrated many similarities among the
F and CFS patients:
 |
Similar
levels of pain; |
|
Many
CFS patients had multiple fibromyalgia tender points;
and |
|
Similar
levels of hypervigilance to all noxious (unpleasant) stimuli.
|
Thus,
these researchers concluded that patients with F and CFS share
many symptoms and signs suggesting a similar underlying pathophysiological
mechanism.
Gillespie JM, Rollman GB, and McDermid AJ. Are Fibromyalgia
and Chronic Fatigue Syndrome Related? A Comparision of Tender
Points and Perceptual Sensitivity. University of Western Ontario.
Editor's
Note: This study addresses two important issues in clinical
care and research: (1) Are there similarities between Fibromyalgia
and Chronic Fatigue Syndrome? The results of this small study
suggest that indeed these distinct clinical syndromes both
have similar levels of pain and tender points found on physical
examination. (2) What are the underlying mechanisms responsible
for these poorly understood disorders? The results of this
study (and several other studies) point to a central nervous
system abnormality. Specifically, a "hypervigilance disorder,"
that is, the patient's brain magnifies all sensory stimulation,
whether from external/environmental sources or from internal/bodily
sources. Thus, whereas a slight neck ache to a normal person
can be ignored, the exact same sensation to a fibromyalgia
patient will be magnified by his/her brain forcing them to
pay attention to it.
 
Attention
to Pain Alters Brain Region
This
study evaluated the changes in the activity of the brain region
"periaqueductal gray (PAG)" in normal volunteers associated
with a painful heat stimulus. The painful heat was applied
during two different study conditions: (1) when paying attention
to the painful stimulus, and (2) when asked to pay attention
to a distracting visual stimulus, and not the pain. The PAG
is at the base of the brain and has been known to be involved
in pain modulation, i.e., the natural ability to affect how
much pain is perceived. The results showed that when the subjects
were asked not to pay attention to the
pain that both their pain scores were lowered and the PAG
was activated.
Tracey I, Matthews PM, Ploghaus A, Gati JS, Robarts JP, Menon
RS. High Resolution Functional MRI Detects Modulation of the
Periaqueductal Gray Activation by Attention. Oxford University.
Editor's
Note: This fascinating study has demonstrated that distraction
does lower the perceived intensity of pain by altering the
brain. A similar study was also presented this summer at the
World Congress of Pain with the same conclusion. Both patients
and pain clinicians need to be open to psychological interventions,
such as distraction, and prescribe them more often. In addition,
it makes biological sense that some chronic pain disorders
may be due to a malfunctioning of the natural pain modulating
system.
Hypnosis Can Be Effective in Reducing
Spinal Cord Injury Pain
Spinal
cord injury pain (SCI) is a severe disabling pain that is
most often refractory to most pain medications. This study
evaluated the use of hypnosis on 22 patients with SCI. After
five hypnotic sessions, 19 (86%) of patients reported decreased
pain intensity and pain unpleasantness. These decreases occurred
both during the hypnotic state and also upon awakening.
Jensen MP, Brown MZ, Barber J, Williams-Avery RM, Flores L.
The Effect of Hypnotic Suggestion on Spinal Cord Injury Pain.
University of Washington, Seattle.
Editor's
Note: This interesting study reports pain relief following
hypnosis treatment in a group of patients with a typically
severe and refractory pain syndrome. If indeed such a good
response can be maintained following the actual hypnosis,
then hypnosis therapy can be entertained for this group
of patients. It is important to realize that this group of
clinical researchers is expert in pain medicine and thus translating
their results to any person who can perform hypnosis cannot
be made. It is recommended if hypnosis therapy is to be pursued
that the practitioner be expert in pain medicine as well as
hypnosis. Future research is being pursued by this group.
Tizanidine May Be Helpful in Certain Chronic Headache Conditions
This
open-label study (not placebo controlled) evaluated 150 headache
patients treated with a titrating dose of tizanidine (Zanaflex®).
Diagnoses included "chronic tension-type headache (CTTH),"
"chronic daily headache (CDH)," and "mixed migraine with tension-type
headache(MMTTH)," using the International Headache Society
Criteria. The dose of tizanidine was titrated for one month
and continued for an average of 120 days. The average mean
dose was 26mg per day. There was a clinically meaningful reduction
in headaches reported:
|
Average
headache severity was reduced by 74% (using a 0-10 scale).
|
|
Average
headache frequency was reduced by 72.5%. |
|
Sleep
patterns improved in "virtually all patients," even non-responders.
|
|
Only
28 (19%) had no headache response or discontinued the
drug due to side effects. |
Krusz
JC, Belanger J. Anodyne Pain Care. Tizanidine: An Effective
Novel Agent for Treatment of Chronic Headaches.
Editor's
Note: This uncontrolled study reported that a dramatic reduction
in headache frequency and intensity in this group of usually
hard-to-treat patients. Tizanidine is currently FDA approved
for the treatment of muscle spasticity. It has a unique mechanism
of action via alpha-2 adrenergic, that typically is not thought
of as being involved in headache. Earlier studies from Europe,
one of which is placebo-controlled, have shown benefit for
tizanidine for tension-type headache. Surprising in this study
is that vast majority of patients tolerated an average dose
of 26mg; our experience is that many patients do not tolerate
the sedative effects of this drug. However, this study and
prior studies do suggest a potential role for tizanidine in
treating non-migraneous headaches. Placebo-controlled trials
need to be performed to confirm these findings.
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