Acupuncture for Inflammatory Pain and Central Sensitization - A Pilot Study

Acupuncture is used extensively by patients worldwide for a variety of illnesses. While
research is beginning to show effectiveness in clinical pain, the mechanisms underlying how
these effects are evoked are poorly understood. Experimental models in healthy human
volunteers can more closely control the variables of acupuncture needling and begin to
separate out the relative contribution of specific components of needling and needle
stimulation. By examining acupuncture's effects on experimental inflammatory models with
well-characterized physiologic mechanisms, hypotheses can begin to be generated regarding
how acupuncture produces its clinical effects. We propose to establish a model which could
be used as a template to examine the individual components contributing to acupuncture's
clinical effects on inflammation and pain. We hypothesize that acupuncture will have
analgesic and anti-inflammatory effects on a ultraviolet B induced cutaneous lesion as well
as a model of heat pain testing which activates central sensitization.

Twenty healthy human volunteers will participate in a crossover study with active
acupuncture and sham acupuncture interventions. They will be tested for their minimal
erythemal dose (MED) to ultraviolet B exposure. An experimental lesion at 3x MED will be
administered on the lower leg. Background information will be collected which could affect
individuals' sensitivity to pain such as anxiety and depression, as well as their
expectations regarding acupuncture treatment.

The following day they will return for the first experimental day. A measurement with Laser
Doppler will quantify the inflammation in the ultraviolet B lesion. Heat pain testing will
be performed using a computer controlled thermode both on and off the ultraviolet B lesion.
On-lesion testing will be for heat pain threshold. Off-lesion testing will examine temporal
summation of heat pain.

Next, a licensed acupuncturist will perform either true electroacupuncture or sham
electroacupuncture in the region adjacent to the ultraviolet B lesion. Participants are
blinded to the intervention, as is the examiner collecting data. Afterwards, Laser Doppler
and heat pain testing will be repeated. The difference between pre-acupuncture and
post-acupuncture measurements will represent the acupuncture -induced analgesic and
anti-inflammatory effects.

Participants will return for another ultraviolet B exposure adjacent to the first, and will
receive whichever sham or true acupuncture intervention was not performed on the first study
day.