As a physician specializing in the diagnosis and treatment of chronic pain,
I am often faced with the truth that pain is not simply a sensation but
an experience unique to the individual. Each person's
pain response to an acute injury or chronic condition is contingent upon a
wide array of factors that aren't only physical. Among the many reasons
that pain can be challenging to manage is that the experience of it includes
often-complicated aspects that are biological, psychological, and social.
A recently published study in the
Journal of Neurophysiology corroborates my in-clinic experience in finding that each person's
experience of pain is unique – much like a fingerprint. The study
focused on group vs. individual responses to nociceptive vs. tactile stimuli.
The methods used by the researchers in conducting the study are reasonable,
although they come with some built-in assumptions. The first assumption
is that a) pain perception correlates with nociception, and b) there exists
an objective and reproducible signature observable in gamma oscillations
(brain waves findings) that correlates with the experience of pain. I
realize this analysis is highly technical. However, in my opinion, current
concepts related to pain experience are individual and variable because
there are complex biological, psychological, and social influences that
vary from person to person and interact to result in the experience of pain.
Pain is different from nociception, as evidenced by the many studies documenting
a lack of clear and consistent correlation between the electrical signals
we can measure accurately and the experience of pain a person reports.
Simply put, the same observable brain wave patterns in two individuals
exposed to pain can result in vastly different experiences of that pain.
As such, additional information regarding clear and vital contributing
factors (biological, psychological, and social) must be considered when
interpreting the complex relationships between nociceptive/pain stimuli,
tactile stimuli, electrical activity, and the experience of pain. The
findings of this study are not surprising in that there is significant
variability from person to person (which supports what we see clinically
regarding individual variability regarding the subjective nature of pain).
Pain is defined as an unpleasant sensory and emotional experience associated
with or resembling that associated with actual or potential tissue damage.
Thus, pain is not a "sensation" but an "experience ."
As such, it is ALWAYS personal, individual, and subjective. So, it is
unsurprising that the gamma oscillations observed in the abovementioned
study vary significantly from person to person. Interestingly, the findings
are reproducible within an individual, which may have future implications
regarding objective measures of pain and objective measures to assess
pain interventions/treatments (particularly in the short term). We believe
that the "thresholds" for the experience of pain can change
dramatically even within an individual based on biological, psychological,
and social circumstances, so it would be interesting to see if the reproducibility
within an individual can change under different circumstances.
In this study, "reproducible" meant that individuals had similar
findings when tested two weeks apart. If tested two months or even two
years apart, that may not be true. Reproducibility may also become untrue
if there are changes in the same individual's biological, psychological,
or social conditions between tests. If changes occur under different conditions,
that might mean that a person's pain "fingerprint" can change
over time (or if their circumstances change), as well. This pain fingerprint
"plasticity" provides a reason for optimism. That would mean
their experience (the pain the person feels) can be reduced, improved,
or eliminated with the right combination of interventions.
I want people experiencing chronic pain to know that it is a condition
that does not have to last forever. Now, more than ever, there are
treatments (especially those beyond medication therapy) that can help people manage
or eliminate their chronic pain so they can return to living the healthy,
active, and productive lives they use to enjoy.
Dr. Williams’ email answers provided on 6/22/23.