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Written by:
Gregory T. Hale,
Ph.D., HSPP, Psychologist
Psychological and
behavioral factors have long been understood to be important in
assessing the suitability of patients for implantable devices.
In the management of chronic pain patients, spinal cord
stimulators, morphine pumps and other devices have been used to
alleviate unremitting pain, to increase functional ability, and to
allow patients to discontinue or limit the chronic use of narcotic
medication. However,
selecting appropriate patients for the use of such devices is an
important process and needs to be better understood.
Behavioral and
psychological factors clearly have been found relevant in excluding
individuals. Although high success rates, often 60 to 80 percent, are
reported in utilizing spinal cord stimulators for the relief of
chronic back pain, these numbers usually represent the population of
psychologically screened patients.
That is, this group represents the absolute best candidates for
further medical intervention. Thus, even among the candidates who have already been
determined to be most suitable, only 60 to 80 percent benefit. Thus, psychological evaluations for determining suitability
of an implantable device such as spinal cord stimulator provide
physicians assistance in determining and understanding the possible
outcome prior to implanting the device itself.
The December 1996
issue of Pain Forum
focused on the issue of determining the psychological suitability of
implantable devices. Multiple
factors have been found to be relevant in determining which
individuals should be considered and which should not.
The exclusionary screening criteria identified by Nelson, et
al, (1996) identifies the psychological-behavioral features that
should be evaluated to assess a patient's
qualification. While the
screening criteria do not represent a perfect algorithm for
determining psychological suitability for implantable devices, it
represents the best model to identify those factors which are most
relevant in determining which patients will benefit from this type of
treatment.
The factors
utilized to assess spinal cord stimulator patients include
psychological and behavioral features. Often psychological testing and
a review of medical records are necessary to fully understand factors
related to a person's
response to pain. Moreover,
some patients make an attempt to present as highly desirable in an
effort to influence the physician about the need
for such an intervention. In addition, the presence of litigation
either in the form of Worker's Compensation or personal injury claims can also influence an
individual's
desire for such devices.
An appropriate
psychological examination will consider several factors. First, the
psychological stability of the patient, or the role of psychosis or
other serious mental illness, needs to be assessed.
A psychologically troubled individual can have a pain condition
as real as that of anyone else. However, if a psychological illness,
particularly a psychotic condition, is significant, it will increase the
likelihood of highly focused somatic preoccupations. Consequently,
success of a spinal cord stimulator in such a case is extremely remote.
Moreover, actively suicidal or homicidal patients are poor candidates as
their impulsiveness and emotional disturbance will obviously affect
their thinking and ability to be stabilized by such an intervention.
In addition, patients with poorly treated major depression or
other mood disturbances are also contraindicated. Often providing
treatment to stabilize the mood disorder is necessary prior to
proceeding with invasive medical care.
That is, moderate to severe depression should first be treated
with medication and psychotherapy.
The presence of a
somatization disorder or other somatoform pain disorder involving vague
physical complaints that do not seem to correlate with organic findings
is also considered one of the exclusionary criteria, especially with
chronic pain patients. This
particular feature needs to be carefully examined as some amount of
somatization is common and should be expected with the chronic pain
population. Nevertheless, a propensity for extreme somatization in
conjunction with other factors clearly will impact the response to
spinal cord stimulator implantation. Even when pain complaints can be
documented and correlated with obvious physical findings, an exaggerated
pain response can be found and ultimately will influence the individual's
symptom perception. Obviously alcohol or drug dependency of either
illegal or prescription drugs should be carefully monitored.
Excessive drug seeking behavior should first be controlled prior
to further consideration. Compensation or litigation should generally be
resolved or at least excluded as a possible motivating factor,
particularly if a decision regarding the implantation of the spinal cord
stimulator is dependent on this litigation.
In some cases, long term disability status or compensation issues
are dependent on continued medical treatment.
Thus, a decision to
proceed with spinal cord stimulator may be motivated not by a desire to
manage pain more effectively but rather to maintain disability or
compensation status.
A lack of
appropriate social support has historically always been a critical
variable in the success of chronic pain patients to better manage their
condition. It is advisable
to have family members or close friends be committed to the process of
evaluation and treatment with the spinal cord stimulator.
This aids not only in supporting the individual as he goes
through the process but also in assisting with basic self-care
activities that may be necessary. Finally, behavioral and cognitive
deficits that compromise reasoning, judgment and memory also will
interfere with the ability of the patient to adequately participate in
the treatment process. The
individual whose cognitive functioning has either deteriorated or is
compromised by various factors will be unable to provide sufficient
information to accurately assess the degree to which the procedure is
suitable and helpful. Thus, valid reporting of information, particularly
levels of pain or position, cannot be expected from the patient who is
cognitively compromised or emotionally overwhelmed.
Understanding the
role of these factors and considering each of these factors as part of
exclusionary criteria aids the physician, the patient and those
providing assistance to the pain patient. Moreover, decisions related to
further invasive treatment are not simply based on an effort to resolve
pain but rather on behavioral factors that take into account the full
context of the individual's life
and his response to medical treatment.
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