Brian P. Jacob, David C. Chen, Bruce Ramshaw, Shirin Towfigh (eds.) - The SAGES Manual of Groin Pain-Springer International Publishing (2016)

3. Complex Regional Pain Syndrome Types I and II
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nerve blockade plateaus, other treatments should be considered.
Intrathecal use of morphine and baclofen has also been studied in the
treatment of CRPS [ 23 ].
Intravenous regional anesthesia refers to the use of clonidine and
lidocaine, as described by Reuben and Sklar. They showed complete
pain relief after 4–6 sessions of such treatment [ 24 ].
Spinal cord stimulation has been shown in a randomized control trial
to alleviate pain among patients with refractory CRPS [ 25 ]. Furthermore,
Harke et al. found improvement in pain among those who had previously
responded well to sympathetic block, with reduction in their level
of pain. This was a prerequisite to spinal cord stimulation [ 26 ].
Peripheral nerve stimulation and peripheral field stimulation are also
viable options when conventional treatment protocols have not provided
adequate relief [ 27 ]. The use of ultrasound-guided intervention to help
directly visualize the affected nerve has allowed for the use of direct
visualization techniques, such as imaging, to implant peripheral electrodes
without need for surgical dissection. Others have used peripheral
field stimulation for localized extremity pain or regional pain rather than
directly stimulating the nerve [ 28 ]. Finally, the stimulation of the dorsal
root ganglion has also been considered [ 29 ]. This offers more specific
targeting of a regional area and may have value in treatment of refractory
conditions.
Other more novel interventional techniques for treatment of CRPS
have promising outcomes but have not been studied extensively. One
such treatment is transcranial magnetic stimulation. In one study, continued
stimulation of the motor cortex by TMS of the affected side showed
a decrease in pain as compared to sham stimulation [ 30 ].
Although interventional treatment has been a hallmark of decreasing
pain and improving symptoms, the use of these interventions has longerterm
success when used with conservative treatment including physical
and behavioral therapies (see Fig. 3.1 ).
Summary
The current diagnostic criteria for CRPS are delineated in Table 3.1 .
However, it is important to understand that the vast majority of patients
who have chronic and/or acute pain that is disproportionate to the inciting
injury do not fulfill all the diagnostic criteria for CRPS. And yet, at
the same time, care must be taken to appropriately treat these patients
with a structured plan of early pharmacological therapy, interventional