++
Indications for surgical interventions in the treatment of chronic
pain continue to evolve as we learn more about the pathophysiology
and mechanisms of chronic pain. Recent advances in technology and
availability of newer and better analgesics have also helped us
rely more on neuromodulation and neuroaugmentation rather than neuroablation.
Establishment of multidisciplinary pain centers, formal fellowship
training in pain medicine, and popularity of minimally invasive techniques
has enabled clinicians from various disciplines to perform procedures
that were once performed only by neurosurgeons. Surgical procedures
that are used to relieve pain, and are not discussed in detail elsewhere
in this book, can be divided into three major categories (Table
75-1).
++
+
I. Techniques that attempt to correct the disordered
physiology of nerves without creating a lesion.
II. Destructive procedures.
III. Procedures in which a device is implanted to stimulate
an analgesia-producing mechanism in the central nervous system.
++
The first category of neurosurgical procedures for pain control
includes operations designed to relieve constriction of peripheral
nerves, spinal nerve roots, dorsal root ganglia, or cranial nerves. These
decompressive operations are sometimes elegant and often curative.
Their use is restricted to specific well-defined syndromes in which
the site of disordered nerve physiology can be predicted. The prediction
usually is based on radiologic studies, electromyography, nerve
conduction studies, and after careful clinical examination. Most
procedures of this type have high success rates. Whenever possible,
they should be used in preference to destructive lesions.
++
The reason for the success of nerve decompression is not entirely
clear since it is not always understood why pressure on a nerve
causes pain. Not all sites of nerve distortion are associated with
chronic pain. For example, in a large series of patients investigated
for possible acoustic nerve tumors, myelograms frequently showed
incidental disc protrusions. Asymptomatic lesions severe enough
to distort spinal nerve roots were identified in one third of cases.2 These
well-defined disc protrusions with nerve root compression were ...