blocks are also known as regional anesthesia. This is a set of techniques
developed by injection anesthesiologists as diagnostic and therapeutic tools.
Some blocks are performed in and around the spinal nerves and spinal cord
and are known as Spinal Blocks. Other blocks
are done on more peripheral nerves or sympathetic ganglia.
blocks can help to pinpoint and differentiate a lesion. For instance, in a
patient with lancinating pain radiating to a leg, allodynia of the foot and
lower leg and temperature changes a selective nerve root block and a sympathetic
block can help determine whether the pain is coming from an injured nerve
root (CRPS 2) or activation of the sympathetic nervous system (CRPS 1). Blocks
can often determined if the pain is coming from a local site or is referred
from a more distant location. At other times there may be obvious pathology
noted on imaging studies, but doing provocative procedures may show that the
pain is actually coming from a more subtle injury. An example of this would
be concordant pain evoked by a discogram
done on a mildly degenerative or normal looking L4-5 disc, with an obvious
herniation at the L5-S1 disc on MRI.
blocks can make a dramatic difference in acute and chronically painful conditions.
Examples of this include the following. Serial sympathetic blocks can eliminate
Complex Regional Pain Syndrome 1 (CRPS 1) in many patients, especially if
caught early. This can be effective even later in the evolution of the condition.
At times a continuous epidural infusion can be used to dramatically decrease
symptoms from painful degenerative discs. Celiac plexus blocks can help dramatically
decrease the pain of pancreatic cancer. Opioids delivered in an epidural catheter
can provide excellent post operative analgesia. Therapeutic blocks can be
short lived in their effectiveness or may have long lasting effects.
may also point out the value of other procedures. Discograms can show the
need for fusion surgery or IDET procedures. Selective Nerve Root Blocks can
confirm the efficacy of trying spinal cord stimulator implants. Opioid epidural
infusions can point to the utility of using an intrathecal narcotic pump.
Blocks of the facet joints and medial ramus of the nerve root can predict
whether facet joint rhizotomies are likely to help.
are a very important aspect of diagnosing and treating pain disorders. Although
invasive treatments are generally reserved for failure of more conservative
measures, diagnostic and therapeutic blocks are an exception to this rule.
In general they can be very effective early on in dealing with acute and chronic