without eliciting any additional sensations, adds Dr. Cohen.
It's a minimally invasive procedure that includes 2 steps:
• A trial where the electrodes are placed in the patient via an epidur-
al needle. They're left in for 5 to 7 days to see how much improve-
ment the patient gets and if the patient likes the device.
• If the patient sees improvement and likes the device, then the
device is implanted.
"The success rate is patient-dependent — all these treatments are
patient-dependent — so it's more or less the patient's selection. If they do
really well in the trial, the chances of success are really high," says Dr. Ng.
The devices are used, says Dr. Ng, for patients who don't benefit
from conventional therapy to include injections and for those who are
not candidates for surgery, including some people who have previous-
ly failed back surgery.
"Of course, the patient has to be open-minded. If they are very
focused and very determined that they get better, it can be success-
ful," he says.
3. Therapeutic thermocoagulation
People thought for a long time that radiofrequency ablations — an
electrical current produced by radiowaves that is used to heat up a
small area of nerve tissue, thereby decreasing pain signals from that
specific area — or burning nerves, especially painful nerves, would be
great for reducing pain.
But the problem with burning nerves is that nerves consist of many
different types of nerve fibers, so you don't want to burn a nerve that
transmits sensations of light touch, for example. Or you don't want to
burn nerves that have motor fibers so that your muscles don't work.
Thermocoagulation, or radiofrequency procedures, really are limited
to arthritis, where they can target nerves that only transmit pain infor-
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