movement, and the act of raising a glass of water to the mouth an
embarrassing impossibility. However, with an instantaneous initiation of
the electrical signal from the pulse generator unit, the tremors stop. For
the first time in years, taking a drink of water is a possibility, and the
patient (and her family) burst into tears. I defy you—do an internet search
and watch a few videos of DBS units being turned on and try to not weep.
DBS has been used over 150,000 times around the world, with about
10,000 such operations per year in the United States. The last year with
complete United States implant data is 2014, and there were an estimated
20,000 SCSs placed. Similarly, there were 7,000 sacral nerve stimulators
and 2,000 vagus nerve stimulator operations in 2014. All told, there were
approximately 35,000 neuromodulation operations performed in America
in 2014.
“A recent study estimates the global neuromodulation market—
including deep-brain stimulation along with technologies such as spinal
cord stimulation, and transcranial magnetic stimulation—at €3.31 billion
($3.65 billion) in 2015 (MarketsandMarkets). The market is projected to
grow at a CAGR of 11.2% to reach €5.62 billion ($6.20 billion) by
2020.”^34 Because DBS placement is more effective than medicine in early
stage Parkinson’s, and because its effectiveness continues for years, it is a
powerful weapon in the battle against movement disorders.
It is striking that DBS is also being used now for chronic depression,
dystonia, epilepsy, obsessive-compulsive disorder, Tourette’s syndrome,
and even Alzheimer’s disease. In a perspective article in the New England
Journal of Medicine, Michael Okun concluded, “DBS therapy is usually
considered only after all other treatments have been exhausted, but
becoming ‘bionic’ has provided many patients with a new lease on life.
Thanks in large part to the contributions of two extraordinary scientists
[DeLong and Benabid], we have entered the era of human neural-network
modulation.”^35
Deeply placed wire electrodes with low frequency current have now
been used around the world for three decades. Interestingly, scientists are
not exactly sure of the mechanism of action, but then again, we still don’t
fully understand how many anesthetics work during surgery, and how
many of our disease-modifying drugs function. We just know that they
work.