The chronic pain puzzle – Is DBS the missing piece?

Pain – and how we approach it – is a perpetual puzzle for all member of our health-care system. Physicians scratch their heads in finding ways to prevent pain and treat that which persists after their patients leave the hospital, but this is an uphill battle. Those who continue to experience pain have earned contracts for a lifelong journey with their pain. Chronic pain, especially back pain, contributes more than $500 billion to annual health-care costs [1] and disables more than 20% of the workforce [2]. However, many potential solutions are themselves expensive puzzle pieces that can be misunderstood or incompatible with the patients they attempt to treat.

Prescription painkillers, or “opioids,” while touted as a cheap and effective therapy for many different kinds of pain, have consistently made headlines because of the rapid increase in narcotic-related deaths over the past decade. [3] However, they are not without their side effects, which are not uncommon – more than 20% of patients will experience constipation, nausea, and itching, and over-sedation. Higher-risk patients may experience breathing issues, especially if they have been receiving similar medications or have medical problems that prolong the effects of these pills. A recent CDC survey reported that a quarter of patients with legitimate prescriptions are incorrectly using or storing these medications, increasing the risk for overdose or harm to their loved ones in close proximity. [4]

The crisis has called for physicians and researchers to work ever so closely together to produce alternative treatments that are effective in patients that are nowadays living longer with more complex medical problems.

One of these therapies include deep brain stimulation (DBS) therapy, a treatment modality that has long been studied and evaluated for use in several brain-related disorders. Since the 1970s, scientists have discovered specific “targets” within the brain that conduct irregular patterns of brain electrical activity, and these patterns have been associated with different pain syndromes. Initial interest in this technology focused on the use of DBS to treat movement disorders, including Parkinson’s Disease. Many movement disorders are associated with pain itself, and patients reported an increase in their quality of life and pain control with further improvements in the procedure over time.

In the past 30 years, collaborations between neurosurgeons, pain specialists, and researchers led to its use in patients with chronic pain syndromes, with significant success with patients with cluster headaches and back pain. [5] Current research is exploring its use in pain after stroke or loss or a limb (e.g. phantom limb pain) [6]. Treatment effect is even more significant with patients who have previously failed to realize adequate pain relief with escalating conventional treatments methods, including:

1) over-the counter medications (e.g. Tylenol, Advil)

2) prescription opioid therapy

3) neuropathic pain treatments (e.g. Neurontin, Lyrica)

4) complementary therapies (e.g. acupuncture),

5) interventional pain therapies (e.g. injections for nerve block, radiofrequency and chemical denervation).

It is natural to have questions about the overall safety and approach of this “brain surgery.” After a referral to a neurosurgeon with specialized experience, patients receive routine pre-operative medical and surgical evaluations, including a thorough review of pain complaints, triggers, and expectations for eventual relief. On the day of the procedure, the patient is placed under general anesthesia, and a small device called a pulse generator (e.g. neurostimulator) in is placed in the neck or abdomen. Leads connect the generator to the “target” areas in the brain, and the integrity of the connections and the generator are tested before the end of the procedure. Recovery in the hospital lasts a few days, and the patient may receive closer (i.e. around-the-clock) monitoring for the first 24 hours for unlikely complications including bleeding, infection and seizures. After leaving the hospital, a few patients may report slight changes in mood and personality. DBS lead placement may be responsible for the majority of these complaints, and it is very important to follow-up with the surgeon within 1-2 weeks after the initial procedure.

DBS has proven to be beneficial for patients with the most recalcitrant types of pain. In combination with conventional and alternative treatments (e.g. multimodal therapy), DBS provides an essential piece of the pain puzzle that may be beneficial with other pain syndromes and clinical disorders syndromes in the future.


References

[1] Institute of Medicine Report from the Committee on Advancing Pain Research, Care, and Education: Relieving Pain in America, A Blueprint for Transforming Prevention, Care, Education and Research. The National Academies Press, 2011. http://books.nap.edu/openbook.php?record_id=13172&page=1.

[2] Peter D. Hart Research Associates. Page 3. KEY FINDINGS. Americans in Pain. Much of America is hurting: the majority of adults (57%) in this country have … http://www.researchamerica.org/uploads/poll2003pain.pdf

[3] Vivolo-Kantor AM, Seth P, Gladden RM, et al. Vital Signs: Trends in Emergency Department Visits for Suspected Opioid Overdoses — United States, July 2016–September 2017. MMWR Morb Mortal Wkly Rep 2018;67:279–285. DOI: http://dx.doi.org/10.15585/mmwr.mm6709e1

[4] QuickStats: Percentage of Emergency Department Visits That Had an Opioid Ordered or Prescribed, by Age Group — National Hospital Ambulatory Medical Care Survey, United States, 2006–2015. MMWR Morb Mortal Wkly Rep 2018;67:344. DOI: http://dx.doi.org/10.15585/mmwr.mm6711a8

[5] Lempka SF, Malone DA, Hu B, Baker KB, Wyant A, Ozinga JG, Plow EB., Pandya M, Kubu CS, Ford PJ, Machado AG. Randomized clinical trial of deep brain stimulation for poststroke pain. Ann Neurol. 2017 May;81(5):653-663. doi: 10.1002/ana.24927.

[6] Bittar, RG. et al. Deep brain stimulation for pain relief: A meta-analysis. J Clin Neurosci. 2005 Jun;12(5):515-9. DOI:10.1016/j.jocn.2004.10.005