Over the past several years, neuromodulation has become more sophisticated and appears to be more effective. One reason for the apparent improved results is the improvement in technology. Due to the improved technology, areas of pain that has previously been difficult to treat with neruomodualtion are showing promising results. In the following article, Drs. Khodavirdi and McDonnell provide examples of the clinical application of the new technology. It is in the clinic where the rubber meets road. Hopefully prospective clinical trials of spinal cord stimulation for diabetic peripheral neuropathy will demonstrate long term efficacy as observed in this case series. Drs. Khodavirdi and McDonnell should be congratulated for making these observations and then reporting them to us.
Lynn Webster, MD, FACPM, FASAM
Ani C. Khodavirdi, PhD (left) and Francis McDonnell, MD
In 2006, over 171 million people worldwide were affected by diabetes. According to the World Health Organization, the number of people with diabetes will double by 2030, rendering it a rising global burden. Present among more than 50% of the diabetic population, diabetic peripheral neuropathy (DPN) is the most common complication of both types I and II diabetes mellitus (DM).1,2 DPN is a heterogeneous disorder that affects proximal and distal peripheral sensory and motor nerves as well as the autonomic nervous systems.3 It is characterized by a superficial burning pain, skin hypersensitivity, and numbness that affects the feet and lower extremities.4 Compromising neuronal integrity and deteriorating peripheral nerve function, DPN leads to sensory loss in the limbs. It also causes foot ulceration and subsequently increases the risk of amputation.3,4 As the most troublesome complication of diabetes, DPN accounts for 50-75% of nontraumatic amputations secondary to foot ulceration and gangrene formation.3,5
Pain associated with DPN falls into several categories, each requiring different forms of intervention. Although prevention by means of glycemic control is the first priority, up to 20% of patients with DPN are afflicted with pain and require active drug therapy.6 Select anti-depressants, anti-epileptics, and opioids have generally been the first-line of pharmacologic treatments for neuropathic pain,7 while topical creams have been used to achieve local control. Alternatives to both oral medications and topical creams have included acupuncture and magnet therapy.6 However, since pain pathways are not well understood, identifying the appropriate treatment remains a challenge for health care providers. The management of neuropathic pain is often difficult, and the available treatment options rarely provide complete relief.6 Neuropathic pain continues to be a physically and emotionally debilitating burden on individuals with DPN due to the limited utility of conventional therapies and their marginal efficacy. The condition negatively impacts work function, social activity, sleep, mood and mental health, and overall quality of life.8,9
Since its inception and first use in 1967, spinal cord stimulation (SCS) has served as an innovative treatment for severe, chronic, and intractable pain.10 Based on the gate control theory of pain proposed by Melzack and Wall in 1965, SCS generates electrical pulses that stimulate the dorsal columns of the spinal cord to produce a tingling sensation known as paresthesia which replaces pain perception in the brain. Specifically, an implantable pulse generator (IPG) nested in a pocket of adipose tissue creates electrical current that is delivered to the dorsal columns via single or dual leads via electrode contacts that rest in the epidural space of the spinal cord. The stimulation is targeted to the painful area by placing the lead(s) at the vertebral level that corresponds to the area of interest on the dermatome map.
Please refer to the June 2007 issue for the complete text. In the event you need to order a back issue, please click here.