A Treatment Protocol for Patients With Diabetic Peripheral Neuropathy

The progressive symptoms of diabetic peripheral neuropathy (DPN) are some of the most frequent presentations of patients seeking care at the VHA. Patients with DPN often experience unmanageable pain in the lower extremities, loss of sensation in the feet, loss of balance, and an inability to perform daily functional activities.¹ In addition, these patients are at significant risk for lower extremity ulceration and amputation.² The symptoms and consequences of DPN are strongly linked to chronic use of pain medications as well as increased fall risk and injury.³ The high health care usage of veterans with these complex issues makes DPN a significant burden for the patient, the VHA, and society as a whole.

At the William Jennings Bryan Dorn VA Medical Center (WJBDVAMC) in Columbia, South Carolina, 10,763 veterans were identified to be at risk for limb loss in 2014 due to loss of protective sensation and 5,667 veterans diagnosed with DPN were treated in 2014.⁴ Although WJBDVAMC offers multiple clinics and programs to address the complex issues of diabetes and DPN, veterans oftentimes continue to experience uncontrolled pain, loss of protective sensation, and a decline in function even after diagnosis.

One area of improvement the authors identified in the WJBDVAMC Physical Medicine and Rehabilitation Services Department was the need for an effective, nonpharmacologic treatment for patients who experience DPN. As a result, the authors designed a pilot research study to determine whether or not a combined physical therapy intervention of monochromatic near-infrared energy (MIRE) treatments and a standardized balance exercise program would help improve the protective sensation, reduce fall risk, and decrease the adverse impact of pain on daily function. The study was approved by the institutional review board (IRB) and had no outside source of funding.

Background

Current treatments for DPN are primarily pharmacologic and are viewed as only moderately effective, limited by significant adverse effects (AEs) and drug interactions.⁵ Patients in the VHA at risk for amputation in low-, moderate-, and high-risk groups total 541,475 and 363,468 have a history of neuropathy. They are considered at risk due to multiple, documented factors, including weakness, callus, foot deformity, loss of protective sensation, and/or history of amputation.⁴ Neuropathy can affect tissues throughout the body, including organs, sensory neurons, cardiovascular status, the autonomic system, and the gastrointestinal tract as it progresses.

Individuals who develop DPN often experience severe, uncontrolled pain in the lower extremities, insensate feet, and decreased proprioceptive skills. The functional status of individuals with DPN often declines insidiously while mortality rate increases.⁶ Increased levels of neuropathic pain often lead to decreased activity levels, which, in turn, contribute to decreased endurance, poorly managed glycemic indexes, decreased strength, and decreased independence.

Additional DPN complications, such as decreased sensation and muscle atrophy in the lower extremities, often lead to foot deformity and increased areas of pressure during weight bearing postures. These areas of increased pressure may develop unknowingly into ulceration. If a patient’s wound becomes chronic and nonhealing, it can also lead to amputation. In such cases, early mortality may result.^6,7 The cascading effects of neuropathic pain and decreased sensation place a patient with diabetes at risk for falls. Injuries from falls are widely known to be a leading cause of hospitalization and mortality in the elderly.⁸

Physical therapy may be prescribed for DPN and its resulting sequelae. Several studies present conflicting results regarding the benefits of therapeutic exercise in the treatment of DPN. Akbari and colleagues showed that balance exercises can increase stability in patients with DPN; whereas, a study by Kruse and colleagues noted a training program consisting of lower-extremity exercises, balance training, and walking resulted in minimal improvement of participants’ balance and leg strength over a 12-month period.^9,10 Recent studies have shown that weight bearing does not increase ulceration in patients with diabetes and DPN. This is contrary to previous assumptions that patients with diabetes and DPN need to avoid weight-bearing activities.^11,12

Transcutaneous electrical nerve stimulation (TENS), a modality often used in physical therapy, has been studied in the treatment of DPN with conflicting results. Gossrau and colleagues found that pain reduction with micro-TENS applied peripherally is not superior to a placebo.¹³ However, a case study by Somers and Somers indicated that TENS applied to the lumbar area seemed to reduce pain and insomnia associated with diabetic neuropathy.¹⁴

Several recent research studies suggest that MIRE, another available modality, may be effective in treating symptoms of DPN. Monochromatic infrared energy therapy is a noninvasive, drug-free, FDA-approved medical device that emits monochromatic near-infrared light to improve local circulation and decrease pain. A large study of 2,239 patients with DPN reported an increase in foot sensation and decreased neuropathic pain levels when treated with MIRE.¹⁵