Approximately 30-40 % of peripheral neuropathy cases are idiopathic (due to unknown causes). Well-defined causes or risk factors for developing peripheral neuropathies include:

• Diabetes Mellitus – most common cause, ~30% of peripheral neuropathies. ~60% percent of all people with diabetes suffer from peripheral neuropathy (1)
• Alcoholism
• Autoimmune disorders, such as Guillain-Barre syndrome
• Cancer related, or cancer treatment related (Chemotherapy-induced neuropathy)
• Chronic kidney failure
• Connective tissue/autoimmune disease, such as rheumatoid arthritis, lupus, amyloidosis, Guillain-Barre syndrome, Lyme’s disease, and sarcoidosis
• Infectious disease, such as Lyme disease, HIV/AIDS, and Hepatitis B
• Nerve impingements such as Carpal or Tarsal tunnel syndrome
• Vitamin deficiencies

Peripheral neuropathy usually affects both sides of the body. Symptoms are usually noticed first in the toes. If the disease progresses, symptoms may gradually move up the legs; if the mid-calves are affected, symptoms may develop in the hands as well.

Symptoms typically include pain which can vary from dull, aching, and throbbing to sharp, stabbing, and burning. Pain is often accompanied by tingling and numbness and hypersensitivity to light touch. Any of these painful sensations can greatly reduce physical function and limit the ability to walk. When motor nerves become involved in the neuropathy, muscle weakness, cramps, twitching, and muscle atrophy or wasting can occur. As nerve damage progresses over time, there is loss of sensation. The ability to sense pain and the sense of balance may be partially or completely lost, which greatly increases the risk of falls and injury.

Peripheral neuropathy is diagnosed based upon a medical history and physical examination of the feet. During an examination, there may be signs of nerve injury, including:

• Loss of the ability to sense vibration and movement in the toes or feet (eg, when the toe is moved up or down)
• Loss of the ability to sense pain, light touch, and temperature in the toes or feet
• Loss or reduction of the Achilles tendon reflex

More extensive testing, including nerve conduction studies, nerve biopsy, or imaging tests (eg, X-ray or computed tomography [CT] scan), is not usually needed to diagnose peripheral neuropathy.

There are four main components of peripheral neuropathy treatment:

• Control of blood sugar levels (for diabetics)
• Lifestyle interventions, specifically diet and exercise
• Care for the feet to prevent complications
• Control of pain caused by neuropathy — Neuropathic pain can be difficult to control and can seriously affect your quality of life. Neuropathic pain is often worse at night, seriously disrupting sleep.

There are several medications that are useful for the treatment of diabetic neuropathy and have been approved by the US Food and Drug Administration (FDA), including duloxetine and pregabalin. Other medications are also useful, including tricyclic medications (eg, amitriptyline), gabapentin, tramadol, and alpha-lipoic acid.

Unfortunately, many of the peripheral neuropathies are progressive, and systemic oral medication or local topicals can become less effective over time. If the pain or disability of peripheral neuropathic pain is severe and traditional medical management is not providing effective relief, spinal cord stimulation (SCS) may be an option. In fact, one of the most common studied diagnoses utilizing SCS for pain is diabetic peripheral neuropathy (DPN). A systematic review of traditional spinal cord stimulation (SCS) studies used to treat DPN reported >50% relief in 63% of patients (2). However, SCS has its shortcomings in treating peripheral neuropathy. Stimulation is applied to the spinal cord but does not target individual nerves, making it difficult for treatment effects to cover specific body parts like the distal legs and feet, which are affected most in peripheral neuropathies.

We published two case reports on the treatment of peripheral neuropathies with DRG-S, one detailing improvements in diabetic neuropathy and one in chemotherapy-induced neuropathy (3,4) (have images of papers on screen to click and take patient to article). DRG-S likely improves the symptoms of peripheral neuropathy through multiple mechanisms, giving it several advantages over SCS when treating peripheral neuropathies.

DRG-S may provide better coverage for peripheral neuropathies because it directly targets the individual nerve fibers innervating the feet and legs to block pain signal transmission (5–7). Additionally, stimulation reaches the spinal cord to further disrupt incoming pain signals. Stimulation can also spread in the opposite direction, towards the small nerve fibers of the sympathetic nervous system which are typically damaged the most in peripheral neuropathies. DRG-S has a direct effect on these small nerve fibers (Aδ and C fibers), which not only transmit pain, but also control local blood flow and inflammation. Stimulation effectively disrupts signaling from these fibers, thereby reducing local inflammation and blocking constriction of blood vessels to increase local blood flow and tissue oxygenation. This is an important consideration for peripheral neuropathy patients as the increased blood flow often improves the symptoms of peripheral neuropathy.

1. Kaur S, Pandhi P, Dutta P. Painful diabetic neuropathy: an update. Ann Neurosci [Internet]. 2011 Oct [cited 2020 Mar 27];18(4):168–75. Available from: http://www.ncbi.nlm.nih.gov/pubmed/25205950
2. Pluijms WA, Slangen R, Joosten EA, Kessels AG, Merkies ISJ, Schaper NC, et al. Electrical spinal cord stimulation in painful diabetic polyneuropathy, a systematic review on treatment efficacy and safety. Eur J Pain [Internet]. 2011;15(8):783–8. Available from: http://dx.doi.org/10.1016/j.ejpain.2011.01.010
3. Chapman KB, van Roosendaal B-K, van Helmond N, Yousef TA. Unilateral Dorsal Root Ganglion Stimulation Lead Placement with Resolution of Bilateral Lower Extremity Symptoms in Diabetic Peripheral Neuropathy: A Case Report. Cureus. 2020;
4. Groenen PS, Van Helmond N, Chapman KB, Helmond N Van, Chapman KB, Van Helmond N, et al. Chemotherapy-Induced Peripheral Neuropathy Treated with Dorsal Root Ganglion Stimulation. Pain Med. 2019;20(4):857–9.
5. Deer TR, Levy RM, Kramer J, Poree L, Amirdelfan K, Grigsby E, et al. Dorsal root ganglion stimulation yielded higher treatment success rate for complex regional pain syndrome and causalgia at 3 and 12 months: a randomized comparative trial. J P [Internet]. 2017 Apr 1 [cited 2019 Aug 9];158(4):669–81. Available from: http://www.ncbi.nlm.nih.gov/pubmed/28030470
6. Van Buyten J-P, Smet I, Liem L, Russo M, Huygen F. Stimulation of Dorsal Root Ganglia for the Management of Complex Regional Pain Syndrome: A Prospective Case Series. Pain Pract [Internet]. 2015 Mar;15(3):208–16. Available from: http://doi.wiley.com/10.1111/papr.12170
7. Deer TR, Levy RM, Kramer J, Poree L, Amirdelfan K, Grigsby E, et al. Comparison of Paresthesia Coverage of Patient’s Pain: Dorsal Root Ganglion vs. Spinal Cord Stimulation. An ACCURATE Study Sub-Analysis. Neuromodulation. 2019;2018.