Peripheral Neuropathy: A Difficult Diagnosis

As a specialist in conservative treatment of spine pain, I often encounter patients struggling with peripheral neuropathy. There are a couple of causes of peripheral neuropathy. Frequently, it can be correlated with uncontrolled diabetes. Evidence in medical research shows that spinal pathology can have the sequela of peripheral neuropathy. Though the mechanism of action is not entirely understood, we do know that neuropathy can be caused due to a lack of blood and oxygen. If a disc in the lumbar spine (most commonly) is causing stenosis, peripheral neuropathy can be a downstream effect.

Unfortunately, this problematic condition affects 10% of middle-aged adults—the prevalence quadruples to 40% in people over 70 years of age.

Patients suffering from peripheral neuropathy often experience a decreased sensation in their feet. This condition primarily attacks the sensory distribution of the nerves, particularly in the lower extremity. Some literature suggests that this is because the nerves in the legs are so much longer than other nerves in the body. Interestingly enough, taller people are predisposed to this condition. So maybe there is some merit here…

I’m always curious if certain conditions, such as peripheral neuropathy, can be traced back to the origin of the nerve itself. If it’s a nerve disease, wouldn’t it make sense to look at the origin of the nerve, i.e., where it starts? Of course, that would be the spine. The Murphy Study is a hallmark study (conducted through the Department of Veteran Affairs) highlighting the correlation between spinal pathology.

The Spinal Connection

Spinal disorders, particularly those involving disc problems, can lead to peripheral neuropathy in several ways:

1. Nerve Compression: Bulging or herniated discs can compress nerve roots in the spinal canal, causing radiculopathy – a form of peripheral neuropathy[1]. This compression can lead to pain, numbness, tingling, and weakness in the affected limbs.
2. Proximal Peripheral Neuropathy: When a nerve root in the spinal column is damaged or irritated, it can result in proximal peripheral neuropathy[1]. This condition often manifests as leg pain, numbness, tingling, or loss of muscular function in the foot or leg.
3. Chronic Nerve Damage: Even if the initial compression resolves, the spinal nerve tissue may sustain lasting damage, continuing to malfunction and send pain signals to the brain[1].

Pathophysiology of Peripheral Neuropathy

Peripheral neuropathy occurs when there’s damage to the peripheral nervous system – the network of nerves outside the brain and spinal cord. In the context of spinal disorders, this damage often results from:

1. Mechanical Compression: Direct pressure on nerves from bulging or herniated discs.
2. Inflammation: Swelling around the affected area can irritate nearby nerves.
3. Ischemia: Reduced blood flow to nerves due to compression or inflammation.

Challenges in Treatment

Treating peripheral neuropathy related to spinal disorders can be particularly challenging for several reasons:

1. Complex Etiology: The root cause isn’t always obvious, making targeted treatment difficult[1].
2. Varied Progression: Some neuropathies progress slowly over months or years, while others advance rapidly[1].
3. Diverse Manifestations: With over a hundred different types of neuropathies, symptoms can vary greatly depending on the affected nerves[1].
4. Central Sensitization: Prolonged severe pain can lead to changes in the central nervous system, increasing sensitivity to even slight touch[1].
5. Limited Evidence: There’s a lack of high-quality evidence for many treatment modalities, particularly for neuropathy arising from disc herniation and spinal stenosis[3].

Treatment Approaches

Despite these challenges, there are several treatment options available:

1. Conservative Management: This often includes physical therapy, chiropractic care, and medication management[4].
2. Interventional Procedures: Epidural steroid injections have shown positive efficacy in radiculopathy and limited efficacy in spinal stenosis[3][4].
3. Surgical Intervention: In some cases, surgery may be superior to conservative treatments for radiculopathy and stenosis, especially in the short term[3].
4. Pharmacological Therapies: Various medications may be prescribed to manage neuropathic pain, though their efficacy can vary[1][3].
5. Electric or Magnetic Stimulation: These therapies have shown limited efficacy for neuropathic pain after spinal cord injury[3].

Conclusion

Peripheral neuropathy is a complex, multifactorial condition. There is no magic bullet, pill, potion, lotion, medication, or treatment to cure this problem. The pharmaceutical industry is turning away from producing drugs to treat this condition, as efforts to do so thus far have been futile. Conservative treatment like non-surgical spinal decompression can be a viable option for treatment IF a dorsal root ganglion compression in the spine is causing peripheral neuropathy. Many doctors across the country have successfully treated peripheral neuropathy utilizing this type of technology. In my office, I have seen patients report improvements in neuropathic symptoms undergoing a conservative trial of care, including upper cervical spinal care, non-surgical spinal decompression, and class IV laser therapy.

Citations:
[1] https://www.thespineandrehabgroup.com/can-peripheral-neuropathy-be-caused-by-a-bulging-disc
[2] https://virginiafamilychiropractic.com/can-back-cause-neuropathy/
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5573862/
[4] https://www.dukehealth.org/treatments/spine/degenerative-disc-disease
[5] https://www.ncbi.nlm.nih.gov/books/NBK448134/
[6] https://www.dovepress.com/the-american-society-of-pain-and-neuroscience-aspn-evidence-based-clin-peer-reviewed-fulltext-article-JPR
[7] https://www.hhs.gov/sites/default/files/pmtf-final-report-2019-05-23.pdf
[8] https://www.cms.gov/medicare-coverage-database/view/lcd.aspx?bc=0&lcdid=39054&ver=5