THE PERIPHERAL NEUROPATHY LAB

Peripheral neuropathy can result from traumatic injuries, infections, metabolic problems, inherited causes and exposure to toxins. One of the most common causes is diabetes. People with peripheral neuropathy generally describe the pain as stabbing, burning or tingling.

Neuropathy is damage or dysfunction of one or more nerves that typically results in numbness, tingling, muscle weakness and pain in the affected area. Neuropathies frequently start in your hands and feet, but other parts of your body can be affected too.

"Yes, I Have Changed Because

My Old Version Was to Weak"

PERIPHERAL NEUROPATHY

REDUCING THE PAIN ASSOCIATED WITH PERIPHERAL NEUROPATHY

Peripheral neuropathy can result from traumatic injuries, infections, metabolic problems, inherited causes and exposure to toxins. One of the most common causes is diabetes. People with peripheral neuropathy generally describe the pain as stabbing, burning or tingling.

Neuropathy is damage or dysfunction of one or more nerves that typically results in numbness, tingling, muscle weakness and pain in the affected area. Neuropathies frequently start in your hands and feet, but other parts of your body can be affected too.

HOW DOES PEMF HELP PERIPHERAL NEUROPATHY?

Diabetic neuropathy is a common microvascular complication of diabetes over time and one of the major cause of nontraumatic amputations. A widely-accepted definition of diabetic peripheral neuropathy is “the presence of symptoms and / or signs of peripheral nerve dysfunction in people with diabetes after exclusion of other causes”.  Depending on criteria, DPN is estimated to occur in 50–90% of individuals with diabetes for more than 10 years. The impairment of peripheral nerve function in diabetic individuals should be regarded not as a neurological complication but as a neurological manifestation of the disease. It approaches 50% in most diabetic population, mainly with painful symptoms.  It may present as symmetric polyneuropathies, focal and multifocal neuropathies and mixed form of neuropathy. Distal symmetric sensorimotor polyneuropathy is the most common type of diabetic neuropathy and is characterized by the progressive loss of sensation and less frequently, motor function in a distal to proximal gradient. Treating neuropathy is a difficult task for the physician and most of the conventional pain medications primarily mask symptoms. and have significant side effects and addiction profiles. In the realm of physical medicine acupuncture, magnetic therapy, yoga have been found to provide benefit. One of the approaches which is currently of clinical interest includes low-frequency pulsed magnetic fields, which have analgesic, neurostimulatory, trophic, and vasoactive actions. This article introduces and discusses the efficacy of low-frequency pulsed electromagnetic field which induces quasirectangular currents that can depolarize, repolarize, hyperpolarize neurons and can potentially modulate neuropathic pain and nerve impulse. It stimulates the cell power stations and enhances cell metabolism[10] resulting in higher mucosal content of RNA, DNA and improve the microcirculation due to an increased release of calcitonin gene related peptide-CGRP, a bioactive messenger responsible for the formation of capillaries in wound area.

The aim of the present research was to study the effects of different frequencies (600 Hz, 800 Hz) of PEMF on motor nerve conduction parameters and pain control.

In the present study, pulsed electromagnetic field therapy (600 and 800 Hz) was explored to study its effect on the state of segmental peripheral neuromotor apparatus and neuropathic pain experienced by patients. The primary aim of the study was to evaluate the effect of different frequencies of PEMF in diabetic polyneuropathy. In DPN, the pain may result due to various reasons such as increase in different signals from degenerating nociceptive afferent fibers, depolarization because of dysregulation of normal sodium, calcium and potassium channel activities. It is well known that a biological system exposed to a physical stimulus (PEMF) is able to detect its presence and to modify its own biological activity depending on the characteristic of the applied stimulus such as mechanic, electric, or magnetic. In particular, static and time varying magnetic fields have been shown to alter animal and human behaviors such as pain perception. The pain relief in experimental groups 1 and 2 could be attributed to the effect that magnetic fields affects pain perception by direct effects in form of neuron firing, calcium ion movement, endorphin levels, acupuncture action, and nerve regeneration. A gating response with simultaneous stimulation of the Aδ fibers producing an inhibitory antinociceptive effect on C fibers which is compatible with Melzak–Wall Hypothesis. The pain is most likely to arise from increased activity of injured small – diameter regenerating fibers, which fire rapidly and at abnormally low thresholds. The PEMF influence diabetic neurons and cell membrane of cutaneous nociceptors thereby inducing change in the cellular and pericellular microenvironment. The possible reason of pain reduction in group 3 is persistent controlled glycemic control. The strict glycemic control is a best measure to halt deterioration of DPN.

The motor nerve conduction parameters (latency and NCV) showed significant improvement in group 1, 2 with better mean values in group 1. As demonstrated by Fagerberg's, DPN is a result of diabetic angiopathy and found the correlation between neuropathic symptoms and duration of diabetes and histological abnormalities of the vasa nervorum. The decrease in motor nerve conduction velocity (MCV) can be explained as a result of abnormality in the vasa nervorum. The experimental groups showed improvement in distal latency, NCV after treatment which can be attributed to indirect effect of PEMF, that is it augments angiogenesis by stimulating endothelial release of fibroblast growth factor beta – 2 (FGF – 2). Smith[31] found that PEMF stimulate the arteriolar microvessel diameters in cremester muscle, which further support that it improves the microenvironment for the tissues leading to regeneration.  Other probable reason for the improvement may be that it stimulates neurotrophic factors that is known to play an important role in the development, maintenance, and survival of neuronal tissues. Few studies suggested that endoneurial capillaries in peripheral nerves of the diabetes are thickened and perineurial basement membrane are widened. A permeability disorder at the blood nerve or blood perineurial barrier in diabetics could lead to endoneurial metabolic derangements, however possibly resulting in neuropathy. PEMF by targeting at increased circulation and anti inflammatory effects combined with the pain relief and restoration of normal nerve conduction lead to reversal of the damage that cause the peripheral neuropathy. Recently, it has been observed that PEMF modulates the neurite growth in vitro and nerve regeneration in vivo, which further explains the improvement obtained in results of group 1 and 2. None of the group showed significant changes in amplitude reading obtained in pre and post-treatment reading. The probable reason could be that amplitude of compound muscle action potential correlate with the number of nerve fibers recruited. As DPN is best classified as axonal neuropathy, in that predominant neuropathic feature is nerve fiber loss. The effects of PEMF is to trigger a biologic response such as cell proliferation that represent the basic effect to explain some relevant results. It enhances nerve regeneration and accelerates recovery in experimentally divided and sutured peroneal nerve which can improve number of nerve fiber and thereby amplitude achieved in nerve conduction study. No difference in pre and post reading of amplitude could be attributed to short duration of treatment, which was inadequate to get the positive changes in amplitude. Comparative analysis showed non-significant differences in group 1, 2 after treatment. The mean difference was found to be more in group 1 (600 Hz) in both legs except NCV mean value which was higher in left leg of group 2 (800 Hz). The probable reason for this could be small sample size, short duration of study and individual variations.

In summary, it can be concluded that available data provide the evidence that PEMF treatment has the potential to modulate neuropathic pain and nerve impulse. It may be due to decrease in endoneural hypoxia, perineural edema, ischemia of peripheral nerves, and improved microcirculation that leads to positive changes after treatment sessions. The limitations of the study were small sample size, short term study, exclusion of patients other then distal symmetric polyneuropathy, and lack of follow-up.

RECENT STUDY

The study was carried out to evaluate and compare the effect of low power, low frequency pulsed electromagnetic field (PEMF) of 600 and 800 Hz, respectively, in management of patients with diabetic polyneuropathy.

 

SETTINGS AND DESIGNS:

The study was a randomized controlled trial performed in Guru Nanak Dev University and Medical College, Amritsar, India with different subject experimental design.

 

MATERIALS AND METHODS:

Thirty subjects within an age group of 40–68 years with diabetic polyneuropathy stages N1a, N1b, N2a were randomly allocated to groups 1, 2, 3 with 10 subjects in each. Group 1 and 2 were treated with low power 600 and 800-Hz PEMF for 30 min for 12 consecutive days. Group 3 served as control on usual medical treatment of diabetic polyneuropathy (DPN). The subjects with neuropathy due to any cause other than diabetes were excluded. The pain and motor nerve conduction parameters (distal latency, amplitude, nerve conduction velocity) were assessed before and after treatment.

 

STATISTICAL ANALYSIS:

Related t-test and unrelated t-test were used for data analysis.

 

RESULTS:

Significant reduction in pain and statistically significant (P<0.05) improvement in distal latency and nerve conduction velocity were seen in experimental group 1 and 2.

 

CONCLUSIONS:

Low-frequency PEMF can be used as an adjunct in reducing neuropathic pain as well as for retarding the progression of neuropathy in a short span of time.