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10 Articles in Volume 16, Issue #9
Health and Economic Benefits of Exercise Programs for Seniors
Role of Physical Activity in Managing Chronic Pain in Older Adults
Levorphanol: An Optimal Choice for Opioid Rotation
Incorporating Functional Medicine Into Chronic Pain Care
Expanded Use of EMG-NCV Helps Guide Treatment of Lower Extremity Neuromuscular Disorders
Application of Acupuncture to Treat Low Back Pain
People With Sickle Cell Trait at Greater Risk of Rhabdomyolysis
A Case of Statin Therapy in a Patient With Rhabdomyolysis
Overview of Exertional Rhabdomyolysis
Benzodiazepines and Opioids: Only Trained Pain Practitioners Should Prescribe

Expanded Use of EMG-NCV Helps Guide Treatment of Lower Extremity Neuromuscular Disorders

This once-popular test is again being recommended as a cost-effective alternative for the diagnosis of lower extremity nerve complaints.

Although the most common complaints of patients seeking chiropractic evaluation are low back pain, neck pain, and headache, many patients present with extremity complaints—weakness, numbness, burning, tingling and sciatica. The differential diagnosis of lower extremity pain includes several neuropathic conditions, including radiculopathies, plexopathies, entrapment neuropathies, and sensorimotor polyneuropathies.

The role of electrodiagnostic testing (EDX), including electromyography (EMG) and nerve condition velocity (NCV), has been well established for all of these conditions, and it is considered the gold standard for diagnosing both radiculopathies and sensorimotor polyneuropathies.1-5 Unfortunately, this test appears to be underutilized. Instead, physicians refer most patients for computerized tomography (CT) or expensive magnetic resonance imaging (MRI) scans that, in our opinion, do not accurately diagnose the cause of the patient’s symptoms or provide the physiologic information with which to guide his or her treatment.

We hypothesized that digitized plain x-ray examination and needle EMG-NCV testing, both performed in our clinic, would allow accurate and immediate diagnosis of all extremity complaints in a cost-effective manner. Furthermore, immediate treatment could be initiated for all conditions based on the EDX findings.

Study Overview

In the chiropractic/health and wellness clinic, we initiated a comprehensive neuropathy treatment program in 2011 based on the results of a convenience study of 551 patients with the ReBuilder electrical system.6  This device is registered with the Food and Drug Administration as a 510(k) pre-amendment version of a TENS unit but delivers 2 simultaneous signals (1 to nerves and 1 to muscles) at low frequency (7.83 Hz).

The nerve signal imitates the natural waveform of a healthy neuron and is designed to allow time for repolarization. The signals are delivered via cutaneous electrodes on the feet or through a conductive solution in a split-compartment water bath. Because the signal travels from foot to foot, the lower spinal cord, legs, and pelvis are recruited. The study showed that pain scores decreased significantly within 10 days of treatment (P<0.0001) and that quality of life was improved in 91% of patients after 1 month.6

We performed lower extremity EMG-NCV studies in 208 consecutive patients in order to guide their treatment plans. This report details the clinical and electrodiagnostic findings in this group of patients with lower extremity symptoms and correlates the clinical impressions at the initial examination to the later electrodiagnoses.

Although the initial visit included medical and chiropractic evaluations, a complete neuropathy evaluation was not performed, and diagnostic codes were assigned based on the screening evaluations (Table 1). In addition, data analyses included a comparison of the clinical diagnosis at the time of initial screening examination with those determined by EDX.

Patient Population

Every patient who presented to our clinic had an initial history and physical examination by both the chiropractic and medical staff. Frequently, the examination was performed by both the physician (or physician assistant) and chiropractor concomitantly—both for enhancement of information sharing and to save time for the patients and clinicians.

From February 2010 to February 2013, 403 consecutive patients with upper and/or lower extremity pain that was thought to be neuropathic after the initial examination underwent EMG and NCV testing. This paper is a report of the findings of only those patients with lower extremity signs and symptoms; the upper extremity study is in process.

All needle EMG-NCV studies were performed by a single board-certified electrodiagnostician in a climate-
controlled environment in our clinic. Both studies were performed on the same day, and interpretation of the studies followed the guidelines proposed by Bromberg and Brownell.1

Results

EMG-NCV findings revealed the following: Of the 208 patients, 10% had isolated sensorimotor peripheral neuropathy (PN), 40% had isolated radiculopathy (RAD), 46% had both RAD and PN, and 4% had neither condition (Table 2). There was no difference in the severity of symptoms in patients with PN alone (mild, moderate, or severe) and in those with combined PN and RAD. Muscle denervation was present in half of the patients with RAD alone and in a third of the patients with isolated PN (P<0.05).

One or more toxic conditions were identified in 61% of the 117 patients with PN. Diabetes or elevated HbA1C was present in 22% of patients, and other toxic conditions were found in 39% of patients, the most common being cancer with chemotherapy (14%) and medications reported to be neurotoxic (17%). In an additional 31 patients (26%), a toxin was not identified in the patient’s history but a “toxic-metabolic” condition was diagnosed by EMG-NCV (Table 3).

When PN was present (117 patients) the following nerve involvement was noted: tibial 80%, peroneal 82%, and sural 66%.  All 3 nerves were involved in 40% of the PN patients (Table 4). Superficial saphenous nerves were also studied but involvement was rare (only 5 patients).

Based on the initial examination (prior to EMG-NCV testing), the presence and type of neuropathy was correctly identified in only 51% of patients. When RAD alone was documented, the diagnoses were correct 70% of the time. With PN alone or with RAD, the accuracy was 40% and 45%, respectively. None of the 8 patients with a completely normal EMG-NCV had an accurate diagnosis (Table 5).

Discussion

All patients in our facility had a complete chiropractic and medical evaluation at their screening evaluation. When neuropathy was suspected, a subsequent evaluation included an assessment of the patient’s Michigan Neuropathy Score,7 a detailed assessment of sensory and motor changes in the extremities, and extensive testing of vibratory sensation and reflexes.8,9

We also performed a peripheral vascular examination, including ankle/brachial index and duplex examination (Doppler and echo) when arterial insufficiency was suspected. We did not use the monofilament test. We have, however, added an assessment of skin temperatures at the proximal calf, mid-calf, and dorsum of the foot because skin temperature drops with normal arterial scans are common in neuropathy.10

Traditionally, the role of EDX (EMG-NCV studies) in peripheral neuropathy evaluation has been to characterize the neuropathy in terms of distribution, severity, and chronicity.2-4 Because we had initiated a neuropathy treatment program in our clinic in 2011, we used the results of the EMG-NCV to enroll our patients in our comprehensive treatment program, which included:  

  • Dietary evaluation and modification, especially in patients with diabetes, since excellent glycemic control is known to improve the symptoms of neuropathy11,12  
  • Removal of medications that have been reported to be neurotoxic (especially statins) from the patients’ diets and environments13-17
  • Addition of supplements known to affect nerve health, including potent antioxidants, magnesium, vitamin D, B complex vitamins, lipid soluble allithiamine, acetyl-L-carnitine, and coenzme (Co)Q1018-21
  • Treatment with the ReBuilder electrical system, which had extremely promising results in a convenience study of 551 patients performed by our clinic; in this convenience study, both quality of life and reduction in pain score were significantly improved within 30 days using the ReBuilder electrical system at home6

For patients with radiculopathy, our chiropractic treatment program included manual and/or activator-assisted realignment, decompression treatment, physical therapy using the Pettibon system (emphasis on spine and posture correction, nutrition, and muscular development),22 and self-care training to maintain alignment. We also incorporated judicious use of local anesthetic/botanical anti-inflammatory trigger-point injections.23 During the treatment program, the importance of hydration was repeatedly emphasized to the patients.

Diabetes and PN

The results of the study were surprising in many respects. First, although diabetes is considered to be the leading cause of PN in the United States, and indeed most of the references cited herein refer to diabetic peripheral neuropathy (DPN), we identified diabetes or elevated HbA1C levels in only 22% of our patients with EDX-proven PN. In 51% of patients, a potentially toxic medication was either identified in the patient’s history or suspected by the EMG-NCV findings. Thus, although every diabetic patient should be carefully evaluated for DPN, neuropathy may not be caused by his or her diabetes. A high index of suspicion must be maintained for other neuropathy-causing toxins or conditions, including antidepressants, anticonvulsants, atypical antipsychotic medications, statin therapy, drugs used to treat neuropathy themselves, morbid obesity, and metabolic syndrome.13-17

Although many of our patients were undoubtedly prediabetic, the incidence of other toxic conditions was clearly much greater than was the incidence of diabetes. We do not downplay the importance of diabetes in producing nerve damage. Furthermore, the current obesity and diabetes crisis in America will certainly lead to many more cases of type 2 diabetes and, therefore, a higher incidence and prevalence of DPN.24,25

 The diet we recommend to all of our patients is low in refined carbohydrate and free of processed foods, as are most healthy diet formulations today. The supplements we recommend are initiated immediately after diagnosis. Although some patients cannot afford the more expensive supplements (acetyl-L-carnitine, CoQ10, allithiamine), all patients are started on a multivitamin high in B-complexes, a potent antioxidant like omega-3 ethyl esters or its equivalent, and magnesium and vitamin D. We have noticed return of absent foot reflexes in as little as 4 weeks of treatment with these supplements.

Statins, PN, and Diabetes

The role of statin medications in the development of PN is controversial, and physicians need to weigh the risks versus the benefits of these medications. According to the literature, there have been case reports of patients developing PN while on long-term stain therapy.14,15 A review of the literature reported that the “risk of PN associated with statin use may exist; however, the risk appears to be minimal. On the other hand, the benefits of statins are firmly established.”16 The American College of Cardiology recently recommended the use of statins in virtually all patients with any cardiac risk factors.26

There also is increasing evidence that statins may increase the incidence of type 2 diabetes.27,28 There are now new and expensive drugs being tested in “statin-intolerant” patients, and some patients are being encouraged to “exercise through their leg cramps” rather than stop their statin medications. Of considerable note, many of our neuropathy patients have already discontinued their statins, having heard on television or elsewhere that statins are “dangerous.” At the present time, we discontinue statins in our PN patients with low cardiac risk profiles (with their referring physician’s approval) until more definitive evidence is available concerning statin-induced neuropathy.

Tibial and Peroneal Nerves Most Often Involved

Another finding of clinical significance in our study was that the nerves most often involved with PN were tibial (80%) and peroneal (82%). Sural nerve involvement was observed in only 66% of patients. Therefore, point-of-care NCV testing, which often examines only the sural nerve, would have missed the neuropathy in fully a third of our patients. The earliest publication on point-of-care testing was that of Perkins et al in 2006.29 As of 2015, however, “automated nerve conduction tests or portable hand-held non-invasive nerve conduction studies…are experimental or investigational because there is insufficient scientific data to permit conclusions regarding the effectiveness of these nerve conduction tests compared to conventional electrodiagnostic testing.”30

The 40% incidence of combined neuropathy and RAD is similar to that suggested by the literature.1-4 Only 10% of our patients had neuropathy alone, and 46% had RAD alone. These findings are of particular importance to us as we initiate treatment for all conditions simultaneously. Muscle denervation was more common with RAD than with sensorimotor neuropathy (50% vs 33%, P<0.05), but we did not find a significant difference in the severity of the neuropathy with or without radiculopathic involvement. These findings require further investigation, but may be explained by the fact that symptoms often lessen when denervation occurs and the involved extremity(ies) becomes insensate.

Inaccuracy of Clinical Diagnoses

To us, the single most important finding in this series was the inaccuracy of clinical diagnosis(es) at the initial screening by 2 examining physicians. The overall diagnostic accuracy was only 51%! Even with isolated RAD, the accuracy was only 70% despite that fact that our clinic is largely based on chiropractic medicine. Interestingly, all 8 of the patients with a normal EMG-NCV study had been diagnosed with PN or RAD, and the indication for ordering the study was not evident from reviewing these records. The most common misdiagnoses in all patients were myositis and myalgia.

We are convinced that broader application of needle EMG and NCV testing will result in better diagnosis and treatment as well as reduce costs. All major health care payers include neuropathies and radiculopathies in their indications for EMG-NCV testing and reimburse for 2 studies yearly when the proper indications are present.30 The American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) states that “it is in the best interest of patients for the needle EMG and NCS (nerve conduction study) to be performed and interpreted at the same time.”31

We believe that EDX is underutilized and encourage broader application so that earlier diagnosis and treatment can be undertaken. Unfortunately, even in large urban centers like ours (the greater Chicago area), the availability of EMG-NCV studies is limited. There are only 2 free standing full-time EDX centers outside of our major medical centers. They are inconveniently located. Small wellness centers and chiropractic practices often utilize traveling electrodiagnosticians who visit their facilities weekly, at best, and often only once a month. Quality control of these traveling EMG-NCV technicians is difficult to determine.

Surely, since this test is the gold standard of diagnosis for both RAD and neuropathy, this test should be as readily available as CT scans and MRIs. Our data suggest that those costly tests are unnecessary in the initial evaluation of these conditions and should probably be reserved for those situations in which the patient will likely require a surgical intervention. Stated another way, the EMG-NCV test is the equivalent of the stress test in cardiovascular medicine in that it provides the physiologic information upon which the clinician can determine what treatment is indicated.

Treatment Options

Many studies now suggest that electrical therapy is of benefit in treating neuropathy,6,32-36 and currently there is an ongoing National Institutes of Health-funded study using the Scrambler electrical device.37,38 None of the studies, however, have used baseline and follow-up EMG to document whether there was an improvement of symptoms or in nerve conduction velocity and nerve healing. In our study, the encouraging results of the ReBuilder led to the obvious question of whether our protocol could be of benefit in not only treating neuropathy but also delaying its progression or even preventing its occurrence.6 If so, many patients (patients with diabetes and those on neurotoxic chemotherapy, for example) should be treated proactively.  

Finally, no discussion of neuropathy today would be complete without a look at the role of cannabinoids in treating PN. In a meta-analysis of individual patient data, inhaled cannabis provided short-term relief in only 15% to 20% of patients.39 In contrast, a recent review of randomized controlled studies demonstrated that cannabis was superior to placebo in reduction of pain intensity and in achieving at least a 30% reduction in pain intensity (7 studies with over 1,000 participants).40 Promising studies are appearing in the scientific literature every week. We recently incorporated the use of medical marijuana in our treatment program in Illinois and plan a follow-up study, complete with EDX documentation of our results. We also challenge the academic community to further explore the use of electrotherapy (and cannabinoids) in a rigorous fashion both experimentally and clinically.

Last updated on: November 10, 2016
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Application of Acupuncture to Treat Low Back Pain

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