Start watching to learn about nerve pain treatment! Why does neuropathic pain occur? What are alternative treatments? What prescription medications and topical treatments are used? Data on gabapentin and sativex (synthetic marijuana). Peripheral nerve and spinal cord stimulators.
There have been significant advances in knowledge regarding the pathology, etiology, assessment, and treatment of several significant neurogenic pain disorders regularly encountered by neurorehabilitation professionals in both inpatient and outpatient care. In a collection of articles published in NeuroRehabilitation, experts describe the latest advancements in neurogenic classification and pain management and treatment of these disorders.
Neurogenic pain results from injury to or disease of the central and/or peripheral nervous system. Types of neurogenic pain include neuropathic pain (due to nerve damage or disease), central pain (arising from a lesion in the central nervous system – such as thalamic pain following stroke), and deafferentation pain (the interruption or destruction of the afferent connections of nerve cells), among other mechanisms.
“There are multiple emerging trends in neurogenic pain management with particular reference to complex regional pain syndrome (CRPS), neuropathic pain, and cranial neuralgias,” explains Guest Editor and co-Editor-in-Chief Nathan Zasler, MD, Concussion Care Centre of Virginia Ltd. and Tree of Life Services, Inc. Dr. Zasler is also a clinical professor in the Department of Physical Medicine and Rehabilitation at Virginia Commonwealth University in Richmond, VA, USA. “The topic of post-traumatic cephalalgia (headache) remains highly debated as does the area of functional/psychogenic pain disorders, both of which are elaborated on in this thematic issue of NeuroRehabilitation along with other more common, controversial, and/or challenging neurogenic pain disorders.”
Articles in this issue provide in-depth reviews of:
Highlighted contributions in this issue include:
Douglas Murphy, MD, Regional Amputation Center, Central Virginia Veterans Health Center; and Physical Medicine & Rehabilitation, Virginia Commonwealth University Medical Center, Richmond, VA, USA, and colleagues review the epidemiology, classifications, pathology, non-invasive and invasive treatments of peripheral neuropathic pain. Neuropathic pain occurs in up to 10% of the general population and in patients with neck and back pain and diabetes. Chemotherapy can also be associated with the development of painful neuropathies in 19%-85% of cases. Characteristic symptoms are burning, tingling, lightning bolts of pain, sharp sensations, unpleasant cold sensations, and electric-like sensations. Secondary symptoms and problems can include anxiety, depression, sleep disturbances, and impairment of quality of life.
“Peripheral neuropathic pain has a cost to the patient and society in terms of emotional consequences, quality of life, lost wages, and the cost of assistance from the medical system, and thus deserves serious consideration for prevention, treatment, and control,” notes Dr. Murphy. “There is a wide range of pharmacologic options to control this type of pain, and when such measures fail, numerous interventional methods can be employed such as nerve blocks and implanted stimulators. It is an evolving therapeutic arena. Physicians providing these therapies need to use diligent patient selection processes and a multimodal, individualized pain program that supports a strong risk/benefit ratio.”
Brigid Dwyer, MD, Department of Neurology, Boston University, Boston, MA, USA, and Nathan Zasler, MD, review the highly-debated topic of post-traumatic cephalalgias (PTC) or post-traumatic headache. They note that PTC remains controversial on a number of levels and provide an overview and discussion of current classification and limitations, epidemiology, and risk factors for PTC, subtypes of PTC and associated pain generators, as well as pathophysiology.
They contend that the current classification using the International Headache Society’s International Classification of Headache Disorders has significant limitations that warrant reassessment. They also review the clinical course of PTC and prognostic risk factors for pain persistence. The authors discuss clinical management and limitations of the existing literature on PTC, noting that medication overuse may paradoxically exacerbate headache symptoms and prolong recovery times when superimposed upon pre-existing headache pathology.
According to Dr. Dwyer and Dr. Zasler, “A multifactorial diagnostic and treatment approach, cognizant of biopsychosocial factors as well as the unique interplay between central and musculoskeletal pain, sleep, mood, cognition and exertional limitations, continues to be most successful.”
“The most significant challenges are dissemination of new knowledge, in particular practice guidelines, to clinicians in the trenches treating neurogenic pain disorders,” concludes Dr. Zasler. “As guest editor of this issue, I am very grateful to all the contributors and their high quality of work, which will hopefully be appreciated by readers and advance knowledge in this area of neurorehabilitation.”
Richard Barohn, MD, is the lead researcher and executive vice chancellor for health affairs at the University of Missouri Justin Kelley
More than 20 million people in the U.S. suffer neuropathic pain. At least 25% of those cases are classified as unexplained and considered cryptogenic sensory polyneuropathy (CSPN). There is no information to guide a physician’s drug choices to treat CSPN, but a researcher from the University of Missouri School of Medicine and MU Health Care led a first-of-its-kind prospective comparative effectiveness study.
The study compared four drugs with different mechanisms of action in a large group of patients with CSPN to determine which drugs are most useful for this condition. The study involved 40 sites and enrolled 402 patients with diagnosed CSPN who were 30 years or older and reported a pain score of four or greater on a 10-point scale.
Participants were prescribed one of four medications commonly used to treat CSPN: nortriptyline, a tricyclic antidepressant; duloxetine, a serotonin-norepinephrine reuptake inhibitor; pregabalin, an anti-seizure drug; or mexiletine, an anti-arrhythmic medication. Patients took the prescribed treatment for 12 weeks and were evaluated at four, eight and 12 weeks. Any participant who reported at least a 50% reduction in pain was deemed as demonstrating an efficacious result. Patients who discontinued the treatment drug because of adverse effects were also measured.
“This study went beyond whether the drug reduced pain to also focus on adverse effects,” said Richard Barohn, MD, lead researcher and executive vice chancellor for health affairs at the University of Missouri. “As the first study of its kind, we compared these four drugs in a real-life setting to provide physicians with a body of evidence to support the effective management of peripheral neuropathy and to support the need for newer and more effective drugs for neuropathic pain.”
Nortriptyline had the highest efficacious percentage (25%), and the second-lowest quit rate (38%), giving it the highest level of overall utility. Duloxetine had the second-highest efficacious rate (23%), and lowest drop-out rate (37%). Pregbalin had the lowest efficacy rate (15%) and Mexiletene had the highest quit rate (58%).
“There was no clearly superior performing drug in the study,” Barohn said. “However, of the four medications, nortriptyline and duloxetine performed better when efficacy and dropouts were both considered. Therefore, we recommend that either nortriptyline or duloxetine be considered before the other medications we tested.”
There are other nonnarcotic drugs used to treat painful peripheral neuropathy, including gabapentin, venlafaxine and other sodium channel inhibitors. Barohn said additional comparative effectiveness research studies can be performed on those drugs, so doctors can further build a library of data for the treatment of CSPN. His goal is to build effectiveness data on nearly a dozen drugs for CSPN.
UNM researchers have found that hemp oil helps to reduce pain in mice. CREDIT UNM
Researchers examine the effectiveness of consuming hemp oil extracted from the whole Cannabis plant using a chronic neuropathic pain animal model. Researchers at The University of New Mexico (UNM) showed that legal Cannabis hemp oil reduced mechanical pain sensitivity 10-fold for several hours in mice with chronic post-operative neuropathic pain.
Distinguished from its still largely criminally prohibited cousin, “hemp” refers to Cannabis plants with less than 0.3 percent tetrahydrocannabinol (THC) per mass. Hemp is now federally legal to produce and consume in most regions throughout the United States (U.S) as a result of the Hemp Farming Act, proposed by the U.S. Congress and signed into law by President Donald Trump in 2018.
This major breakthrough in cannabis prohibition now enables millions of Americans the ability to access a natural, effective, and relatively safe alternative option for treating chronic pain. Conventional pharmacological drugs, namely opioids, are driving the leading form of preventable deaths and conventional medical errors are the third leading cause of death in the U.S.
The University of New Mexico has conducted a series of recent studies testing the effectiveness and safety of consuming the Cannabis plant, but this is the first study measuring the therapeutic potential of legal hemp oil with low THC levels.
“Cannabis plants with low THC are still psychoactive, but tend to result in less psychedelic experiences, while still offering profound and often immediate relief from symptoms such as pain, anxiety, and depression,” says co-researcher, Dr. Jacob Miguel Vigil, associate professor in the UNM Psychology Department.
Using a chronic neuropathic pain model that exposes mice to post-operative neuropathic pain equivalent to several years of chronic pain in human clinical patients, the researchers were able to examine how hemp oil influences momentary pain sensitivity to the affected region. For several hours after Cannabis consumption the mice demonstrated effective pain relief, approaching the mechanical pain sensitivity of naïve control mice that did not undergo the surgical operation.
“Our lab utilizes a unique nerve injury model mimicking human neuropathic pain that has allowed demonstration of hemp’s reversal of the pain related behavior” said one of the lead investigators, Dr. Karin N. Westlund, Department of Anesthesiology, their article titled “The Therapeutic Effectiveness of Full Spectrum Hemp Oil Using a Chronic Neuropathic Pain Model,” published in the journal Life.
Studies in animals can be superior to clinical trials because they circumvent human biases and expectancy effects, or perceptual and cognitive reactions to enrollment in cannabis-themed experiments. Several studies measuring the effects of cannabis in humans observe patients reporting psychedelic experiences, whether or not they received the active cannabis agent, otherwise referred to as the ‘placebo effect.’
The study examined the effectiveness of “LyFeBaak” hemp oil, produced by Organic-Energetic Solutions, which has been available for legal purchase in New Mexico since 2019. “We grow hemp that is optimized to potentiate the plants utmost health and vitality through hypermineralization techniques, rather than merely plants that are grown in a state of fight-or-flight, which unfortunately is common in the cannabis industry. These techniques have enabled us to produce hemp products that patients swear are effective for treating dozens of mental and physical health conditions. The new changes in hemp laws are now allowing us to test these claims,” adds co-author and hemp grower, Anthony L. Ortiz.
“Hemp plants contain numerous therapeutic constituents that likely contribute to analgesic responses, including terpenes and flavonoids, which in theory, work together like members of a symphony, often described as the entourage effect,” says fellow researcher, Jegason P. Diviant. Several clinical investigations have shown that medications based on synthetic cannabis analogues and isolated compounds tend to offer lower reported symptom relief and a greater number of negative side effects as compared to whole plant, or “full-spectrum” Cannabis flower and plant-based extracts.
The authors do caution that few studies exist on the long-term use of hemp oil, due mostly to historical federal prohibition laws in the U.S. “However, this is an extremely exciting time in modern medical discovery, because the average citizen now has legal access to a completely natural and effective medication that can be easily and cheaply produced, simply by sticking a seed in the ground and caring for it as you would any other important part of your life,” says Vigil.
Meralgia Paresthetica
Welcome to our latest informational post where we look at various different medical conditions and was of managing pain. Today we would like to focus on Meralgia Paraesthetica or “Burning Thigh Pain”. In fact it is a type of neuropathic pain. You can find out more about neuropathic pain at our previous blog here.
Meralgia paraesthetica is numbness or pain in the outer thigh not caused by injury to the thigh itself but rather to a nerve that goes from the thigh to the spinal column.
Typical symptoms often include:
• Pain on the outer side of the thigh. This can go right to the knee.
• A burning sensation, tingling, or numbness in the same area
• Occasionally, aching in the groin area or pain spreading across the buttocks
• People with Meralgia Paresthetica may find themselves hypersensitive to heat!
Management is typically through anti-inflammation products and painkillers. However looser clothes are also recommended. In some cases bed rest may be suggested by your doctor.
In the long term physiotherapy and general weight loss with assist recovery.
As with many of our blogs were we look at particular conditions we are looking for the input of people with that condition. In particular we are interested in exploring the following aspects of Meralgia Paresthetica. It would be great if you could share your experiences in the comments boxes below:-
• When were you diagnosed with Meralgia Paresthetica?
• What were your original symptoms of Meralgia Paresthetica?
• What tests were you given for Meralgia Paresthetica?
• What impact if any has Meralgia Paresthetica had on your lifestyle in particular your choice of clothing?
• If you had one piece of advice for a fellow sufferer what would it be?
Thanks very much for your help in advance!