Category Archives: Neuropathic Pain

The Major Brain Endocannabinoid 2-AG Controls Neuropathic Pain and Mechanical Hyperalgesia in Patients with Neuromyelitis Optica.

Posted on by
Reply

“Recurrent myelitis is one of the predominant characteristics in patients with neuromyelitis optica (NMO). While paresis, visual loss, sensory deficits, and bladder dysfunction are well known symptoms in NMO patients, pain has been recognized only recently as another key symptom of the disease. Although spinal cord inflammation is a defining aspect of neuromyelitis, there is an almost complete lack of data on altered somatosensory function, including pain. Therefore, eleven consecutive patients with NMO were investigated regarding the presence and clinical characteristics of pain. All patients were examined clinically as well as by Quantitative Sensory Testing (QST) following the protocol of the German Research Network on Neuropathic Pain (DFNS). Additionally, plasma endocannabinoid levels and signs of chronic stress and depression were determined. Almost all patients (10/11) suffered from NMO-associated neuropathic pain for the last three months, and 8 out of 11 patients indicated relevant pain at the time of examination. Symptoms of neuropathic pain were reported in the vast majority of patients with NMO. Psychological testing revealed signs of marked depression. Compared to age and gender-matched healthy controls, QST revealed pronounced mechanical and thermal sensory loss, strongly correlated to ongoing pain suggesting the presence of deafferentation-induced neuropathic pain. Thermal hyperalgesia correlated to MRI-verified signs of spinal cord lesion. Heat hyperalgesia was highly correlated to the time since last relapse of NMO. Patients with NMO exhibited significant mechanical and thermal dysesthesia, namely dynamic mechanical allodynia and paradoxical heat sensation. Moreover, they presented frequently with either abnormal mechanical hypoalgesia or hyperalgesia, which depended significantly on plasma levels of the endogenous cannabinoid 2-arachidonoylglycerole (2-AG). These data emphasize the high prevalence of neuropathic pain and hyperalgesia in patients with NMO. The degree of mechanical hyperalgesia reflecting central sensitization of nociceptive pathways seems to be controlled by the major brain endocannabinoid 2-AG.”

http://www.ncbi.nlm.nih.gov/pubmed/23951176

Activation of spinal cannabinoid cb2 receptors inhibits neuropathic pain in streptozotocin-induced diabetic mice.

Posted on by
Reply

“The role of spinal cannabinoid systems in neuropathic pain of streptozotocin-induced diabetic mice was studied…

 … A low dose of WIN-55,212-2  significantly recovered the tail-flick latency in streptozotocin-induced diabetic mice… The selective cannabinoid CB2 receptor agonist L-759,656 also dose-dependently recovered the tail-flick latency in streptozotocin-induced diabetic mice…

 These results indicate that spinal cannabinoid systems are changed in diabetic mice and suggest that cannabinoid CB2 receptor agonists might have an ability to recover diabetic neuropathic pain.”

http://www.ncbi.nlm.nih.gov/pubmed/23892011

Anandamide deficiency and heightened neuropathic pain in aged mice.

Posted on by
Reply

“Damaging of peripheral nerves may result in chronic neuropathic pain for which the likelihood is increased in the elderly. We assessed in mice if age-dependent alterations of endocannabinoids contributed to the heightened vulnerability to neuropathic pain at old age.

We assessed nociception, endocannabinoids and the therapeutic efficacy of R-flurbiprofen in young and aged mice in the spared nerve injury model of neuropathic pain.

 R-flurbiprofen was used because it is able to reduce neuropathic pain in young mice in part by increasing anandamide.

Aged mice developed stronger nociceptive hypersensitivity after sciatic nerve injury than young mice.

This was associated with low anandamide levels in the dorsal root ganglia, spinal cord, thalamus and cortex, which further decreased after nerve injury…”

 More: http://www.ncbi.nlm.nih.gov/pubmed/23597506

[Marihuana and cannobinoids as medicaments].

Posted on by
Reply

“Biological activity of cannabinoids is caused by binding to two cannabinoid receptors CB1 and CB2. Psychoactive is not only tetrahydrocannabinol (THC) but also: cannabidiol, cannabigerol or cannabichromen.

Formerly, the usefulness of hemp was assessed in the relation to temporary appeasement of the symptoms of some ailments as nausea or vomiting.

Present discoveries indicates that cannabis-based drugs has shown ability to alleviate of autoimmunological disorders such as: Multiple sclerosis (MS), Rheumatoid arthritis (RA) or inflammatory bowel disease.

Another studies indicates that cannabinoids play role in treatment of neurological disorders like Alzheimer disease or Amyotrophic lateral sclerosis (ALS) or even can reduce spreading of tumor cells.

Cannabinoids stand out high safety profile considering acute toxicity, it is low possibility of deadly overdosing and side-effects are comprise in range of tolerated side-effects of other medications.

In some countries marinol and nabilone are used as anti vomiting and nausea drug. First cannabis-based drug containg naturally occurring cannabinoids is Sativex. Sativex is delivered in an mucosal spray for patients suffering from spasticity in MS, pain relevant with cancer and neuropathic pain of various origin.

Cannabis side-effects varies and depend from several factors like administrated dose, rout of administration and present state of mind. After sudden break from long-lasting use, withdrawal symptoms can appear, although they entirely disappear after a week or two.”

http://www.ncbi.nlm.nih.gov/pubmed/23421098

Emerging role of the cannabinoid receptor CB2 in immune regulation: therapeutic prospects for neuroinflammation.

Posted on by
Reply

“There is now a large body of data indicating that the cannabinoid receptor type 2 (CB2) is linked to a variety of immune events. This functional relevance appears to be most salient in the course of inflammation, a process during which there is an increased number of receptors that are available for activation. Studies aimed at elucidating signal transduction events resulting from CB2 interaction with its native ligands, and of the role of exogenous cannabinoids in modulating this process, are providing novel insights into the role of CB2 in maintaining a homeostatic immune balance within the host. Furthermore, these studies suggest that the CB2 may serve as a selective molecular target for therapeutic manipulation of untoward immune responses, including those associated with a variety of neuropathies that exhibit a hyperinflammatory component.”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2768535/

Foot Pain Associated With HIV Reduced By Smoked Cannabis In Placebo Trial

Posted on by
Reply

“In a randomized placebo-controlled trial, patients smoking cannabis experienced a 34 percent reduction in intense foot pain associated with HIV- twice the rate experienced by patients who smoked placebo.

“This placebo-controlled clinical trial showed that people with HIV who smoked cannabis had substantially greater pain reduction than those who did not smoke the cannabis,” said study lead author Donald I. Abrams, MD, UCSF professor of clinical medicine.

 “These results provide evidence that there is a measurable medical benefit to smoking cannabis for these patients.”

The results of this first study indicate that cannabis may indeed be useful in the amelioration of a very distressing, disabling, and difficult to treat complication of HIV…”

More: http://www.medicalnewstoday.com/releases/62917.php

Cannabis in painful HIV-associated sensory neuropathy: a randomized placebo-controlled trial.

Posted on by
Reply

“To determine the effect of smoked cannabis on the neuropathic pain of HIV-associated sensory neuropathy and an experimental pain model…  randomized placebo-controlled trial… involving adults with painful HIV-associated sensory neuropathy.

Patients were randomly assigned to smoke either cannabis (3.56% tetrahydrocannabinol) or identical placebo cigarettes with the cannabinoids extracted three times daily for 5 days. Primary outcome measures included ratings of chronic pain and the percentage achieving >30% reduction in pain intensity.

Acute analgesic and anti-hyperalgesic effects of smoked cannabis were assessed using a cutaneous heat stimulation procedure and the heat/capsaicin sensitization model.

RESULTS:

Fifty patients completed the entire trial. Smoked cannabis reduced daily pain by 34% (median reduction; IQR = -71, -16) vs 17% (IQR = -29, 8) with placebo (p = 0.03). Greater than 30% reduction in pain was reported by 52% in the cannabis group and by 24% in the placebo group (p = 0.04).

The first cannabis cigarette reduced chronic pain by a median of 72% vs 15% with placebo (p < 0.001).

Cannabis reduced experimentally induced hyperalgesia to both brush and von Frey hair stimuli (p < or = 0.05) but appeared to have little effect on the painfulness of noxious heat stimulation.

No serious adverse events were reported.

CONCLUSION:

Smoked cannabis was well tolerated and effectively relieved chronic neuropathic pain from HIV-associated sensory neuropathy. The findings are comparable to oral drugs used for chronic neuropathic pain.”

http://www.ncbi.nlm.nih.gov/pubmed/17296917

Medicinal Marijuana Effective For Neuropathic Pain In HIV – MedicalNewsToday

Posted on by
Reply

“In a double-blind, placebo-controlled clinical trial to assess the impact of smoked medical cannabis, or marijuana, on the neuropathic pain associated with HIV, researchers at the University of California, San Diego School of Medicine found that reported pain relief was greater with cannabis than with a placebo. The study, sponsored by the University of California Center for Medical Cannabis Research (CMCR) based at UC San Diego, will be published on line, in the journal Neuropsychopharmacology.

Led by Ronald J. Ellis, M.D., Ph.D., associate professor of neurosciences at UCSD School of Medicine, the study looked at 28 HIV patients with neuropathic pain not adequately controlled by other pain-relievers, including opiates. They took part in the controlled study as outpatients at the UCSD Medical Center. The proportion of subjects achieving pain reduction of 30 percent or more was greater for those smoking cannabis than those smoking the placebo.

“Neuropathy is a chronic and significant problem in HIV patients as there are few existing treatments that offer adequate pain management to sufferers,” Ellis said. “We found that smoked cannabis was generally well-tolerated and effective when added to the patient’s existing pain medication, resulting in increased pain relief.””

More:  http://www.medicalnewstoday.com/releases/117509.php

Medicinal Marijuana Effective For Neuropathic Pain In HIV, Study Finds – ScienceDaily

Posted on by
Reply

“In a double-blind, placebo-controlled clinical trial to assess the impact of smoked medical cannabis, or marijuana, on the neuropathic pain associated with HIV, researchers at the University of California, San Diego School of Medicine found that reported pain relief was greater with cannabis than with a placebo.

The study’s findings are consistent with and extend other recent research supporting the short-term efficacy of cannabis for neuropathic pain,

“This study adds to a growing body of evidence that indicates that cannabis is effective, in the short-term at least, in the management of neuropathic pain,” commented Igor Grant, M.D., professor of psychiatry and director of the CMCR.

Grant noted that this is the fourth CMCR sponsored study to provide convergent evidence that cannabis can help in relieving these types of pain…”

More: http://www.sciencedaily.com/releases/2008/08/080806113135.htm

Medical Marijuana Might Reduce Nerve Pain Among People Living With HIV/AIDS, Study Says – MedicalNewsToday

Posted on by
Reply

“Medical marijuana might reduce the pain of peripheral neuropathy, a type of nerve damage, among people living with HIV/AIDS, according to a study published in the Feb. 13 issue of the journal Neurology, the Washington Post reports (Weiss, Washington Post, 2/13). Donald Abrams of the University of California-San Francisco and colleagues examined the effects of smoking medicinal marijuana among people living with HIV/AIDS during a two-year period beginning in May 2003, the San Francisco Chronicle reports.

The results are “evidence, using the gold standard for clinical research, that cannabis has some medical benefits for a condition that can be severely debilitating,” Abrams said.”

More:  http://www.medicalnewstoday.com/releases/62955.php