fibromyalgia

Medical marijuana in fibromyalgia: molecular mechanisms and small randomized controlled trials

Virginia Thornley, M.D., Neurologist, Epileptologist

@VThornleyMD

June 17, 2018

Introduction

Fibromyalgia used to be  a condition denoting excessive pain and was previously questionable as there was no testing that could prove or disprove it. Now, the current thought is that it is attributed to hypersensitivity of the nervous system to pain impulses resulting in multiple points of pain in the body.

Endocannabinoid system in pain modulation

The endocannabinoid system is a major chemical neurotransmitter system that has only come to light as to physiology in the last 20 years. The CB1 receptor is found predominantly in the nervous system on which the endogenous endocannabinoid anandamide exerts its effects. The CB2 receptor is found mostly in the immune system on which 2-Arachidonoylglycerol acts. In the nervous system, cannabinoid receptors are seen in the periaqueductal gray area, ventromedial medulla and dorsal horn of the spinal cord which are areas where pain transmission takes place. This suggests that endocannabinoids play a major role in modulation of pain and can impact pain control through manipulation of this system.

Anandamide and and 2-Arachidonoylglycerol are synthesized on demand. It is released immediately after production. 2-AG is formed from a 2 step process. Anandamide has a low affinity to the TPRV1 receptor (2).

1,2-diacylglycerol (DAG) is  a precursor or 2-AG which is formed by hydrolysis of membrane phosphoinositides. DAG is hydrolyzed by 2-AG hydrolase to form 2-AG. 2-AG may be stimulated by activation of G protein receptor such as glutamate receptors. It activates both CB1 and CB2 receptors. Cannabidiol which is found in the cannabis sativa plant is a natural mimetic of 2-AG. Endogenous 2-AG is found 170 times more than Anandamide in the brain. Exogenous 2-AG suppresses nociceptive stimulus (2). 2-AG activity is potentiated with natural 2-acylglycerols which enhances the effects which does not happen when used alone. This is an entourage effect found in the brain where the combination of substances give a combined resulting effect which does not occur if used alone (2).

Mechanisms in pain modulation

Cannabinoids were found to reduce nociceptive transmission at the level of the pain c-fiber responses in the spinal dorsal horn.

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Randomized controlled trial in fibromyalgia

In one study of 40 patients in a randomized controlled clinical trial, nabilone which is a synthetic cannabinoid was given over a 4 week period. Measures that were evaluated included the visual analog scale for primary outcome and for secondary outcome measure, tender points, secondary outcome measure, Fibromyalgia Impact Questionnaire (FIQ) at weeks 2 and 4 were used. There was statistical difference in treated vs. control groups for pain (P value< 0.02), anxiety (P<0.02 and FIQ (P<0.02). There were more side effects for the treated cohort compared tot he placebo controlled group. This study demonstrates that cannabinoids may be an effective treatment for fibromyalgia (1).

In one paper that reviewed 18 randomized controlled clinical trials of cannabinoids in chronic pain syndromes including fibromyalgia, cannabinoids were found to be an effective type of treatment. Despite the short duration of the trials, pain relief was effective and mild to moderate adverse effects were noted. Larger clinical trials are needed (2).

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  1. Skrabek, et al, “Nabilone for the treatment of pain in fibromyalgia,” J. Pain, 2008, Feb., (9)2:164:173
  2. Lynch, et al, “Cannabinoids for treatment of chronic non-cancer pain: a systemic review of randomized trials,” Br. J. Pharmacology, 2011, Nov., 72(5):735-744
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stem cell

Mesenchymal stem cell therapy: a viable non-surgical option in lower back pain treatment

Virginia Thornley, M.D., Neurologist, Epileptologist

June 9, 2018

Introduction

Back pain is one of the most common pain disorders encountered by neurologists, neurosurgeons, orthopedic surgeons and pain specialists in the out-patient setting. It is not uncommon for patients to go through an extensive list of medications, steroid injections, physical therapy and even surgery and still remain in unrelenting pain. There is a growing interest in alternative treatments especially with the opioid crisis looming and restriction of strong pain medications. This seeks to review scientific mechanisms behind the success in stem cell treatment. It recaps clinical data. Despite a scarcity of published huge randomized clinical trials, there is a growing and clamoring need for alternative treatments such as stem cell therapy for patients desperately trying to find alleviation from their pain. Trailblazing physicians are using this treatment option in real life practice with growing results.
Back pain is a very common disorder which is especially prevalent in the elderly after wear and tear of long-term activity in conjunction with the natural degenerative changes that come with the aging process. Normally the intervertebral disc complex can withstand compression and shear forces because of the proteoglycans that bind water molecules. This becomes lost with aging. In degenerative disc disease, there are pro-inflammatory molecules.

Pathogenesis of degenerative disc disease
Within the nucleus pulposus, there is no vascular supply except at the end neural plate, has no nerves and is prone to damage. The nucleus pulposus relies on glycolysis for effective disposal of waste products through the endplates. After decades, the nucleus pulposus no longer has notochordal features and is replaced by small chondrocyte like cells. There is replacement of the collagen type 1 and collagen type 2 loss eventually replaced with fibrocartilaginous material. Eventually with time, the endplates have calcification of the small pores where molecules diffuse (1).

 

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There are anabolic processes involved as well as catabolic processes including involvement of enzymes, inflammatory mediators, proteinases, aggrecanases. Examples include IL-1 and TNF-alpha. because the disc is avascular this creates an environement of poor regenerative responses with harsh conditions (3).

Some patients may have a genetic predisposition to have flawed extracellular matrix where degenerative disc disease may occur more severely than in other people. Cleavage of proteoglycan can occur with enzymes resulting in loss of height and less ability to reduce compressive and shearing forces. In addition, environmental factors including occupational activities, excessive physical activity impacting the spine may contribute towards degenerative disc disease (1).

Alternative treatment: stem cell therapy
In order to address these issues, various treatments have arisen to try to try to halt the cascade leading to degenerative disc disease. This includes implantation of biomolecules to reduce the catabolic process.

 

 

Stem cell research is gaining more traction as a viable alternative for treatment of this debilitating condition. One study looked at the potential of nucleus pulposus-like cells derived from mesenchymal cells in the rabbit model. From these cells, SOX9, ACAN, COL2, FOXF1, and KRT19 genes were expressed(2). Transplanted nucleus pulposus cells were integrated into the intervertebral disc complex. Improved water content, glycosaminoglycan, and cellularity within the complex was noted. There was a suggestion of biosynthesis with the gene expression of SOX9, ACAn, COL4 (2). This animal study demonstrates that there may be value in nucleus pulposus cells derived from mesenchymal cells may lead to clinical studies where stem cells can be used for back pain.

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Injection of mesenchymal stem cells
Injections of mesenchymal stems cells into the disc may reduce the clinical pain and restore disc tissue loss. It may be able to reduce the catabolic microenvirnment (3)

Clinical studies of stem cell use in humans
It appears that stems cells of mesenchymal type derived from adipose or the umbilicus may have the most promise (4).

In one small study of 10 patients, autologous bone marrow mesenchymal cells were were injected in the nucleosus pulposus and followed for a year. After 3 months, there was improvement of pain and disability of 85% of the maximum. After 12 months, there was still high water content within the nucleosus pulposus (5).

Stem cell effects were studied in 2 patients with back pain and leg numbness. Marrow fluid was obtained autologously from the ilium from each patient. Mesenchymal stem cells were cultured in autogenous serum. Fenestration was performed and collagen sponge was applied percutaneously to the affected intervertebral disc complex. After 2 years, the T2 signal was high showing increased disc content in the grafted discs. Clinical symptoms were ameliorated (6).

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Clinical trials
In an open label trial of 26 patients, using the VAS and Oswestbry disability scale, there was reduced pain after percutaneous injection of bone marrow cell concentrate showing autologous mesenchymal stem cells are a viable alternative treatment for back pain (7). They studied the patients through 12 months. Those who received >2000 colony forming fibroblast units/ml had faster and greater pain reduction.

There is one small randomized controlled clinical trial in 24 patients using the Pfirrmann grading scale for degeneration, allogeneic mesenchymal cells were transferred to the clinical cohort. Significant relief of pain was noted compared to the sham group demonstrating that allogeneic transfer may be logistically better than autogenous transfer (8).

 

Possible adverse effects
Concerns include transformation into neoplastic process. This seems to be true with embryonic stem cells which are much earlier seen in the cell lineage. Mesenchymal cells are further down the line as a committed cell type to obviate this. With in vitro culturing, there is concern for cell mutations, but this is less of a concern if it is a same day procedure, autologous and exist as when they were in the body previously. There is concern for extravasation beyond the limit of the disc and if combined with other treatments such as PRP it may promote osteogenesis. In addition, animal models may not replicate the harsh microenvironments of disc pathology where continual torsion and pressure is involved and effects and outcomes might be different (3).

In summary
There is much scientific and animal model data that stem cells remain a viable option for treatment of back pain which is one of the most common problem encountered by neurologists, neurosurgeons, orthopedic surgeons and pain management specialists. While there is much demonstrated in animal studies, clinical trials are still very sparse. This treatment, however, shows promise and despite paucity of clinical trial data, this treatment is gaining traction in practicing clinicians who treat back pain.

Given the failure with medications and even with surgery there is increased interest in alternative treatments including stem cell therapy.

Introduction/Disclaimer

Introduction/Disclaimer

References

1. Rosenberg, et al, “Bedside to bench and back to bedside: translational implications of targeted intervertebral disc therapeutics,” J. Orthop. Translat., 2017, Apr., 10:18-27.
2. Perez-Cruet, et al, “Potential of human nucleus pulposus-like cells derived from umbilical cord to treat degenerative disc disease,” Neurosurgery, 2018, Feb., doi:10.1093/neuros/nyy012
3. Zeckser, et al, “Multipotent stem cell treatment for discogenic low back pain and disc degeneration,” Stem Cell Int., 2016, doi: 10.1155/2016/3908389
4. Knezevic, et al, “Treatment of chronic low back pain – new approaches on the horizon,” J. Pain Res., 2017, May 10, 10:1111-1123
5. Orozco, et al, “Intervertebral dis repair by autologous mesenchymal bone marrow cells: a pilot study,” Transplantation, 2011, Oct., 15, 92 (7):822-8
6. Yoshikawa, et al, “Disc regeneration therapy using marrow mesenchymal cell transplantation: a report of 2 cases,” Spine, 2010, May 15, 35 (11):E475-80
7. Pettiness, et al, “Percutaneous bone cell concentrate reduces discigenic lumbar pain through 12 months,” Stem Cell, 2015, 33(1):146-156
8. Noriega, et al, “Intervertebral disc repair by allogeneic mesenchymal bone marrow cells,” Transplantation, Aug., 2017, 101(8):1945-1951.

 

 

 

 

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medical marijuana

Cannabinoids and effects on other organ systems: cardiomyocytes and the gastrointestinal system

Virginia Thornley, M.D., Neurologist, Epileptologist

@VThornleyMD

May 8, 2018

Introduction

Cannabinoids are being more and more widely used in a variety of neurological conditions. This always leads to the questions of side effects and will it interacts with other medications? Because this is wholly unchartered territory,  in order to answer these questions, it is necessary to understand the underlying mechanisms.

Cannabinoids can cause tachycardia

Phytocannabinoids, when ingested, can induce tachycardia. The metabolism of cannabinoids by cardiomyocytes likely impacts the side effects elicited in cardiac cells. CYP2J2 is the most significant cytochrome p450 which metabolizes endocannabinoid anandamide (AE) into the cardioprotective epoxides. 6 phytocannabinoids were studied in one paper including delta-9-tetrahydrocannabinol, cannabinol, cannabidiol, cannabigerol, and cannabichromene. These were found to be metabolized more quickly compared to anandamide. The cannabinoids may potentially inhibit the metabolism of anandamide by CYPJ2 such that its effects are still circulating in the system. The most significant inhibition was from delta-9-tetrahydrocannabinol. It follows a non-competitive inhibition model such that the cardioprotective epoxides are not formed as abundantly as they should by the cytochrome p450 CYP2J2 (1).

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The cytochrome P450 system has a significant impact on the metabolism of cannabinoids. Tetrahydrocannabinol is metabolized by CYP2C19 and CYP3A4. cannabinol is metabolized by CYP2C9 and CYP3A4. Synthetic cannabinoids include JWH-018 which is metabolized by CYP1A2 and CYP2C9 and AMC2201 which is metabolized by CYP1A2 and CYP2C9.

The cytochrome P450 enzymes are also thought to be involved in the metabolism of tetrahydrocannabinol. CYP2C9 greatly influences the metabolism of tetrahydrocannabinol. Cytochrome P450 3A4 is important in the metabolism of THC and CBD (2).

Cannabinoids in relation to hyperemesis syndrome

Once abdominal pain has been explored regarding medical etiologies, and there is a presence of 1-year history of cannabis use usually weekly, this diagnosis comes to mind. It usually involves cyclical vomiting associated with nausea. The mechanism is thought to be related to dysregulation by the endocannabinoid pathway in relation to the gastrointestinal tract. The CB1 receptor by which THC or tetrahydrocannabinol exerts it actions is also present in the GI tract. Exogenous cannabinoids may dysregulate the normal endocannabinoid pathway thereby affecting the GI tract through the down-regulation of the normal CB1 receptors so that it is no longer sensitive to endocannabinoids which regulate the system. This results in a dysfunction of the GI tract clinically manifested as cyclical nausea and vomiting. A disruption of the cannabinoid receptors may occur resulting in slowed motility of the gut. Relief can occur with use of hot water which influences the TRPV receptor a G-related coupled protein

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Introduction/Disclaimer

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References

  1. Arnold, et al, “Cross-talk of cannabinoid and endocannabinoid metabolism is mediated via human cardiac CYP2J2,” J. Inorganic. Biochem., 2018, Apr., 7(184):88-99 doi: 10.1016/j.jinorgbio.2018.03.016. (Epub ahead of print)
  2. Stout, et al, “Exogenous cannabinoids as substrates, inhibitors, and inducers of human drug metabolizing enzymes: a systematic review,” Drug Metab. Rev., 2014, Feb., 46(10:86-95.
  3. Lapoint, et al, “Cannabinoid hyperemesis syndrome: public health implications and a novel model treatment guideline,” West J Emerg Med, 2018, Mar., 19(2):380-386.

 

 

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schizophrenia

Cannabidiol may treat psychosis while tetrahydrocannabinol can induce schizophrenia in those susceptible  

Virginia Thornley, M.D., Neurologist, Epileptologist

@VThornleyMD

May 6, 2018

Introduction

There is a well-known correlation of use of cannabis whether it is medical or recreational to the onset of schizophrenia. It unclear if this could be to a direct correlation and disinhibition of the genetic component or the behavior of using it is a prodrome leading up to schizophrenia. This review seeks to elucidate the mechanisms in the correlation of the use of cannabis and onset of schizophrenia.

Mechanisms related to the underlying genetic composition

Schizophrenia may be linked when some of the normal pathways become disrupted with an introduction of THC.  There are 4 genes that were described after a lifetime use of cannabis including KCNT2 which were THC responsive, NCAM1 and CADM2 are significant in functioning in post-synapse. With THC in the system, there are more post-synaptic density genes (1).

Mechanisms related to other neurotransmitter pathways influenced by cannabinoids

In one study, because of the alarming rate of potent synthetic cannabis used recreationally which was found to leave long-lasting schizophrenia disorder in recreational users, this has accelerated research into the pathophysiology. Because cannabinoids work on the CB1 receptor, it is likely that it plays a modulatory role on the other neurotransmitters that can give rise to schizophrenia including dopaminergic, glutamatergic and serotonergic pathways. These pathways are well-established as playing a role in a pro-psychotic state. High efficacy synthetic cannabinoids which are manufactured for recreational purposes are highly more potent compared to natural organic cannabinoids and there is an alarming increase in the correlation of schizophrenia in these users (2).

In one study it is thought to be due to the hypofunctioning of the glutamate system which is directly affected by THC. Exposure to tetrahydrocannabinol appears to reduce the activity at the level of the glutamate receptor as well as deregulate genes for synaptic function(1).

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Susceptibility is related to the development of schizophrenia

In one animal model, the set-up tried to mimic a more real state seen where not all adolescents exposed to synthetic cannabinoids react by developing schizophrenia, there are some studies where all animals develop schizophrenia with exposure. In this animal model, they provided a model that resembles the human model more closely and found that exposure to synthetic cannabinoids in schizophrenia-prone animals caused hyperfunctioning of dopaminergic pathways compared to the control group who were not susceptible at the same dosages. There may be underlying genetic or environmental factors that cause certain individuals to become more prone (2).

THC can cause anxiety and behavioral disorders but can be prevented with CBD

In one animal study, it was found in a rat study that THC can induce anxiety and behavioral disorders. With THC  administration object recognition was impaired in adolescent rates. The studies support effect on the developing brain in relation to cognitive impairment in the animal model. In addition, when rats were exposed to THC there was increased marble burying behavior which in scientific research is thought to signify anxiety or obsessive-compulsive type behavior usually ameliorated with serotonin reuptake inhibitors or benzodiazepines(4).

It was found, however, that a combination of CBD and THC or cannabidiol alone was administered, these behaviors were not produced or produced only minimally. The thought is that CBD is an allosteric competitive inhibitor at the CB1 receptor so that one sees less of the toxic undesirable effects of THC if administered alone (4).

Cannabinoids have a similar profile to atypical anti-psychotics and may be a possible adjunctive treatment in the treatment of psychotic events (5).

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In summary

There is historical evidence that exposure to THC can give rise to schizophrenia in those individuals that are susceptible accounting for the fact that it does not happen to everybody exposed to it. This is related to its influence on serotonergic, dopaminergic and glutamate pathways. THC can induce anxiety, repetitive behaviors which are ameliorated by CBD. CBD may be a useful adjunctive treatment for psychotic disorders. However, the elucidated mechanisms are based on scientific research based on animal models which may not translate into humans.

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Introduction/Disclaimer

https://neurologybuzz.com/

 

References

  1. Guennewig, et al, “THC exposure of human iPSC neurons impacts genes associated with neuropsychiatric disorder,” Transl. Psychiatry, 2018, Apr., 8(1):89.
  2. Fantegrossi, et al, “Pro-psychotic effects of synthetic cannabinoids: interactions with central dopamine, serotonin and glutamate systems, Drug Metab. Review, 2018, Jan, 50(1)
  3. Aguilar, et al, “Adolescent synthetic cannabinoid exposure produces enduring changes in dopamine neuron activity in the rodent model of schizophrenia,” Int. J. Neurpsychopharmacol., 2018, Apr., 31 (4):393-403.
  4. Murphy, et al, “Chronic adolescent delta9-tetrahydrocannabinol treatment of male mice leads to long-term cognitive behavioral dysfunction which is prevented by concurrent cannabidiol treatment,” Cannabis Cannabinoid Res., 2017, 2(1):235-246.
  5. Deiana, et al, “Medical use of cannabis: a new light for schizophrenia?” Drug Test Analysis, 2013, Jan., (5)1:46-51
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