autism

Medical marijuana: effects on pediatric patients with autism and the developing brain

Virginia Thornley, M.D., Neurologist, Epileptologist

@VThornleyMD

May 6, 2018

Introduction

Medical cannabis is being more and more commonly used in medical conditions specifically neurological. The CB1 receptor is found predominantly within the nervous system and in a few other organs on a lesser basis. The CB2 receptor is mainly in the immune system and found in other organs to a lesser extent.

Recent arguments have arisen promoting medical cannabis in children particularly in those with autism and attention deficit hyperactivity disorder.  It has already been well-established in patients with epilepsy. However, the effects on the developing brains of children have not yet been well-documented as it is not yet widely used or studied in the pediatric population. There are many animal models but this does not always correspond to translate into similar human findings.

Effect in autism in animal models and clinical studies

A current topic of debate is not only using THC in pediatric patients but those with autism. Autism is part of the pervasive developmental disorder consisting of social inhibition and isolation including poor eye contact, delayed language skills, aggressive behavior and may be characterized as having stereotypies such as flapping of the arms. Self-injury, eating and sleep disorders may occur. The etiology may be related to genetic, neurobiochemical or environmental and the exact cause is unclear.

In one animal model study, mice with induced Dravet syndrome-like symptoms was noted to improve in autistic-like social interactions with the addition of low dose cannabidiol (2) of 10mg/kg. At low doses, the DS mice interacted more with stranger mice. At higher doses, this was not noted. Dravet syndrome is a type of epileptic syndrome affecting the SCN1A gene causing medically refractory seizures combined with autism.  However, this was an animal model. Scientific studies do not necessarily translate into positive human clinical results.

There was one case report of a six-year-old boy with early autism. Dronabinol  (delta-9-THC) was administered at 3.62mg a day and followed for 6 months. Using the ABC scale (aberrant behavior checklist), the patient improved in terms of stereotypies which were less, lethargy was reduced, hyperactivity improved, and inappropriate speech improved (4).

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Endocannabinoid system and mechanisms in relation to autism

There are several lines of thinking regarding the role of the endocannabinoid and autism. It is thought that the endocannabinoid system plays a role in neurological development, but can also be modulated by outside cannabinoids. Another line of thinking is that autism spectrum disorders may be related to disrupted pathways that have been affected by the endocannabinoid pathway (5). In one animal study, it was found that the oxytocin peptide may be responsible for disrupting normal signaling pathways giving rise to autism spectrum disorders. Oxytocin appears to be crucial in mediating social reward which is impaired in autistic patients. Anandamide seems to play a role in the signaling pathways for oxytocin which is responsible for the social reward.   Social reward is aberrant in those with autism and this pathway thought to play a key role in causing its pathogenesis. By increasing anandamide at the CB1 receptor, ASD and social impairment is improved (5).

Effect on a fetus

Tetrahydrocannabinol is lipophilic and crosses the blood-brain barrier. It can get stored in the fatty stores which are likely the reason it may have a long-lasting effect.  Cannabinoids have been found to cross the placenta and affect the fetus. It may result in hyperactivity and impulsivity in babies with cannabinoid exposure in utero.

 

Effect on early cerebral development

It was found that in adolescents who used cannabis, there is a reduction in the IQ by the age of 38. It was found that cannabinoid receptors influence axonal migrations as well as subcortical projections within the cerebrum. This affects synaptic connections during childhood and adolescence(3).

The adolescent brain is still not fully matured and likely still subject to neuronal plasticity and changes. It may be affected by substances. One study showed that the frontal lobe is vulnerable to cannabis in adolescents who used it heavily and that cannabis use may impact working memory. (1)

 

 

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During adolescence, when cannabis is initiated it may affect the neuronal circuitry developing in the immature brain. The richest regions in the brain with cannabinoid receptors are the prefrontal cortex, medial temporal lobes, striatum, white matter connections, and cerebellum. When cannabis is introduced during this neurocritically important time of development, these regions can become dysfunctional although some functional studies have shown altered, weakened, strengthened or combination of changes (6).

Some of the most common adverse effects

At high doses in chronic users, it was found to induce anxiety, panic attacks. It can increase blood pressure. However, clinically, it may control seizures

 

In summary

There is a small body of evidence from a scientific standpoint that cannabis may work to help alleviate autism-like symptoms based on the animal models. There is a not enough evidence from a clinical evidence standpoint in human studies to support its use in pediatric patients, with one case report that it helped with impulsivity, reduced lethargy, and inattention. Randomized placebo-controlled clinical trials are needed.

Research has found that cannabinoids may help oxytocin and disrupted signaling pathways that play a role in social reward which is impaired in autism. At present, there is evidence that cannabis may affect neurocognitive development but these are studies in pregnant mothers who used it heavily recreationally and adolescents who used it heavily. It is unclear if there may be a similar impact when used in the pediatric population at a medical dosage and administration as there are not enough studies to expound on this.

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Introduction/Disclaimer

https://neurologybuzz.com/

Reference

  1. Jager, et al, “Cannabis use and memory brain function in adolescent boys: a cross-sectional multicenter fMRI study,” J. Am. Acad. Child Adolesc. Psychiatry, 2010, Jun., 49(6):561-572.
  2. Kaplan, et al, “Cannabidiol attenuates seizures and social deficits in a mouse model in Dravet syndrome,” Proceedings of the National Academy of Science, 2017, Oct.. 114 (42):11229-11234.
  3. Scott, et al, “Medical marijuana: a review of the science and implications for developmental-behavioral pediatric practice,” J. Dev. Behav. Ped., 2016, Feb., 36 (2):115-123.
  4. Kurz, et al, “Use of dronabinol  (delta-9-THC) in autism: a prospective single-case study with early infantile autistic child,” Cannabinoids, 2010, 5 (4):4-6.
  5. Wei, et al, “Enhancement of anandamide-mediated endocannabinoid signaling corrects autism-related social impairment,” Cannabis Cannabinoid Research, 2016, 1(1):81-89
  6. Kelly, et al, “Distinct effects of childhood ADHD and cannabis use on brain functional architecture in young adults, Neuroimage Clin., 2017, 13:188-200.

 

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ADHD

Medical marijuana: effect in pediatric patients with ADHD, long-term cognitive effects in children and review of literature

Virginia Thornley, M.D.,  Neurologist, Epileptologist
May 2, 2018

Introduction
With the advent of a wide use of cannabinoids in neurological disease compared to previous times, attention hyperactivity deficit disorder has arisen as one of the possible disorders where patients may benefit. Because it starts in childhood, questions arise whether it may be applied to the pediatric patients with ADHD. If so, what are the long-term consequences on the developing brain?

Effect of cannabis in ADHD and on the brain
There is a paucity of literature on cannabis use in children with ADHD, most have been on adults.  There are some recent clinical trials and its use in adult patients with ADHD.  In a recent study on ADHD in adults, 30 patients were studied, 15 were in the placebo-controlled group and 15 were given Sativex oromucosal spray (combination CBD:THC). There was no statistical difference in cognitive performance although the score patterns on those on Sativex were higher. There was some improvement in attention. There was a significant improvement in emotional lability and hyperactivity (p=0.3). This implies that cannabinoids may play a role in adult ADHD (1).

In a study of 579 young adult patients with an early history of ADHD of which 129 had to be excluded, it was found that the dorsal attention network found in the parietal region was stronger in those with ADHD. The right fronto-parietal and right inferior frontal region connections were weaker in the ADHD group. The left prefrontal dorsal connections and the right prefrontal cortex connections in ADHD were reduced (2).

One of the key components of ADHD in children is motor dysregulation and weakened connections in the somatosensory region. The stronger connections in ADHD in the frontal-opercular regions suggests compensatory adaptations to maintain normal cognition.  There are stronger right parietal region connections in patients with ADHD possibly suggesting maladaptive mechanisms. When patients with ADHD and cannabis use were studied it appeared that there were neuroadaptive processes. In those who used cannabis, there were stronger intrinsic connections with a superior delayed recall.  There were stronger connections in the left fusiform gyrus that correlated with a) less cognitive interference, these are emotional thoughts or personality traits that can intrude and affect tasks at hand and b) better response inhibition performance, this is the ability to ignore distractions. This is consistent with other studies showing an increased task activation response (2).

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Effect of cannabis on the fetus
Tetrahydrocannabinol is lipophilic and crosses the blood-brain barrier. It can get stored in the fatty stores which are likely the reason it may have a long-lasting effect.  Cannabinoids have been found to cross the placenta and affect the fetus. It may result in hyperactivity and impulsivity in babies with cannabinoid exposure in utero (3). There was a greater incidence of inattention and delinquency in prenatal exposure to cannabis.

Effect of medical marijuana in early cerebral development
It was found that in adolescents who used cannabis, there is a reduction in the IQ by the age of 38. It was found that cannabinoid receptors influence axonal migrations as well as subcortical projections within the cerebrum. This affects synaptic connections during childhood and adolescence(4).

The adolescent brain is still not fully matured and likely still subject to neuronal plasticity and changes. It may be affected by substances. One study showed that the frontal lobe is vulnerable to cannabis in adolescents who used it heavily and that cannabis use may impact working memory (5).

During adolescence, when cannabis is initiated it may affect the neuronal circuitry developing in the immature brain. The richest regions in the brain with cannabinoid receptors are the prefrontal cortex, medial temporal lobes, striatum, white matter connections, and cerebellum. When cannabis is introduced during this neurocritically important time of development, these regions can become dysfunctional although some functional studies have shown altered, weakened, strengthened or combination of changes (2).

Some of the most common adverse effects
At high doses in chronic users, it was found to induce anxiety, panic attacks. It can increase blood pressure. However, clinically, it may control seizures

Discussion
There is a paucity of literature on the effects of medical marijuana on the pediatric population. It has been mostly studied in adult patients. It is difficult to correlate the results of beneficial effects on adults on children since the pediatric brain is still developing. In adult patients with ADHD, apparently exposure to cannabis results in a superior delayed recall, there were fewer thought intrusions when completing tasks and better able to ignore distractions.

When exposed in utero, there was a greater risk of developing inattention, hyperactivity, and impulsivity in children who were exposed before conception. There was a greater tendency towards delinquency. In addition, adolescents who had been chronically exposed to cannabis may have had their working memory impacted. The adolescent period is significant from a neurological standpoint in brain development. There were mixed reports on connections being strengthened, weakened or a combination of the two being reported.

It is difficult to correlate the data of chronic medical cannabis exposure of adolescents in a patient who will use it for its medicinal value since the route, amount and administration and frequency will be completely and distinctly different. In addition, most of the adolescent data has been derived from those who had used it recreationally usually by smoking it heavily, there may be a synthetic component which may be detrimental and it is not clear what other substances may have been added.

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In summary
In short, there is not enough scientific and clinical data to support the use of medical cannabis in pediatric patients. Most of the data is derived from animal studies or studies in adults where there are medical benefits. In the pediatric brain even while studies showed abnormal memory in chronic use it was studied in a very different population of heavy recreational users. Therefore, it is not clear if adult findings can translate into similar pediatric success and the same dysfunctional development of chronic heavy abusers would correlate with similar findings in pediatric patients using it for distinctly different reasons and dosing and administrations. If there is some adverse effect on the pediatric brain, it is unclear if the risks outweigh the benefits in a developing brain of the pediatric population. It may be used anecdotally in some practices with some benefits. Large clinical trials are needed to support this.

About

Introduction/Disclaimer

https://neurologybuzz.com/
Reference

1.  Cooper, et al, “Cannabinoid in attention-deficit/hyperactivity disorder: a randomized controlled trial,” Eur. Neuropsychopharmacol., 2017, Aug., 27 (8):795-808
2.  Kelly, et al, “Distinct effects of childhood ADHD and cannabis use on brain functional architecture in young adults, Neuroimage Clin., 2017, 13:188-200.
3.   Goldschimd, et al, “Effects of prenatal marijuana exposure on child behavior problems at age 10,” Neurotoxicol. Teratol., 2000, May-Jun., 22(3):325-326.
4.  Scott, et al, “Medical marijuana: a review of the science and implications for developmental-behavioral pediatric practice,” J. Dev. Behav. Ped., 2016, Feb., 36 (2):115-123.
5.  Jager, et al, “Cannabis use and memory brain function in adolescent boys: a cross-sectional multicenter fMRI study,” J. Am. Acad. Child Adolesc. Psychiatry, 2010, Jun., 49(6):561-572.

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medical marijuana

A review of mechanisms in medical marijuana: the endocannabinoid pathway, receptors, tetrahydrocannabinol, and cannabidiol 

Virginia Thornley, M.D., Neurologist, Epileptologist

@VThornleyMD

April 28, 2018

Introduction

The Cannabis sativa plant has been known since the beginning of time. It can be traced back 5000 years ago when it was first known to man to alleviate common complaints. It came into the American pharmacopeia in the 19th century then abolished in the 1930’s, likely not coincidentally as the era of prohibition was lifted. It is known to treat ailments such as chronic pain and migraine. In the middle ages, it was used to treat headaches, vomiting, diarrhea, bacterial infections and pain from rheumatological conditions. It was previously known for its psychoactive properties.  It is recently making a resurgence in popularity regarding its medical value. The issue is a topic of hot debate as state laws are at odds with federal laws. Currently, as of April 2018, it is still recognized as a category 1 drug, meaning it is not officially proclaimed to have any medical value despite the long rich history of treating medical symptoms. It is lumped in with other drugs of abuse such as heroin and cocaine.

Background on the Cannabis sativa plant and their metabolites

The Cannabis sativa plant is abundantly rich in phytocannabinoids, the most commonly known and used for its therapeutic value are cannabidiol and tetrahydrocannabinol. The endocannabinoid pathway is comprised of receptors that are coupled with G proteins and cannabinoids (1). In the Cannabis sativa plant, there are 80 phytocannabinoids that can bind to a cannabinoid receptor.

There are 8 major cannabinoids including cannabigerolic acid, delta-9-tetrahydrocannabolinic acid A, cannabidiolic acid A, delta-9-tetrahydrocannabinol, cannabigerol, cannabidiol, cannabichromene, and tetrahydrocannabivarin in the different strains of Cannabis sativa (1).

Ehlsoly, et al, classified it into 11 categories: cannabigerol, cannabichromene, cannabidiol, ∆9-trans-tetrahydrocannabinol, ∆8-trans-tetrahydrocannabinol, cannabicyclol, cannabielsoin, cannabinol, cannabinodiol, cannabitriol, and miscellaneous. ∆9 -trans-tetrahydrocannabinol , cannabinol, and cannabidiol are the most well-studied and well-known.

Cannabidiol is extracted from the hemp portion of the plant considered a male part of the plant, there are no psychoactive properties in cannabidiol. Psychoactivity is defined as anything above 0.3% of THC. Tetrahydrocannabinol is derived from the female portion of the plant, particularly the flowers. Conditions are such that in nurseries only a certain amount of sunlight is given to the plants so that specific strains can be grown. Some plants will be richer in cannabidiol, others will be more THC pure and other swill have an equal amount of CBD and THC but it depends on how the plants are grown and under what conditions.

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Endocannabinoid pathway

It is through the endocannabinoid pathway that one gets the sense of well being after exercise or eating chocolate. It is not through endorphins, serotonin or noradrenergic neurotransmitters as they are too large to cross the blood-brain barrier. Tetrahydrocannabinol acts as a mimetic of Anandamide while cannabidiol acts as a mimetic of 2-Arachidinoylglyerol (or 2-AG). The endocannabinoid system works through cannabinoids, the receptors, transporters, and enzymes.

Receptors

The phytocannabinoids work on cannabinoid receptors. The endocannabinoid system is mediated by 3 parts: the cannabinoids, the cannabinoid receptors, and the enzymes. The receptors are of 2 types, CB1 which is found primarily in the nervous system especially in the areas that subserve pain modulation, memory and movement. The CB2 receptor is more peripherally found specifically in the immune system. The CB2 receptor is found to a lesser extent in other organs including tissues of reproduction, pituitary, heart, lungs, adrenal and gastrointestinal systems.  Cannabinoids also react with the TRPV receptor or the transient receptor cation channel subfamily V. They can also act on G receptors including GPR55 thought to be significant in controlling seizures. Other receptors include GPR12, GPR18, and GPR119 (2).

Tetrahydrocannabinol and cannabidiol and their effect on receptors

THC and CBD are the most well-known and well-studied. THC has psychoactive properties and works as a partial agonist on the CB1 receptor and the CB2 receptor. Cannabidiol which has no psychoactive properties works as an antagonist on CB1/CB2 receptor and an agonist on the CB1 and CB2 receptor. Rather than decreasing the effects of THC, it works in a synergistic manner in combination with THC. It potentiates the THC effects by increasing the CB1 densities. CBD increases vanilloid pain receptors, reduces metabolism and reduces re-uptake of anandamide, THC’s mimetic component. Other studies suggest CBD acts as an indirect agonist by interacting with the CB1 receptor so there are less psychoactive symptoms from THC when the two are combined.

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Pharmacokinetics of tetrahydrocannabinol

Regardless of the way of taking it, the protein binding and the and volume of distribution are not affected by the route of taking it. Pharmacokinetics of creams and vaporizers are unclear. Smoking THC appears to exert an effect within minutes of intake and bioavailability is variable depending upon the extent of inhalation ranging between 2-69%. The effect is within minutes. Half-life increases with each inhalation at 2 puffs inhaled for THC it is 1.9 hours and 5.3 hours in CBD at 8 inhalations it is 5.2 hours in THC and 9.4 hours in CBD at a dosage of 5.4mgTHC/5.0mg CBD and 21.5mg THC/20 mg CBD respectively.

Oral routes may seem to be safer but have more adverse effects including GI symptoms such as nausea, vomiting, and diarrhea. Oral mucosal absorption is rapid within 15 minutes to 60 minutes. Oral tablets are lower in the rate of absorption at about 0.6 to 2.5 hours. The rate of elimination, when taken orally, is biphasic, initially occurring at 4 hours then 24-38 hours after ingestion.

In summary

There is much research ongoing on the mechanisms underlying the medical value of medical marijuana. It is now thought that cannabigerolic acid may have medicinal properties as well. So far, the most well-known and well studied are delta-9-tetrahydrocannabinol and cannabidiol. Most likely as research continues, greater value will likely be attributed towards the phytocannabinoids.

https://neurologybuzz.com/

Introduction/Disclaimer

About

References

  1. Wang, et al, “Quantitative Determination of delta 9-tetrahydrocannabinol, CBG, CBD, their acid precursors and five other neutral cannabinoids by UHPLC-UV-MS,” Planta. Med, 2019, mar., 84 (4):260-266.
  2.  Landa, et al, “Medical cannabis in the treatment of cancer pain and spastic conditions and options of drug delivery in clinical practice,”Biomed. Pap. Med. Fac. Univ. Palacky Olomouc Czech Repub., 2018, Mar; 162(1):18-25.
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Epilepsy

Vagal nerve stimulation device: its role in medically refractory partial epilepsy and reports of weight loss

 

Virginia Thornley, Neurologist, Epileptologist

@VThornleyMD

April 15, 2018

Introduction

The vagal nerve stimulation device is an implanted device that exerts its effort by pulses of electrical activity that stimulates the vagal nerve or cranial nerve X. It had initially been found to work in animal studies in the 1990’s then later applied in clinical studies.

Mechanism of action 

For years, the mechanism was unknown and was used rather effectively in the clinical realm. The elucidated mechanisms were thought to be that the vagal nerve stimulator modifies the highly synchronized electrical activity that occurs in epilepsy through desynchronization via the vagal nerve. In addition, there is increased regional cerebral perfusion, and there is increased GABA neurotransmitters which are inhibitory towards electrical activity causing seizures and a decrease in glutamate which is known to increase excitation with the brain. There are GABA-A receptor increases, an increase in locus ceruleus produced noradrenergic substances which are released through the vagal nerve and an increase in serotonin transmissions through the raphe nucleus.

Role in controlling seizures

In the original open-label trial in 5 clinical trials, the vagal nerve stimulation device was found to be effective in reducing seizures by 50%. 454 patients had the implanted device and clinical information was obtained from 440. A cardiac stimulation device was implanted along with a coil in the ipsilateral vagal nerve. At 1 year of implantation, more than 50% of reduction of seizures occurred in 36.8% of patients at year 1, 43.2% year 2, and 42.7% at year 3.  The most common side effect at year 2 was hoarseness of about 9.8% and headache in 4.5% and at 3 years there was shortness of breath in 3% (4).

In one retrospective study from 1997 to 2008, 436 patients were found with implanted vagal nerve stimulation devices from ages 1-76, 220 were women and 216 were men. 33 had poor follow-up and 3 had removal due to infection. The mean frequency of seizures was better at 50% reduction.  There was 90% better control on 90 patients, >75% control in 162 patients and 50% control in 255 patients, <50% control in 145 patients. Permanent damage to the vagal nerve happened in 2.8% or 11 patients out of the 400 patients (after the removal of the ones lost to follow-up and infected) (5).

Long-term value of vagal nerve stimulating device, effectiveness after 5 years

There have been many studies reported that it may be effective short-term. But there was one pediatric study that reported success in seizure control in longer than 5 years. In a study of 56 pediatric patients ages 4-17, >9.8% were seizure free after 9 months, 24% after 2 years, 46.4% after 3 years and 54% after 5 years.11 out of the 56 patients became seizure free. After 5 years 62% of the patients had fewer seizures after 5 years.

What happens from diagnosis to implantation to use

A patient is identified as medically refractory, meaning a patient who has already failed 2 or more agents. Once control is failed after 2 anti-epileptic drugs after an adequate dosage and trial,  the likelihood of being seizure free becomes significantly less.  It is usually applied to patients with partial seizures, the most common being temporal lobe epilepsy. After appropriate identification is done, the patient undergoes a procedure where a cardiac device is implanted under the skin which generates an electrical impulse. A wire or coil is attached to the vagal nerve which reacts to this signal and emits an electrical pulse which inhibits the seizure which is electrical activity in the brain by disrupting this through various mechanisms. The device can be programmed to have a set frequency, amount of power and can be set to automatic with features where the patient can apply a magnet to inhibit the seizure when it is about to occur. The magnet is typically swiped over the cardiac device which was implanted over the left side of the chest. The settings can be changed in the doctor’s office adjusting according to the number and frequency of seizures.

Common side effects

Some of the most common side effects reported include hoarseness, cough, throat irritation, dyspnea, insomnia, dyspepsia, and vomiting. The symptoms are related to the location of the device near the nerve causing local irritation and likely due to the functions subserved by the vagal nerve.

Incidental weight loss effect

Vagal nerve stimulation device was applied to treatment-resistant patients with depression where an incidental effect on weight loss was found. One study in 33 patients showed that the vagal nerve stimulator implanted in patients seemed to alter cravings for sweet food which may play a part in weight loss (2). There have been some conflicting studies proving that there is no weight loss in vagal nerve stimulating device at the settings recommended in epilepsy in 21 patients (3). In a large study of 503 patients from 15 study centers, vagal nerve blockade was applied intrabdominally. 294 patients were randomized to treated (192) and to control groups (102). Therapy involved electrical stimulation through an external power source to the vagal nerves in the subdiaphragm which inhibits afferent and efferent vagal transmission. At 12 months, the excess weight loss in the treated group was 17% and in the control group, it was 16%. There was no statistic difference between the two groups, however, the post-study analysis demonstrated a possible result in weight loss related to the system check of the devices using low charges which may have caused weight loss in the control group (6).

In conclusion

There is strong evidence that the vagal nerve stimulation device is effective at reducing seizures of >50% of the medication-resistant epilepsy patient. It is effective even after 5 years of implantation. There are very little side effects which are mild to moderate. In addition, it can cause weight loss.

References:

  1. Serdaroglu, et al, “Long-term effect of vagus nerve stimulation in pediatric intractable epilepsy: an extended follow-up,” Child’s Nervous System, 2016, 32 (4):641-646.
  2. Bodenlos, “Vagus nerve stimulation acutely alters food craving in adults with depression,” Appetite, 2007, 48: 145-153.
  3. Koren, et al, “Vagus nerve stimulation does not lead to significant changes in body weight in patients with epilepsy,” Epilepsy Behav. 2006;8:246–249.
  4. Morris, et al, “Long-term treatment with vagus nerve stimulation with refractory epilepsy,” Neurology, 1999, 53 (8):1731-1735.
  5. Elliot, et al, “Vagus nerve stimulation in 436 consecutive patients with treatment-resistant epilepsy: long-term outcomes and predictors of response,” Epilepsy Behavior, 2011, Jan., 20(1):57-83.
  6. Sarr, et al, “The EMPOWER study:randomized, prospective, double-blind, multicenter trial of vagal blockade to induce weight loss in morbid obesity,” Obes. Surg., 2012, Nov., 22 (11):1771-82.

 

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Anxiety, cannabidiol

Anxiety: the science behind anxiety and effectiveness of cannabidiol and tetrahydrocannabinol in anxious patients

Virginia Thornley, M.D., Neurologist, Epileptologist

March 27, 2018

Introduction

Anxiety is a state of unease, the sense of restlessness you feel when you are out of sorts. It may be due to the simple circumstances of being late for a charity dinner to feeling scared out of your wits when your car is trembling on the highway because your wheels are not balanced. Everybody has experienced it at some point in their life. Some more chronically and severely than others. In primitive times, one must redirect their attention from the task of scavenging for food in the jungle to suddenly be alert to imminent danger from the bear prowling behind you. In modern times, one must react quickly to that bus coming at you as you try to cross the street on 51st Street and 5th Avenue. You suddenly look up startled redirecting your focus to the imminently life-threatening event. For someone with clinical anxiety, this would be akin to being fearful every time you try to walk and cross the street despite no threats just the usual fast-paced taxicabs waiting for that green light. There is a chronic response of fearfulness that is not befitting to the situation. Threats are perceived more frequently harboring frequent fearful responses.

Current approach to anxiety

The current armamentarium of a physician includes prescribing anti-anxiety agents, referring to a therapist, recommending relaxation techniques such as yoga, Tai Chi or meditation, or any physician’s all-time fallback choice which is to refer to a psychiatrist. Many medications take weeks to take effect and after all that, not all of them are effective requiring several trials of medications to get to one that may even partially work. A therapist is beneficial, however, cons include the patient not having enough time or resources. In some patients it may help in others, similar to medications, it does diddly squat. In addition, some patients must cope with anxiety through natural means due to the prohibitive nature of their occupation. Some highly sensitive occupations disallow any use of anti-anxiety agents which might be potentially sedating in a patient’s history which could cost them their jobs.  Medications may be helpful in certain populations but it often takes time to find the right agent and the right dose.

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The science and mechanisms behind anxiety

The mechanism of anxiety and its complexities are studied. At the chemical level, it is thought to be due to the lack of serotonin. Many anti-anxiety agents work at the level of the serotonin receptor.  But the thought processes underlying anxiety are far more complex than at a single chemical level which likely is the reason why many medications do not work given the complexity of the emotional response.

Neuroimaging studies have elucidated that anxiety may be attributed to the involvement of an amygdala to prefrontal cortex circuit. Instead of the normal fear response one has to certain stimuli, the amygdala is overly responsive to the threat. This leads to an abnormal attentional and interpretive response level that is consistently fearful.  For instance, your bakery might be the best in town but if the client is highly anxious, any little mistake on that wedding cake may be perceived as a personal slight giving rise to an extremely anxious response causing them to want their money back. In other words, the level of anxiety is greatly out of proportion to the situation. There is nothing that bakery could have done to ease that person’s anxiety over the cake.

Patients with anxiety are selectively attentive to threat-related situations. Anxious patients perceive neutral events with negative connotations and potentially threat-related. Stimuli with conditioned threat significance may elicit attention and lead to physiologic responses including increased heart rate, sweating, heavier breathing. This may be the reason why in dealing with an anxious person, no matter what has been said that individual has a hyperalert response and has a very low threshold for a fearful response to a threat-perceived situation when the situation is very neutral (1). For example, you could be the most highly skilled neurosurgeon in the world, if your delivery of the prognosis is a 60% chance of recovery, that could be a source of great angst. The clinically anxious person will hear how she or he  will have the 40% chance of not recovering.

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Cannabidiol 

Cannabidiol is the non-intoxicating phytocannabinoid from the Cannabis sativa plant. It has a weak affinity for the CB1 receptor and one needs 100 times the amount to get the same euphoria as tetrahydrocannabinol. Cannabidiol is found to help with anxiety. It works at the level of the 5HT-1 receptor to exert its anxiolytic properties. A combination of cannabidiol and tetrahydrocannabinol often called Indica is often used for anxiety and insomnia. It is often used by patients with anxiety primarily at night due to its calming and sedating properties.

In one study of 24 patients with anxiety who were about to give a presentation, cannabidiol was given at 600mg. The anxiety, cognitive impairment, and alert arousal response were much lower compared to the control group who had a placebo. The placebo group had much higher anxiety, greater discomfort, and alert responses (2).

Although federally illegal in many states despite medical marijuana laws and dispensaries popping up around the nation, medical marijuana is an alternative agent that should be considered in patients who are medically refractory to medications, psychotherapy, and other techniques. It has a valuable place in the physician’s medicine bag in treating anxiety and illnesses related to anxiety-related disorders.

References

  1. Bishop, et al, “Neurocognitive mechanisms of anxiety: an integrative account,” Trends in Cognitive Behavior, article in press.
  2. Bergamaschi, et al, “Cannabidiol reduces the anxiety induced by simulated public speaking in treatment-naive social phobia patients,” Neuropsychopharmacology, 2011, May, 36 (6): 1219-26.
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chronic pain

Medical Marijuana: a non-intoxicating pain-relieving solution to the opioid epidemic?

Virginia Thornley, M.D., Neurologist, Epileptologist

March 24, 2018

Introduction

Any news outlet you peruse is bound to have mention of the current opioid crisis looming on the horizon. Opioids are commonly prescribed as the last resort for patients with chronic pain who have failed conventional medications, interventional measures such as epidural injections or surgery, non-pharmacologic measures such as physical therapy and even Eastern techniques such as acupuncture. With tolerance a common problem and patients needing higher and higher dosages for pain control because of the properties of opioids, it is little wonder that chronic pain control is difficult to maintain.

The hot topic of debate in many states is the recognition of medical marijuana as a legitimate medication for chronic ailments. However, because of the stigma it has incurred being well-known for its psychoactive properties and widely seen in pop culture in movies with kingpins smoking it for recreation, the medicinal values are often overshadowed and lack of side effects in low doses is easily overlooked.

Not your stereotypical patient and not your direct referral

Patients and even physicians likely have a preconceived notion of who seeks medical marijuana. While chronic pain is top of the list, often times, it is discovered by the hard-working carpenter who discovered it online and found a small scientific article on non-pharmacologic treatments trying to come off sedating pain-relieving medications. It will be the former business owner who lived an enjoyable life being active dancing or the woman afflicted with an autoimmune disorder and has failed every medication under the sun. Many times patients come in not because they want to feel good but because it is their last resort and they’ve exhausted every treatment option known to mankind. They dislike the side effects of the strong painkillers such as opioids and just want the pain to stop and live a normal life. It is amazing how indirectly patients hear about the wonders of medical marijuana, it will usually be a neighbor who swears by it, or somebody’s friend who mentions it out of the blue.  Oftentimes, it is by word of mouth since the few physicians interested in recommending it are very reluctant to advertise with good reason.

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Mechanisms of cannabidiol and tetrahydrocannabinol

Medical marijuana has been used since B.C. period for thousands of years as a medication. It was incorporated into the pharmacopeia of American medicine in the 1850’s until it was banned in the 1930’s. It regained popularity and notoriety as a recreational substance. However, more and more patients are turning towards this now alternative medication after years of frustration towards the ineffectiveness and adverse effects of conventional medications.  The endocannabinoid pathway is found inherently in the system and is responsible for the runner’s high that people get after a vigorous run or after exercising and gives the sense of well-being. The CB1 receptor is found most abundantly in the central nervous system which is likely why many neurological conditions are found to benefit from its use. The CB2 receptor is most commonly found in the immune system. As more research is pursued, there are CB receptors found diffusely throughout many organ systems.  Cannabidiol weakly interacts with the CB1 receptor. It takes at least 100 times cannabidiol to attain the same intoxication one gets with tetrahydrocannabinol, the substance which is more popular and found in the marijuana joints people smoke to obtain euphoria. THC at low concentrations is effective in treating many different medical conditions. It must be used in conjunction with CBD so that side effects are offset. Cannabidiol has no intoxication while low doses of THC does not give euphoria one associates with this drug. There is no tolerance.

Scientific evidence cannabidiol and tetrahydrocannabinol work in chronic pain and other medical diseases

In animal studies, it is well known to reduce seizures by inhibiting the excitation within the hippocampus of the brain where seizures are commonly propagated (http://www.pnas.org/content/early/2017/09/26/1711351114).There are many clinical trials in humans attesting its efficacy at controlling seizures effectively.  CB1 receptors appear to be increased in many neurological disorders which implies it is a compensatory mechanism for diseases. In Parkinson’s disease, there are increased CB1 receptors which may help with the reduced dopamine commonly found in Parkinson’s disease. 9tetrahydrocannabinol was found to lower intraocular pressure in glaucoma in rabbits (https://www.ncbi.nlm.nih.gov/pubmed/6329602). Sativex is a combination of THC:CBD which reduces spasms in patients with multiple sclerosis and has been available in Europe for several years now with very little side effects http://jnnp.bmj.com/content/87/9/944. There is extensive evidence in both animal and human models that it works in chronic pain (https://www.ncbi.nlm.nih.gov/pubmed/26830780). Many diseases are being evaluated for mechanisms on which CBD and THC may exert its effects. It has been found to have anti-oxidant and anti-inflammatory properties which are important mechanisms by which many diseases cause pathology. In cancer cell cultures, it has been found to reduce proliferation of tumor cells in urologic cancer and reduce the pro-inflammatory states that are necessary for metastatic conditions (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5434502/).CBD interacts with the 5HT1 receptor where many anti-depressants and anxiolytic medications exert their effects, making CBD an effective anxiolytic. It works to stimulate appetite and is commonly used by patients with cancer for anorexia and end-stage cancer pain.

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In conclusion

In summary, cannabidiol and tetrahydrocannabinol are effective medications in treating pain from many chronic illnesses and is not reserved for patients with terminal illness. Despite the reticence of physicians, Congress and even patients, there is overwhelming evidence that cannabidiol and tetrahydrocannabinol are effective in many different diseases, although in some conditions there’s a long way to go from preclinical data to human trials.  It is fairly clear in many disease states, medical marijuana is significantly effective. There is no tolerance and may be an effective treatment for patients with chronic pain. CBD by itself has no euphoric properties and low concentrations of THC do not give intoxicating psychoactive effects. These are 2 alternatives that may provide relief and solution to the growing epidemic of the opioid crisis.

Introduction/Disclaimer

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Amyotrophic lateral sclerosis

Non-pharmacologic aspects of ALS: correlation of higher BMI with greater survival, beneficial use of cannabidiol, respiratory evaluation, exercise and anesthetic considerations 

Virginia Thornley, M.D., Neurologist, Epileptologist

March 4, 2018

ALS is a progressive neurodegenerative illness which affects the lower motor neurons causing progressive weakness and eventually respiratory failure. There are currently only 2 prescription agents available for slowing the progression of the disease. Management is largely symptomatic treatment of debilitating symptoms.  Much consideration is being directed towards alternative treatments such as dietary considerations and use of cannabidiol.

ALS and supplements and BMI

Based on one large review of studies, there was not enough evidence to support recommendations of Vitamin A, and C or Coenzyme Q10. For Vitamin B complex, Homocysteine, Vitamin D, there is limited data which is not enough to support or refute recommendation, more clinical trials are needed. Vitamin E may be beneficial in preclinical patients with a familial tendency. Omega-3 was found to accelerate disease progression with increased vacuolization of anterior horn cells and are deleterious in presymptomatic patients. L-Carnitine may increase survival time with a slower ALSFRS or ALS functional revised score and greater FVC volumes but more trials are needed (1). Body mass index of less than 18.5kg/m is found with less survival time, while those with a higher BMI have greater survival time. One small study suggested a high calorie, hypercaloric enteral diet was tolerable in patients but unclear if associated with better outcome in terms of survival time.

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Cannabidiol as a novel therapeutic agent

Cannabidiol is known in animal models to be anti-inflammatory and anti-oxidant. In the G93A SOD-1 mouse model, it was found to slow progression of the disease and increase survival time. In a study of 13 patients, it reduced drooling, loss of appetite, pain, and spasticity.

In one study, cannabidiol was used in human gingiva-derived mesenchymal stromal cells. The transcriptomic sequence in the next generation shows a change in gene expression in ALS related genes. There was a change in the genes connected to ALS regarding oxidative stress, mitochondrial dysfunction and excitotoxicity in the human gingiva-derived mesenchymal stromal cells when treated with cannabidiol. This suggests that cannabidiol may serve as a modulatory role in the early pathogenesis of ALS (2).

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Other aspects of ALS

Exercise 

Studies regarding exercise showed flaws in methodology or were in small numbers. Therefore, based on available studies it is unclear if exercise benefits a patient’s long-term outcome.

 

Sialorrhea

Sialorrhea should be addressed. Aside from conventional medications, other options include botulinum toxin and small doses of radiation therapy delivered to the salivary glands.

Anesthesia 

Anesthetic agents such as neuromuscular blockers are contraindicated in patients with ALS due to the risk of increased potassium release. In one study of 51 patients with ALS, general anesthesia was safely administered.

Pulmonary function 

Pulmonary function tests are monitored every few months depending on the rapidity of the progression of the disease. Non-invasive positive pressure ventilation is used in patients with ALS with an oral or nasal mask. As force vital capacity (FVC) declines, it may be administered through a bi-level positive airway ventilation machine continuously at night(1).

Introduction/Disclaimer

About

https://neurologybuzz.com/

References

1. Karam, et al, “Palliative care issues in amyotrophic lateral sclerosis: an evidence-based review,” American Journal of Palliative Care, 2016, Feb., 33(1):84-92.

2. Rajan. et al, “Gingival stromal cells as an in vitro model: cannabidiol modulates genes linked with amyotrophic lateral sclerosis,” Journal of Cellular Biochemistry, 2017, Apr., 118(4):819-828.

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