Essential tremor, Uncategorized

Deep brain stimulation and essential tremor

Virginia Thornley, M.D.
Neurologist, Epileptologist
November 6, 2019
Essential tremor is now treated with implantation of a deep brain stimulating device. It has been approved for treatment for Parkinson’s disease, essential tremor, dystonic tremor and obsessive compulsive disorder (1).
Basically, within the brain, there is a recurrent loop that is not inhibited by the correct feedback inhibition resulting in repetitive actions. In obsessive-compulsive disorders, there are repetitive thoughts and actions since this loop is not controlled.
In one study, the ventral intermediate nucleus (VIM) was stimulated in 98 patients with Parkinson’s disease, essential tremor and dystonic tremor with sustained improvement. There was significant long-term improvement even after 10 years(2).
The mechanism is unclear. However, certain nuclei stimulated were found to result in side effects. Thalamic stimulation resulted in fatigue. Subthalamic nuclear implantation was found to give rise to depression and suicidality(3).
Neurologybuzz.com
References
  1. Naestromm, M., Blomstedt, P., Hariz, M., Bodjund, O., Deep brain stimulation for obsessive-compulsive disorder: knowledge and concerns among psychiatrists, psychotherapists and patients,  Surg. Neurol Int. 2017; 8:298 
  2. Cury, R.G., Fraix, V., Castrioto, A.,Perez-Fernandez, M.A., Krack, P., Chabardes, S., Seigneuret, E., Alho, E.J., Benabid, A.L., Moro, E. Thalamic deep brain stimulation in Parkinson disease, essential tremor and dystonia. Neurology. 2017 Sep 26;89(13):1416-1423
  3. Zarzycki, M.Z., Domitrz, I., Stimulation-induced side effects after deep brain stimulation-a systematic review. Acta Neuropsychiatr. 2019, Aug 27:1-24
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cannabinoids, Uncategorized

What are the risks of vaping medical cannabinoids in the state of Florida?

Virginia Thornley, M.D.
October 9, 2019
Given the recent rash of deaths thought to be caused by vaping e-cigarettes, patients are scrambling to ask their doctors regarding the risks of vaping medical cannabinoids.
Many of the reports reporting deaths have been with e-cigarettes which do have chemicals that can potentially cause irreversible damage to the lungs.  Some reports report that THC oils were used but do not state the source. THC oils were reported to be placed in the vaporizer device used for e-cigarettes to be vaped. In Florida, medical products used in vaping for medical purposes from regulated dispensaries are from all natural products, a very different set-up compared to the components found in e-cigarettes.
It is not clear if some of these reports are from tightly regulated medical marijuana dispensaries. In the state of Florida, there have been no reports of deaths related to vaping cannabinoids used for medical use that come from stringently regulated dispensaries. In the state of Florida, medical cannabinoids have strict regulations and there is a vertical distribution meaning the products are with the company from time they are grown as a seedling to the time of dispensing so that the company is in complete control of the product being dispensed.
At this point, October 2019, there have been no reported deaths due to vaping medical cannabinoids in Florida when taken from legal regulated dispensaries. The lung-related illnesses associated with vaping in Florida are related to vaping from e-cigarettes which may also have other substances added.  This is completely different from vaping the cannabinoid medical products which are all natural products from medical dispensaries.
We turn to research for the analysis of the potential risks involved with vaping. There is one study but it involves vaping cannabinoids using e-cigarette devices. The gas-thermal degraded products have not yet been thoroughly analyzed. In this study, there is potential exposure to benzene, methacrolein and methyl vinyl ketone. Tetrahydrocannabinol alone and mixed with terpenes can lead to elevated levels of isoprene. Terpenes may lead to higher gas products. Overall, gas-phase products are much lower compared to smoking products (1). There has been little research on vaping medical cannabinoids dispensed from the dispensaries and so far, no deaths have been reported from cannabinoids coming from regulated dispensaries in Florida.
This is information only not advice. Please consult with your physician.
Neurologybuzz.com
Reference
  1. Meehan-Atrash, J., Luo. W., McWhirter, K.J., Strongin, R.M. Aerosol gas-phase components from cannabis e-cigarettes and dabbing: mechanistic insight and quantitative risk analysis. ACS Omega. 2019, Sep. 16,;4(14):6111-16120
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multiple sclerosis, Uncategorized

The impact of immunomodulating agents used in multiple sclerosis on the risk of cancer

Virginia Thornley, M.D., Neurologist, Epileptologist
June 14, 2019
Introduction
Multiple sclerosis is already an illness where the immune system recognizes the nervous system specifically the white matter tracts as foreign and attacks it. The complex cascade of mechanisms make adequate treatment challenging. Many treatments focus on the inflammatory mechanism with little attention on the degenerative mechanism involved.
Presentation of symptoms come in a wide variety depending on the the location of the multiple sclerosis plaque in the brain.
Patients may have concomitant morbidities which may make treatment challenging.
 
Immunomodulating agents and its impact on cancer
Many of the newer treatments for multiple sclerosis work at the level of the immune system through immunosuppression, the newer ones tend to be very potent. With greater efficacy comes greater risks including the risk of cancer.
Some of the newer medications can potentially increase the risk of cancer. Higher risk of cancer was found in many reports to occur with use of cyclophosphamide, azathioprine and mitoxanthrone. Fingolimod, natalizumab and alemtuzamab  can potentially increase the risk of cancer, these agents lack long-term data and work through the immune system. Dimethyl fumarate, terifluonimide, ocrelizumab, daclizumab and cladribine merit mandatory risk management plans to detect cancer before its use.
Reference
  1. Lebrun, C., Rocher, F., Cancer risk in patients with multiple sclerosis: potential impact of disease-modifying drugs. CNS Drugs. 2018, Oct. 32(10):939-949 doi:10.1007/s40263-018-0564-y
Disclaimer: This is medical information only not medical advice. Please consult your physician
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