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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Anxiety

Do anti-depressants or anxiolytics cause lower levels of vitamins and minerals?

Virginia Thornley, M.D., Neurologist, Epileptologist
November 4, 2019
A recent question prompted this literature search. We know that patients ho are depressed often complain of fatigue. But which came first the chicken or the egg?
Fatigue could be a result from not sleeping well due persistent thoughts and rumination at night. But can long-term anti-depressants and anxiolytics cause a lowering of vitamins and minerals leading to fatigue? We search the literature.
In one meta-analysis, folate levels were found to be lower in a small number of patients compared to those who were not depressed. However, it does not mention if the use of anti-depressants or anxiolytics were the cause of these lower values. This was an observation (1).
In another study, 355 patients were studied later in life, 60’s and higher in age. Lower levels were found to be lowered which could be a potential cause of later life depression. It is not clear if these patients were on anti-depressants leading to lower Vitamin D levels (2).
In one review, 4 studies were found that an improvement in the the thiamine status led to improved mood. The same study found that folate deficiency led to depression and iron deficiency anemia can lead to fatigue and depression (3).
The take home message is that it is not clear whether anti-depressants and anxiolytic agents used long-term can result in lower levels of minerals and vitamins.
However, it has been studied that lower levels of certain minerals and vitamins can lead to or be associated with depression.
Neurologybuzz.com
Reference
  1. Bender, A., Hagan, K.E., Kingston, N., The association of folate and depression: a meta-analysis. J. Psychiatric Res. 2017 Dec. 95:9-18
  2. Oude Voshaar, R.C.,Derks, W.J., Comiis, H.C., Schoevers, R.A., de Borst, M.H., Marijnissen, R.M. Antidepressants differentially related to 1,25-(OH)2 vitamin D3 and 25-(oH) vitamin D3 in laterlife depression. Transl Psychiatry. 2014, Apr. 15;4:e383
  3. Benton, D., Donohue, R.T. The effects of nutrients on mood. Public Health Nutr. 1999 Sep; 2(3A):403-409
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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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migraine

Effects of barometric pressure changes in weather change in patients with migraine

Virginia Thornley, M.D.
October 9, 2019
A common question that is asked in the office setting is whether weather changes can increase migraines.
In one study of 98 patients followed 45 days, higher humidity between the warm months of April and September correlated with increase number of migraines (1).
In a 7-year study of ER patients, an increase of barometric pressure resulted in more ER visits by patients with migraine. There were less visits when it was a decrease in pressure. There was no correlation with migraine with the actual magnitude of barometric pressure change. Tropical air masses correlated with more ER visits compared to polar masses (2).
In a smaller study of 28 patients followed over 1 year, weather changes correlated with increased migraine frequency in 64%. 14 of those reported low barometric pressure to be associated with it (3).
In summary, despite some mixed results regarding reduction of barometric pressure, if a weather change affects a patient’s underlying condition, it is likely a trigger.
This is information only not advice please see your doctor.
Neurologybuzz.com
Reference
  1. Li, W., Bertisch, S.M., Motofsky, E., Buettner, C., Mittleman, M.A., Weather, ambient air pollution, and risk of migraine headache onset among patients with migraine. Environ. Int. 2019, 132:105100
  2. Elcik, C., Fuhrmann, C.M., Mercer, A.E., Davis, R.E., Relationship between air mass type and emergency department visits for migraine headaches across Triangle region of North Carolina. Int. J. Biometeor. 2017, Dec. 61(12):2245-2254
  3. Kimoto, K., Alba, S., Takashima, R., Suzuki, K., Takekawa, H., Watanabe, Y., Tatsumoto, M., Hirata, K., Influence of barometric pressure in patients with migraine headache. Intern Med. 2011. 50(18):1923-8
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neurology

Can anti-psychotic agents reduce brain volume?

Virginia Thornley, M.D.
Neurologist, Epileptologist
October 9, 2019
Can medications cause cerebral atrophy? Atrophy refers to shrinkage of the cells causing the appearance of the brain to have less volume than usual.
This question was asked last week. Anti-epileptics such as phenytoin is well-known in the literature and clinically to cause cerebellar atrophy. But what about other agents such as anti-psychotics.
Animal studies
In one animal study, exposure to anti-psychotic drugs showed a reduced volume of brain on volumetric studies. The number of cells remained the same but the volume was increased for cells in the anterior cingulate gyrus which is in the  limbic lobe. The limbic lobe subserves emotions and has influence on memory. Animal studies do not always correlate with human responses.
Human studies
One small study showed that the thalamic volume was reduced after olanzepine administration. This was a small study of 10 patients (2).
While there is some information in the literature the studies are animal studies and small human studies. More information is needed. Based on the current literature, there are not enough significant studies to correlate atrophy with use of anti-psychotics.
References
  1. Vernon, A.C., Crum, W.R., Lerch, J.P., Chege, W., Natesan, S., Modo, M., Cooper, J.D., Williams, S.C., Kapur, S. Reduced cortical volume and elevated astrocyte density in rats chronically treated with anti-psychotic drugs-linking magentic resonance imaging findings to cellular pathology. Biol Psychiatry. 2014, Jun. 15, 75(12):982-90
  2. Khorram, B., Lang, D.J., Kopala, L.C., Vandorpe, RF.A., Rui, Q., Goghari, V.M., Smith, G.N., Honer, W.G. Reduced thalamic volume in patients with chronic schizophrenia after switching from typical anti-psychotic medications to olanzepine. Am J sychiatry. 2006, Nov. 163 (11):2005-7
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dementia

Animal study demonstrating CBD’s (cannabidiol) effects on neuroplasticity and memory loss

Virginia Thornley, M.D.
Neurologist, Epileptologist
August 26, 2019
In an animal study, one group demonstrates that Cannabidiol may help with the neuroplasticity in patients with Alzheimer’s disease (1).
LTP in the hippocampus is the long-term potentiation seen that elevates the efficacy of synapses involved in memory. Beta-amyloid peptide is toxic towards this  feature. When animals were pretreated with CBD the neurotoxicity was found to be reduced against beta-amyloid peptide. The same study showed that it did not involve the 5-HT1a, CB1 or adenosine receptors (1).
There have been other previous studies showing that cannabidiol could have protective effects against the toxic effects of beta-amyloid peptide which is involved in the neurodegenerative process seen in Alzheimer’s disease.
More clinical randomized control trials are needed. Animal studies do not always translate into human studies.
Neurologybuzz.com
References
  1. Hughes, B., Herron, C.E., Cannabidiol reverses deficits in hippocampal LTP in a model of Alzheimer’s disease. Neurochem. Res. 2019, Mar. 44(3):703-713

This is medical information not medical advice. Please consult with your physician.

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