Christina H. Hernon, MD, University of Massachusetts Memorial Hospital, Worcester, MA Brian J. Wolk, MD, Loma Linda University Medical Center, Loma Linda, CA Yo! GABA GABA and Other Key Players in "Natural" Seizures
Christina H. Hernon, MD, University of Massachusetts Memorial Hospital, Worcester, MA
Brian J. Wolk, MD, Loma Linda University Medical Center, Loma Linda, CA
Yo! GABA GABA and Other Key Players in "Natural" Seizures
Objectives:
Appreciate the variety of mechanisms of natural toxin-induced seizures and how they interact
Be able to visually identify at least 5 natural toxins causing seizures
Be able to describe the mechanism of seizures in at least 5 natural toxins
Disclosures:
Dr. Wolk is a Co-investigator for Analatro (Black Widow Fab2 Antivenom)-Instituto Bioclon/Rare Disease Therapeutics
Help, I just had a seizure in my
hand!
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Horrible Herbs
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Yo! GABA GABA
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Look-a-likes
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That wasn’t a seizure; that was
a dance move
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Category 1 questions follow
Quest
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The primary mechanism of the toxin found in this substance.
100Category 1
http://www.flickr.com/photos/bonjourwill/4528624762/sizes/o/
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Adenosine receptor antagonism
100Category 1
Quest
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Rick James may have used a certain substance derived from this plant:
200Category 1
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Coca Plant
200Category 1Coca Picture Refernce: http://upload.wikimedia.org/wikipedia/commons/7/72/Colcoca04.jpg
Quest
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This plant native to Southeast Asia:
Hint: commonly used to ‘stun’ fish
300Category 1
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Plant: Anamirta cocculus or Fishberries
300Category 1Picture Reference: http://upload.wikimedia.org/wikipedia/commons/7/70/Anamirta_cocculus_02.JPG
Quest
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This toxin is derived from a large tree with broad-leaves.
It is native to China and Japan, but is considered an invasive species in the Southern United States.
400Category 1
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Camphor
400Category 1
http://plants.ifas.ufl.edu/misc/reco_cards/cincam.pdf
http://i00.i.aliimg.com/photo/v0/105180782/Camphor_Bulk.jpg
Quest
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Latin name for the genus, toxin and mechanism of toxicity:
500Category 1
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Aconitum, Aconitine, & Sodium-Channel Blockade
Also known as Wolfsbane or Monskhood
500Category 1
Picture Reference: http://upload.wikimedia.org/wikipedia/commons/7/70/Aconitum_napellus_Ticino.jpg
Category 2 questions follow
Quest
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Plant and mechanism of action of its toxin:
100Category 2
http://farm9.staticflickr.com/8301/7808736868_5ce5abf011_b.jpg Creative Commons License
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Tobacco/Nicotinic
100Category 2
Quest
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This bane of livestock is terribly toxic.
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Cowbane or Cicuta Virosa
200Category 2
Quest
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This edible ‘pea’ contains the neurotoxin ẞ-N-oxalylamino-L-alanine (BOAA) which is a glutamate agonist
300Category 2
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Lathyrus Sativa (Chickling Pea)
300Category 2
Quest
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This fall flower may give you seizures, but that could be the least of your problems:
400Category 2
http://s0.geograph.org.uk/photos/54/59/545962_fd7cb876.jpg“© Copyright Evelyn Simak and licensed for reuse under this Creative Commons Licence.”
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Colchicum autumnale/autumn crocus (Colchicine)
400Category 2
Quest
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This relative of water hemlock from the island of Sardinia may give you a Sardonic Grin:
500Category 2
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Oenanthe fistulosa (Water Dropwort)
500Category 2
http://commons.wikimedia.org/wiki/File:Illustration_Oenanthe_aquatica0.jpg
Category 3 questions follow
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How does cocaine cause seizures?
100Category 3
http://farm3.staticflickr.com/2190/2170100460_2094dd2d6d_o.jpg
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Adrenergic/Sympathomimetic stimulation
100Category 3
Quest
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The antidote for ingestion of this savory shroom:
200Category 3
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Pyridoxine
-Gyromitrin metabolized to Monomethylhydrazine
200Category 3
Picture Reference: http://upload.wikimedia.org/wikipedia/commons/9/97/Fr%C3%BChjahrslorchel.JPG
Quest
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300Category 3
Before Redbull and Vodka, you could get your uppers &
downers from a drink made with this plant:
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Artemisia absinthium or Wormwood
300Category 3Picture Reference: http://upload.wikimedia.org/wikipedia/commons/f/f5/Artemisia_absinthium_0002.JPG
Quest
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400Category 3
Mechanism of this toxin found in mussels; linked to severe permanent neurologic damage and the deaths of > 400 Sea Lions:
http://cleanfish.com/system/images/BAhbB1sHOgZmIjsyMDExLzAzLzIxLzE2LzUwLzMyLzMxMS9TYWx0U3ByaW5nX011c3NlbHNfV2hvbGVfOC5qcGdbCDoGcDoKdGh1bWIiDTQ1MHg0NTA+/SaltSpring_Mussels_Whole_8.jpg
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Glutamate Analogue/NMDA Agonist
400Category 3Picture Reference: Figure 1 in Teitelbaum JS, Zatorre RJ, Carpenter S, Gendron D, Evans AC, Gjedde A, et al. Neurologic sequelae of domoic acid intoxication due to the ingestion of contaminated mussels. The New England journal of medicine. 1990;322(25):1781-7.
Quest
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The toxin and mechanism, respectively, of Anamirta cocculus
500Category 3
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Toxin: Picrotoxin
Mechanism:GABA inhibitor (non-competitive)
May also inhibit glycine receptors
500Category 3
Category 4 questions follow
Quest
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Socrates did NOT eat this:
100Category 4
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Cicuta Maculata (Water Hemlock)
100Category 4Picture Reference: http://www.illinoiswildflowers.info/wetland/photos/wt_hemlock1.jpg
Quest
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This “false” fungus may be “tasty” but ingestion is inadvisable
200Category 4
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Gyromitra Esculenta or the False Morel
200Category 4
Quest
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The flowers of this plant may resemble the pants of a person from a Northern European country; this plant may also cause seizures in livestock:
300Category 4
http://farm5.staticflickr.com/4015/4525160667_8fb31c049c_b.jpg Creative Commons License
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Dicentra cucullaria/Dutchman's breeches
Toxin: Bicuculline
300Category 4
Quest
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This bad actor causes seizures less frequently than its cousin, and may be identifiable by its coloration:
400Category 4
http://farm1.staticflickr.com/208/508080682_a19188ceb5_o.jpg Creative Commons License
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Conium maculatum or Poison Hemlock
400Category 4
Quest
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This stellate assassin is sometimes mistaken for its benign Chinese cousin:
500Category 4
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Illicium anisatum/Japanese star anise (Anisatin)
-non-competitive GABA (channel) inhibition
500Category 4Picture Reference: http://2.bp.blogspot.com/_a5abCT2isic/TBl3SSBhWQI/AAAAAAAACwM/P63cuGW_gzc/s400/star_anise.jpg
http://upload.wikimedia.org/wikipedia/commons/6/62/Illicium_verum_2006-10-17.jpg
For comparison: Illicium verum or
Chinese Star Anise (Non-toxic)
Category 5 questions follow
Quest
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The NMDA agonist in this fungus theoretically could causes seizures, but rarely does due to it’s concomitant CNS depressant
100Category 5
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Amanita Muscaria or Fly agaric
100Category 5
Quest
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200Category 5
The name of the NMDA agonist in this mushroom:
http://s0.geograph.org.uk/geophotos/02/12/31/2123114_83948608.jpg
“© Copyright JamesB and licensed for reuse under this Creative Commons Licence.”
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Ibotenic Acid
200Category 5
Quest
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Chew on this, and you might get a little rush:
300Category 5
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Qat or Khat (Cathinones)
300Category 5
Quest
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Found in some traditional remedies, this toxin may give you a convulsion to remember
400Category 5
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Strychnos Nux Vomica or
Strynchine
400Category 5
Quest
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Specific mechanism by which this cellular asphyxiant may cause seizures (other than general cellular asphyxia):
500Category 5
http://upload.wikimedia.org/wikipedia/commons/9/9e/Autumn_Red_peaches.jpg
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Glutamic Acid Decarboxylase Inhibition
500Category 5