Febrile seizure
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Febrile seizure
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Febrile seizures p. 531
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Febrile seizures are seizures that happen with a fever, and they typically occur in young children between six months and five years of age.
Now, neurons are the main cells of the nervous system. They’re composed of a cell body, which has all the cell’s organelles, and nerve fibers, which are projections that extend out from the neuron cell body.
Nerve fibers are either dendrites that receive signals from other neurons, or axons that send signals signals called action potentials along to other neurons.
Where two neurons come together is called a synapse, and that’s where one end of an axon sends neurotransmitters to the dendrites or directly to the cell body of the next neuron in the series.
Some neurotransmitters bind to the receptors and tell the cell to open up the ion channels and relay an electrical message and these are called excitatory neurotransmitters.
But there are others which can close the ion channels and prevent an electrical message from going through and these are called inhibitory neurotransmitters.
The main excitatory neurotransmitter in the brain is glutamate.
Glutamate binds to NMDA receptors which tell the cell to open up calcium ions channels. Since calcium has a positive charge, it makes the inside of the cell more positive and that helps triggers an action potential.
On the flip side, the main inhibitory neurotransmitter in the brain is GABA.
GABA binds to GABA receptors, which tell the cell to open up chloride ion channels.
Since chloride has a negative charge, it makes the inside of a cell more negative and that inhibits an action potential.
During a seizure, large groups of neurons become active synchronously, meaning all at the same time.
And in a febrile seizure, the trigger for that neuronal activity is a fever.
So that makes you wonder, why? Well, we actually don't know for sure, but there are some possible explanations. The first is that a fever, raises the core body temperature and it makes neurons more excitable than usual - meaning that action potentials are more likely to happen.
Summary
Febrile seizures are a type of seizure that can occur in children with fever (>38 ��). A seizure is a sudden, uncontrolled electrical disturbance in the brain. Febrile seizures typically affect children from 6 months to 5 years old, who do not have epilepsy or any other defined cause of seizures.
Febrile seizures usually occur in about 2% �4% of children younger than 5 years of age. Boys are more likely than girls to have febrile seizures, and there is a risk for recurrence if a child has had one before. Even though most febrile seizures are self-limiting and last for just a few seconds to minutes, some can last for up to 30 minutes, and antiseizure medications are recommended for those that continue for more than 5 minutes.
Sources
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- "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
- "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
- "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
- "Fever, febrile seizures and epilepsy" Trends in Neurosciences (2007)
- "Brain Inflammation in Epilepsy: Experimental and Clinical Evidence" Epilepsia (2005)
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