EPILEPSY: A DISEASE FOR THE LOVESICK

Tavishi

On February 14th in the middle ages, children with epilepsy were given keys.

Valentine's Day didn't start off as a holiday of love; rather, that is what it has become. But in historical Italy, Valentine's Day, among many other things, was used as a way to try to cure children of epilepsy. St. Valentine's Keys were given to those with epilepsy and seizure problems as a whole to ward off the disease.

Although we now better understand how epilepsy works, the practice of giving out St. Valentine's Keys still continues, and people continue to be born with epilepsy.

Epilepsy, at its core, is a recurring seizure disease brought about by excessive electrical activity within the cerebral cortex.

Seizures are generally caused by an over-excitation of neurons and an under-inhibition of neurons. This change in balance of excitation and inhibition is often caused by genetic mechanisms changing proportions of neurotransmitters and reaction to those neurotransmitters.

Two neurotransmitters play a crucial role in seizures: GABA and glutamate. While GABA is the primary inhibitory neurotransmitter, glutamate is its polar opposite, and the primary excitatory neurotransmitter. In individuals with epilepsy, glutamate levels are oft markedly increased, and GABA levels markedly decreased.

gimme gimme gimme a man after midnight - gabba

Seizures come in many forms. They start as either generalized, or focal seizures. Whereas generalized seizures are not localized to one area of the brain, focal seizures occur in only one hemisphere or one lobe of the brain. Seizures in epilepsy generally result in muscle convulsions, and begin as either generalized or focal. 

Most seizures start off focal. Because focal seizures are localized to such specific areas of the brain, they often begin with sensory creations like hallucinations (occipital lobe).

Generalized seizures come in six forms: clonic, tonic, tonic-clonic, myoclonic, absence, and atonic. These seizures are classified based off of the type of muscle convulsions experienced. Limbs shaking in unison constitute a clonic seizure, whereas tonic seizures produce constant muscle contraction. Tonic-clonic seizures, or grand mal seizures, consist of a tonic and clonic phase. A myoclonic seizure has irregular, brief, muscle spasms, sort of like a more irregular clonic seizure. An absence seizure produces a loss of consciousness, and an atonic seizure causes a loss of muscle tonicity.

eeg demonstrated above! seizure where super squiggly

Epilepsy, contrary to popular beliefs, isn't caused by a lack of keys in children. Rather, epilepsy is often produced by genetic predisposition. Epilepsy is often a side effect of genetic diseases like Sturge-Weber syndrome and tuberous sclerosis complex. However, many specific mutations produce epilepsy, like PCDH19 and GRIN2A mutations.

PCDH19 is a gene found on the X chromosome, and produces the protein protocadherin 19. Protocadherin 19 is among the many cadherin proteins that use calcium to join cells together, and also, plays a role in intracellular signaling. PCDH 19, however, specifically functions in neurological cell signaling, and thus, mutations to PCDH19 that alter function often cause epilepsy.

alpha fold screenshot

GRIN2A is a gene that helps code for the NMDA glutamate receptor, one of the ionotropic receptors. GRIN2A codes for the epsilon subunit of the NMDA receptor.

Epileptic treatment varies based off of severity and case. Generally, during a seizure, patients are treated at the moment with benzodiazepines, like lorazepam and diazepam. However, long-term, epileptics take anticonvulsant medications like phenobarbital and carbamazepine. Note- phenobarbital is a controlled substance! (True story. It is locked up behind a KEY in the veterinary clinic I intern at.)