(2) Much research stil needs to be done in determing is “mechanisms” are always “ causes” – membrane function, receptor function, neuronal networks – all trigger siezures and thereore epilepsie, but are these the causes themselves, or just the trigger?

(10) ETIOLOGY -- “the study of the causes of diseases”
“the cause or origin of a disease”
“The study of causation”
“any study of causes, causation, or causality”

“Most of the epilepsies are influenced by variation at several or multiple
genes.” P31

(5)” There is good evidence that acquired epilepsies are influenced by genetic effects,
and less powerful evidence that idiopathic epilepsies are modified by acquired factors”p32
^ this means that epilepsies cause by outside factors are often reemphasized by genetic factors, but epilepsies caused initially by genetics are not altered much by outside factors

(5)“Epilepsies in which the sole aetiology is a complex genetic predisposition are common and account for a minimum 50% of all epilepsy” p32

---“One type is benign familial neonatal convulsions (bfnc), a
dominantly inherited disorder of newborns kcnq2 and kcnq3 are two homologous k+ channel
subunits that can combine to form heterothermic channels. Loss-of-function mutations in
kcnq2 and kcnq3 potassium channel genes can lead to benign familial neonatal convulsions
(bfnc)” p35 ----mutations of these channels often cause generalized epilepsy

The main etiologies, or causes, of acquired epilepsy’s might act through these abnormal ion channels as a common pathway (this is a quote)p35

(5)Genetic mutations that cause epilepsy often have to do with ion channels, K+ and Na+, ion channel abnormalities predominate---“In several of these syndromes genetic defects have been identified, with the vast majority of these affecting ion channels” p32 – see chart--- water transport functionality is also vital in maintaining ion homeostasis is brain, mediated by specific water channels like AQP4

(5)“Ion channel dysfunction is central to the genetic human
epilepsies. There is increasing evidence that mutation in the genes encoding ion channels and
drug transporters have an important role in epileptogenesis.” P36

(5)Mutations have been discovered in ion channels, especially K+ and Na+, preventing the flow of these ions, possibly creating problems with neurotransmissions. ---- comples relationship between ion channels and epilepsy – see quote

(11) EPILEPSY -- “a disorder of the nervous system, characterized either by mild, episodic loss of attention of sleepiness (petit mal) or by severe convulsions with loss of consciousness”

(7)• Symptoms
o Epilepsy can affect brain proceses as it is caused by abnormal activity in brain cells
 Confusion, jerking of arms and legs, loss of consciousness
o Depends on typs of seizure person has

(7)• Usually focal or generalized
o Focal is abnormal acitivity in just on part of brain, also called partian siezures
 Simple partial siezures – no loss of consciousness, may alter emotions or senses, involuntary jerking
 Complex (dyscognitive)- change in state of consciousness

(3) Lower-level tumors, surprisingly, cause more aggressive epilepsy and stronger seizures (DNETs), gangliogliomas, and other low grade gangliogliomas).////more aggressive tumors have generally a lower incidence of epilepsy

(3)Head trauma and post-trauma siezures DO NOT always mean epilepsy. These “spells” might just be associated with PTSD

(3) The risk of developing post traumatic epilepsy increases at age 65 or older, presence of a brain contusion, linear depressed skull fracture, and if subject has lost consciousness for more than 24 hours

“The increased risk, however, is
limited to those who are diagnosed with moderate or severe
civilian traumatic brain injury, which comprises almost 5% of
all cases of head trauma. In people who are under the age of
35, traumatic brain injury increases the risk for both generalized
tonic–clonic seizures and complex partial seizures” p233

Risk of developing epilepsy post-trauma is greatest in the first two years after incident

(4) 30-40% of epileptics have seizures that cannot be wholly controlled by medications

(4) “Dysembrioplastic Neuroepithelial Tumor
(DNET) is a congenital, benign tumor due to a developmental
abnormality of certain embryonic cells
of the brain, frequently associated with epilepsy.”

• (4) DNET definition, see quote -- Dysembrioplastic Neuroepithelial Tumor
o Lesions of these tumors typicall cause complex partial seizures before the age of 20 in individuals who re otherwise neurological normal.
o At least 80% of patients are deemed seizure-free after such a tumor is removed

o (9) Sudden, unexpected storm of electricity is active in the brain. The neurons that transmit electrical impulses and message to each other get confused and overloaded.

(9)o Might be in one spot of brain (partial) or all over (general)

(9) • Many different types of seizure, cause by differences in how electrical storms affect brain activity

(9) • Epilepsy Common?
o 1 in 133 people have it in some capacity
o 120,000 new cases each year in USA
o Can affect anyone, mostly under 20 and over 60 though
o More common in developing country because of brain infections, problems in childbirth, and poor nutrition…. all ENVIRONMENTAL FACTORS

(9) o Not like any other disease, like flu or chicken pox – not one singular specific cause. Many contributing factors

(9)  Head injuries – brain damage may lead to epilepsy as electrical connections and neurons in brain are damaged – “The brain tries to repair itself after an injury, but sometimes mixes up wiring, making odd connection between neurons in the brain. This can cause the unusual electrical messages that occur in the brain during seizures.” P26

(9)  Other illnesses – most common are stroke (blood to brain is cut off) and brain tumors (growth in brain) – these more common in elderly people

(9) • Triggers – not exactly causes but factors outside one’s self that might trigger epileptic seizures
o Lack of sleep is major problem
o Alcohol, bc interferes with medicines you take – also effects are more potent bc of meds
o Stress – neuron become overloaded and too active, or stress deprives of sleep, both causing seizures
o Photosensitivity – flashing lights or watching tv, overstimulation of brain activity that may cause storm of electrical impulses

(5) “At the same time many brain
malformations like cortical dysplasia, hippocampus sclerosis and other brain injuries may
have a role in causing epilepsy”p36

(15) • Anoxia – lack of sufficient oxygen to the brain – results in brain damage (lesions) that could later cause epilepsy

(14)
o More likely in adults, either secondary (carried by blood from another site to the brain) or primary (originally in brain)

(14) o Primary tumors that cause epilepsy don’t originate in nerve cells of brain, but in supporting cells between nerve cells and the covering membranes of the brain
 These tumors called gliomas and meningioma’s
 Affect epilepsy because disturbs connections between brain cells, (storms of electricity) that cause epileptic seizures

(15) in regards to scars left by diseases -- “Acute abscesses can certainly cause epileptic seizures, but, even if successfully treated by drainage and by antibiotics, further seizures may arise from the scar. In an attempt to avoid this, many surgeons now excise totally the capsule of the abscess rather than simply aspirate the pus.”

(15) “Parasites can also cause epilepsy. The pork tapeworm Taenia solium may cause epilepsy if the cystic stage of the tapeworm, usually found in pigs, occurs in the muscles and brain of man. In developing countries, calcified cysts are found in the brains of many of the rural population and this disorder, cysticercosis, and tuberculosis accounts for a lot of the greater incidence of epilepsy in such populations. The dog tapeworm Toxocara has also been incriminated in the development of epilepsy, though with less certain evidence. Toxoplasmosis, possibly acquired through infection in utero from domestic animals is certainly associated with seizures.”

(15) o Can scar brain tissue, disturbing connections and possibly leading to later epilepsy

(15) o Sturge-Weber syndrome – malformation of blood vessels in upper part of face, brain doesn’t get enough blood leading to seizures
o Disorders of migration of nerve cells during fetal development – these end up in wrong place, on wrong layer of brain, or don’t have good or correct connections
o These are likely genetic in basis

(15) o Sometimes a recessive gene creates a disorder of the metabolism of the brain, fatty substances called lipids are important part of membranes surrounding nerves cells. When these form incorrectly, may lead to paroxysmal discharge of never cells, resulting in an epileptic seizure

(15) o Often parents or siblings of patient with primary generalized epilepsy have similar EEG readings, but just don’t discharge with same magnitude as patients does when he/she has a seizure – or has different combination of genes that the person with epilepsy which allow these discharges to be suppressed