Epilepsy Flashcards
Epilepsy is:
A chronic brain disorder that causes unprovoked, recurrent seizures. A seizure is a sudden rush of electrical activity in the brain. Epilepsy defined by any of the following conditions:
- At least two unprovoked (or reflex) seizures occurring more than 24 hours apart
- One unprovoked (or reflex) seizure and a probability of further seizures similar to the general recurrence risk after two unprovoked seizures (at least 60% over the next 10 years)
- Diagnosis of an epilepsy syndrome
Epilepsy is likened to an:
electrical storm in the brain – billions of connected neurones that short circuit and temporarily stop working. Can affect awareness, movement, sensation and consciousness depending on the severity.
Causes of epilepsy include:
- Genetic tendencies – passed down from one or both parents (inherited) or a genetic tendency that is not inherited, but is a new change in the person’s genes
- Structural (symptomatic) brain change – the brain not developing properly, or damage caused by a brain injury, infections like meningitis, a stroke or a tumour. Structural changes due to genetic conditions such as tuberous sclerosis, or neurofibromatosis, which can cause growths affecting the brain.
Pathology of a seizure:
For seizure activity not to occur in a healthy brain, there needs to be a proper balance between inhibitory and excitatory neurons. If there is an imbalance of excitatory neurons vs. inhibitory neurons seizures will occur, i.e. if there is not enough GABA (inhibitory neurotransmitter) being released or too much glutamate (excitatory neurotransmitter) released, too much excitation will occur leading to seizure activity
Seizures tend to last for:
a few seconds up to a few minutes, majority happen without warning and vary significantly in frequency, some happen only at night, morning.
Epileptic seizures can result in:
many physical injuries
Types of seizures include:
Seizures vary depending on where in the brain they are happening - two main types are generalised (affecting the whole brain) and focal/partial (affecting just one part of the brain):
- Focal seizures – focal onset aware seizures (also called simple partial seizures), focal impaired awareness (also called complex partial seizures) and focal to bilateral tonic clonic
- Generalised seizures - tonic-clonic seizures (formerly known as grand mal seizures), absence (petit-mal) seizures, atonic (drop attacks) seizures, myoclonic seizures, tonic seizures, and clonic seizures.
Stages of seizures include:
Prodromal, Aura, Ictus, Post ictus
Prodromal is:
when symptoms start to appear prior to the seizure, i.e. depression, anger, issues sleeping, anxiety, GI and urinary issues. Can start days before seizure
Aura is:
eferred to as warning sign before seizure but not everyone gets them. More common in focal seizures or tonic-clonic seizures and happens within seconds or minutes. Seen as: altered vision/hearing, anxiety or dread, déjà vu, weird taste/smell, dizzy, speech, visual spots, inability to speak.
Ictus is:
Seizure time: Usually 1-3 mins, if > 5 mins or starts to have back-to-back seizures = status epilepticus - requires immediate medical treatment.
Post ictus is:
time taken for the brain to recover: Can be immediate (absence) or take hours-days (tonic-clonic). Often symptoms include: very tired, confused, headache, injury (tongue, cheek, body)
Tonic-clonic is when:
the patient loses consciousness and the patient may experience an aura (warning sign) before the seizure. Then the patient will experience: tonic episode: body stiffens (may bite the inside of the cheek or tongue, cry out, and experience apnea), and this is followed by the clonic episode, which is recurrent jerking of the extremities. The patient may have incontinence as well. The post ictus stage can take hours to days, and the patient may report feeling very tired, sore, have a headache etc.
Absence is:
most common in children. Hallmark is staring (patient may appear to be daydreaming). This type of seizure is very short and may go undetected by others. The post ictus stage is immediate recovery but won’t remember event.
Atonic is:
drop attacks: this is complete loss of muscle tone. The patient will suddenly lose muscle tone and is at risk for head injury. Patients should be advised to wear a helmet with this type of seizure.