Epilepsy Flashcards
(40 cards)
What is epilepsy?
Epileptic seizure can be defined as a sudden synchronous discharge of cerebral neurons causing symptoms or signs that are apparent either to the patient or to an observer
-Epilepsy is a tendency to recurrent, usually spontaneous epileptic seizures
Types of seizures?
-Can be classified as focal or general
Focal seizures?
-Occur in a focal region of the brain
Can be focal sensory or focal motor
General seizures?
Affect the whole brain
-Simultaneous involvement of both hemispheres, always associated with loss of consciousness or awareness
Types of epilepsy?
- Focal epilepsy
- Generalized epilepsy
What is focal epilepsy?
Type of epilepsy where there is a seizure focus (part of brain that doesn’t work properly) that can irritate the surrounding brain
-This focus can cause a focal seizure if the irritation stays in that are or it can cause a general seizure if the abnormal electrical activity hits a cortical network allowing it to spread throughout the brain
What networks do generalized epilepsy work on?
Cortical networks
- As soon as they occur they immediately propagate around the brain and generalized seizures occur
Focal epilepsy can cause?
Focal or generalized seizures
Generalized epilepsy can cause?
Only causes generalized seizures
Types of general seizure?
Absence Myoclonic Tonic Atonic Tonic clonic
Absence seizures?
- Loss of awareness and vacant expression <10 secs before returning abruptly to normal and continuing as though nothing happened
- Appears like they are day dreaming
Myoclonic seizures?
Jerk movements
Momentary brief contractions of muscles or muscle groups
Eg involuntary twitch of a finger or hand
Tonic seizures?
Consists of stiffening of the body not followed by jerking
Atonic seizures?
Sudden collapse with loss of muscle tone and conciousness
Tonic clonic seizures?
- Often no warning before these occur
- Initial tonic stiffening is followed by the clonic phase with synchronous jerking of the limbs reducing in frequently over about 2 minutes until convulsion stops
- May be incontinence when convulsions stop
- Period of flaccid unresponsiveness is followed by gradual return of awareness with confusion and drowsiness lasting 15 minutes to an hour or longer
Headache is common after
When do primary generalized epilepsy’s present?
As childhood and early adult life and account for up to 20% of all patients with epilepsy
Brain in primary generalised epilepsy?
Structurally brain is normal, ion channel and NT release abnormalities are hypothesised as causes
Primary generalized epilepsies include how many main syndromes?
3 main syndromes
- Childhood absence seizures
- Juvenile myoclonic epilepsy
- Monogenic epilepsy
Childhood absence epilepsy?
Absence seizures
Spontaneous remission by age 18 is usual
Juvenile myoclonic epilepsy?
- 10% of all epilepsies
- Typically myoclonic jerks start in teenage years
- Followed by generalized tonic clonic seizures
- Can occur with lack of sleep. alcohol or strobe light or flickering lights
Causes of monogenic epilepsies?
Single gene mutation in voltage gated channels
Focal seizures often indicate what?
Structural cause and detailed imaging is required to identify this
What do auras suggest?
Temporal lobe seizures
Causes include for epilepsy?
- Hippocampal sclerosis
- Genetic developmental disorders
- Trauma, hypoxia ad surgery
- Vascular disorders
- Infections
- Alcohol and drugs
- Immunological disorders
