Epilepsy

Question 1

what is epilepsy

Answer 1

An epileptic seizure can be defined as: a sudden synchronous discharge of cerebral neurones causing symptoms or signs that are apparent either to the patient or an observer.
Epilepsy is an ongoing liability to recurrent epileptic
seizures.

Question 2

epilepsy epidemiology

Answer 2

it is common with 444000 in the UK. most cases start before 20 and after 60.

Question 3

what are the different types of epileptic seizure

Answer 3

a partial (FOCAL) seizure - caused by electrical discharge restricted to a limited part of the cortex of one cerebral hemisphere.
they are further divided if whether there is a loss of awareness or not.
- simple partial seizures - without loss of awareness e.g. one limb jerking (jacksonian seizure)
- complex partial seizures - with loss of awareness e.g. temporal lobe seizures

GENERALIZED SEIZURES - there is a simultaneous involvement of both hemispheres, always associated with loss of consciousness or awareness.

a partial seizure may spread after a few seconds due to failure of inhibitory mechanisms, causing a secondary generalized seizure.

Question 4

what are the generalized seizure types

Answer 4

typical absence seizures - almost invariably begins in childhood. there is a loss of expression and awareness before abruptly returning to normal <10 seconds.

generalized tonic-clonic seizures:
- prodrome - there is often no warning or there may be aura prior to secondary generalised seizure.
- tonic-clonic phase - an intial tonic stiffening is followed by the clonic phase with synchronous jerking of the limbs, reducing in frequency over about 2 minutes until the convulsion stops.
- post-ictal phase: a period of flaccid unresponsivness is followed by gradual return of awareness.

Question 5

partial seizure types

Answer 5

simple partial seizure - JACKSONIAN, these originate within the motor cortex, Jerking typically begins on one side of the mouth or in one hand, sometimes spreading to involve the entire
side

complex partial seizures - These usually arise from the temporal lobe (60%) or the frontal lobe, preceding aura and often rising epigastric sensation and nausea with a wide variety of possible psychic phenomena.

Question 6

what the causes of epilepsy

Answer 6

primary generalised - Presenting in childhood and early adult life, these account for up to 20% of all patients with epilepsy. The cause is thought to be polygenic with complex inheritance. The brain is structurally normal but abnormalities of ion channels influencing neuronal firing, abnormalities of neurotransmitter release and synaptic connections are probably the underlying molecular pathological substrates

symptomatic and localization-related epilepsy - Almost any process disrupting the cortical grey matter can
cause epilepsy. This is usually localization-related epilepsy with partial seizures arising from the affected area of cortex with or without secondary generalized seizures

Hippocampal sclerosis - This is a major cause of epilepsy. Hippocampal sclerosis (damage with scarring and atrophy of the hippocampus and surrounding cortex) is the main pathological substrate causing temporal lobe epilepsy and the leading cause of localization-related epilepsy.

genetic and developmental disorders - Over 200 genetic disorders include epilepsy among their
features, e.g. tuberous sclerosis.