Epilepsy is a brain disorder characterized by seizures caused by disturbed electrical activity in the brain. Seizures can be partial, involving one area of the brain, or generalized, involving both sides. Common types of generalized seizures include absence seizures, grand mal seizures, myoclonic seizures, and atonic seizures. The underlying mechanism of seizures involves excessive glutamate signaling and imbalance between excitatory and inhibitory neurotransmission. Diagnosis involves EEG and imaging scans while treatment focuses on anticonvulsant drugs that block sodium channels, enhance GABA activity, or slow sodium inactivation.

1. Department of clinical biochemistry.
University of kashmir.
Epilepsy
ameendelina@gmail.com

2. EPILEPSY
.Epilepsy is a brain disorder in which a fit
occurs due to disturbance in the electrical
activity of the brain.
.It is characterized by loss of consciousness
which is often accompanied by repeated jerky
movements called convulsion.

3. Different types of seizures
1.Partial seizure : Its caused by electrical discharge restricted
to limited part of cortex of one cerebral hemisphere.
.Types of partial seizure
A. Simple partial seizures: cause motor, sensory, autonomic,
or psychic symptoms
.Consciousness is not lost during partial seizure.
. Shows jacksonian march.
B. Complex partial seizure. This type of seizure occurs in
temporal lobe of the brain.

4. .The behavioural arrest is usually accompanied by
automatisms.
. Automatisms may consist of very basic behaviours such as
chewing, lip smacking, Crying ,laughing .
C. Partial Seizures with Secondary Generalization
. Partial seizures can spread to involve both cerebral
hemispheres and produce a generalised seizure.
. Consciousness is usually lost during this seizure.

5. Epilepsy

6. .These seizures involve both sides of the brain.
.There is loss of consciousness and a postictal phase after the
seizures.
Types of generalised seizure
A. Absence seizures (Petit mal)
.These seizures involves brief, altered loss of consciousness.
.Persons posture is maintained during the seizure.
.The mouth or face may twitch or the eyes may blink rapidly.
.No convulsion.
B. Grand mal seizure
.Characterized by sudden loss of consciousness followed by
convulsion. Two phases Tonic and clonic.
2.Generalised seizures

7. tonic phase followed by a clonic period (contraction and relaxation of the
muscles) and postictal period.
.Patient may express loud moan or loud scream.
C. Myoclonic seizures
. This type refers to quick movements or sudden jerking of a group of
muscles.
.These seizures tend to occur in clusters.
D. Atonic seizure
.With this seizure , there is sudden loss of muscle tone and persons may fall
from standing positions.
.During this seizure , the person is limp and unresponsive.
.No post ictal confusion.
. The body ,arms and legs will contract and straighten out during

8. .Glutamate is the major excitatory neurotransmitter in the brain.
.It has an ionotropic receptor called NMDA.
.It is permeable to Na+ and K+ ions.
.NMDA receptor also has Ca++ channels that is blocked by Mg ions in the resting
state.
.During depolarisation Mg + is displaced and channel becomes permeable to ca++.
.Influx of ca++ further causes depolarisation and is also thought to contribute ca
++ mediated neuronal injury under conditions of excessive neuronal activation.
Basicmechanismunderlyingseizures:Glutamate
hypothesis

9. Glutamate-Glutamine cycle

10. GABA: Inhibitory role

11. .GABA-A receptors are permeable to Cl- ions; upon
activation Cl- influx hyperpolarizes the membrane and
inhibits action potentials. Therefore, substances which are
GABA-A receptor agonists, such as barbiturates and
benzodiazepines, are well known to suppress seizure activity.
.GABA-B receptors are associated with opening of K+
channels leading to a hyperpolarizing current. Certain GABAB
agonists, such as baclofen, have been reported to exacerbate
hyperexcitability and seizures.

12.  The causes of most cases of epilepsy is unknown , although some people
develop epilepsy as the result of:
 Brain injury
 Brain tumour
 Drugs
 Alcohol
 Hypoglycemia
.Symptoms
General symptoms of a seizure are:
 Jerking movement of the arms and legs
 Loss of consciousness
 Appearing confused or in a haze
 Periods of rapid eye blinking and staring
.Causes

13.  Epilepsy is often diagnosed by EEG ,PET scan etc.
.Treatment
Anticonvulsants are given:
Anticonvulsants can be divided into large group based on their mechanism:
.Blockers of repetitive activation of sodium channel.
Phenytoin , Carbamazepine
.Enhancers of slow inactivation of sodium channel.
Cosamide , Rufinamide
.GABA A receptor enhancers phenobarbital.
.Diagnosis

14. .people who are not benefited or whose seizures are not being
well controlled with seizure medication may benefit from a
procedure called vagus nerve stimulation.

15. Thank you.