This uploaded slide is to give simplified information to the needy guy z..I hope it will help you out.Do enjoy and plz do remember me in your duas..You can also mail me at Raashidmumtaz@gmail.com,if you need more or any other help..Thankx.
1. Department of clinical biochemistry.
University of kashmir.
Presentation on: Epilepsy
Presented by: Raashid Mumtaz.
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.
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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 i.e. If seizure originates from a
restricted part after then it may spread to the whole part.
B. Complex partial seizure. This type of seizure occurs in temporal
lobe of the brain.
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4. .The ictal phase of this type begins with automatism and motionless stare .
.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.
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. Consciousness is usually lost during this seizure.
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.
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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 also known as ictal cry due to
forcefulness of air expelled from lungs. However during the entire period
tongue may get bitten due to contraction of jaw muscle.
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.
Raashid Mumtaz ku 2015
. 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.
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Basicmechanismunderlyingseizures:Glutamate
hypothesis
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 GABA_B agonists, such as baclofen,
have been reported to exacerbate hyperexcitability and seizures.
Raashid Mumtaz ku 2015
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
Raashid Mumtaz ku 2015
.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.
Raashid Mumtaz ku 2015