Epilepsy

2. Definition
0 Epilepsy is a brain disorder in which clusters of nerve cells, or
neurons, in the brain sometimes signal abnormally.
0 Neurons normally generate electrochemical impulses that act on
other neurons, glands, and muscles to produce human thoughts,
feelings, and actions.
0 In epilepsy, the normal pattern of neuronal activity becomes
disturbed, causing strange sensations, emotions, and behavior, or
sometimes convulsions, muscle spasms, and loss of consciousness.
7/23/2013 2

3. Epidemiology
0 More than 2 million people in the United States -- about 1 in 100 --
have experienced an unprovoked seizure or been diagnosed with
epilepsy.
0 For about 80 percent of those diagnosed with epilepsy, seizures
can be controlled with modern medicines and surgical techniques.
0 However, about 25 to 30 percent of people with epilepsy will
continue to experience seizures even with the best available
treatment.
7/23/2013 3

4. Aetiology
0 Epilepsy is a disorder with many possible causes. Anything that disturbs
the normal pattern of neuron activity -- from illness to brain damage to
abnormal brain development -- can lead to seizures.
0 Epilepsy may develop because of an abnormality in brain wiring, an
imbalance of nerve signaling chemicals called neurotransmitters, or
some combination of these factors.
0 Researchers believe that some people with epilepsy have an abnormally
high level of excitatory neurotransmitters that increase neuronal activity,
while others have an abnormally low level of inhibitory
neurotransmitters that decrease neuronal activity in the brain. Either
situation can result in too much neuronal activity and cause epilepsy.
7/23/2013 Causes 4

5. Continuation………….
0 Neurotransmitters that plays a role in epilepsy is GABA, or gamma-
aminobutyric acid, which is an inhibitory neurotransmitter.
0 In some cases, the brain's attempts to repair itself after a head
injury, stroke, or other problem may inadvertently generate
abnormal nerve connections that lead to epilepsy.
0 Abnormalities in brain wiring that occur during brain
development also may disturb neuronal activity and lead to
epilepsy.
7/23/2013 Causes continuation 5

6. Continuation…………….
0 The cause is unknown in 70% of cases
0 Brain Trauma (ex. injury, stroke)
0 Brain Lesions (ex. tumors)
0 Poisoning (ex. lead)
0 Infections of the brain (ex. meningitis, encephalitis, measles)
0 Brain injury at birth
0 Genetic causes
0 Abnormal brain development
0 Chronic alcohol/ drug abuse
7/23/2013 Causes continuation 6

7. Classification
0 There are many different types of seizures, some that affect the whole
brain (generalised) and some that affect part of the brain (partial).
0 Common generalised seizures
Tonic-clonic seizures (sometimes called grand mal)
Absence seizures (sometimes called petit mal)
Myoclonic seizures
Atonic seziure
Intractable seziure
0 Common partial seizures
Simple partial seizures
Complex partial
Secondary generalisation.
Status epilepticus.
7/23/2013 7

8. Tonic-clonic seizures (sometimes called grand mal)
0 The person loses consciousness, goes stiff and falls to the ground.
Sometimes they appear to cry out.
0 The skin (particularly around the mouth and under the finger
nails) may appear blue in colour.
0 There can be loss of bladder or bowel control. The limbs jerk as
the muscles contract and relax in quick succession.
0 The person may bite their tongue and the inside of their cheeks.
Slowly they will regain consciousness, but may well be groggy or
confused.
0 Very often, the person remains sleepy and may have a headache
and aching limbs.
7/23/2013 Tonic-clonic seziure 8

9. Absence seizures (sometimes called petit mal)
0 During an absence seizure the person is momentarily unconscious.
0 It may appear that they are daydreaming or switching off.
However, they are totally unaware of what is happening around
them and they cannot be woken up.
0 Absence seizures are most common in childhood. Absence
seizures usually begin between ages 4 and 14. The children who
get them usually have normal development and intelligence.
0 And nearly 70% of cases, absence seizures stop by age 18.
7/23/2013 Absence seizures 9

10. Myoclonic seizures
0 These are sudden jerks.
0 They can affect the whole body, but are usually restricted to one
or both arms and sometimes the head.
0 The person is not conscious, but the seizure is so brief that the
person appears to remain fully conscious.
0 "Myo" means muscle and "clonus" (KLOH-nus) means rapidly
alternating contraction and relaxation—jerking or twitching—
of a muscle.
7/23/2013 10

11. Atonic seizures
0 Atonic seizures cause a sudden loss of muscle tone.
0 Motor symptoms include head drops, loss of posture, or sudden
collapse.
0 Because they occur without warning, atonic seizures can result in
injuries to the head and face. Protective headgear is sometimes
used by children and adults.
0 Other names include drop attacks, astatic or akinetic seizures.
7/23/2013 11

12. Intractable Seizures
0 Seizures of any kind that do not respond to medications.
0 Twenty percent of people with epilepsy have seizures that are
resistant to medication, otherwise known as refractory epilepsy.
7/23/2013 12

13. Simple partial seizures
0 The person remains fully conscious, but they are unable to stop or
control the seizure.
0 Examples of symptoms are the movement of a limb; tingling;
experiencing a non-existent smell or taste; going pale; sweating; or
experiencing a churning feeling in the stomach.
0 Other symptoms can be feelings of fear, panic, sadness or happiness.
0 When seizures occur in the part of the brain responsible for vision,
people can see flashing or balls of light, or experience temporary absence
of vision.
7/23/2013 13

14. Complex partial
0 The person is only partly conscious and although it may appear
that they are fully aware of what they are doing, this isn’t the case.
0 Examples of symptoms are chewing and swallowing, fumbling
with buttons, repeatedly scratching the head or searching for an
object. Some people may remove items of clothing.
0 Sometimes the seizures can involve complex body movements,
apparently strange behaviour or actions of a sexual nature.
7/23/2013 14

15. Secondarily generalized
0 The generalized, convulsive phase of these seizures usually lasts no more than a
few minutes, the same as primary generalized seizures.
0 The preceding partial seizure is usually not very long. Sometimes this part is so
brief that it is hard to detect.
0 These seizures are called "secondarily generalized" because they only become
generalized (spread to both sides of the brain) after the initial or "primary"
event, a partial seizure, has already begun.
0 They happen when a burst of electrical activity in a limited area (the partial
seizure) spreads throughout the brain. Sometimes the person does not recall the
first part of the seizure. These seizures occur in more than 30% of people with
partial epilepsy.
They can affect people of all ages who have partial seizures.
7/23/2013 15

16. Status Epilepticus
0 Most seizures end after a few minutes. If seizures are prolonged,
or occur in a series,there is an increased risk of status epilepticus, a
true life threatening emergency.
0 Status epilepticus is usually defined as 30 minutes of
uninterrupted seizure activity or repeat seizures without a return
to consciousness.
0 The Epilepsy Foundation advises parents and the public to call for
emergency assistance
0 when a convulsive seizure lasts for more than five minutes without
signs of stopping,
or
0 when successive seizures last more than five minutes without a
return to consciousness.
7/23/2013 16

17. Pathophysiology
0 Nerve impulse propagates in the brain in a synchronous manner and for
that the electrical potential reaches to zero. Any type of process which
damages or cause irritation to the grey matter of the brain may cause
activation or inactivation of neurons causes by unknown mechanism.
0 This leads to sudden, excessive, synchronous discharge which results in
an electrical potential. If the discharge remains localized it results in
partial seizures or it may spread and involve the entire cerebrum causing
generalized seizures.
0 Imbalance of excitatory transmitters such as G-amino butyric acid and
selective central nervous system, calcium channel blockers may be
involved in the seizure disorders.
7/23/2013 17

18. Continued…..
0 The excessive neuronal disorderly discharge involving in the entire
brain results in loss of consciousness, disturbances in sensation
and conclusive movements. After peak of seizures there is decrease
in frequency of neuronal discharge. It leads to the end of seizures .
0 The seizure may be ending due to loss of cerebral energy reserves,
local tissue anoxia, accumulation of toxic metabolites of neuronal
metabolism and inhibitory neuronal feed back mechanisms.
7/23/2013 18

19. Signs and symptoms
0 "Blackouts" or periods of confused memory
0 Episodes of staring or unexplained periods of unresponsiveness
0 Involuntary movement of arms and legs
0 "Fainting spells" with incontinence or followed by excessive fatigue
0 Odd sounds, distorted perceptions, or episodic feelings of fear that
cannot be explained.
0 Strange sensations
0 Visual hallucinations
0 Emotional changes
0 Muscle spasms
0 Convulsions
0 Other symptoms, depending on where in the brain the seizures begin.
7/23/2013 Signs and symptoms 19

20. Diagnosis
0 EEG
0 MRI
0 BLOOD TESTS
7/23/2013 20

21. Diagnosis
0 An EEG, or electroencephalogram, is a test that can help
diagnose epilepsy
0 During an EEG, the electrical signals of the brain are recorded. This
electrical activity is detected by electrodes, or sensors, placed on
the patient's scalp and transmitted to a machine that records the
activity.
0 Electrical signals produced by the brain neurons are picked up by
the electrodes and transmitted to a machine, where they produce
separate graphs on moving paper recorded in ink or on a computer
screen.
7/23/2013 21

22. Continued……
0 CT and MRI scans reveal the structure of the brain, which can be useful
for identifying brain tumors, cysts, and other structural abnormalities.
An adapted kind of MRI called functional MRI (fMRI) can be used to
monitor the brain's activity and detect abnormalities .
0 SPECT (single photon emission computed tomography) is a relatively
new kind of brain scan that is sometimes used to locate seizure foci in the
brain.
0 Doctors may use an experimental type of brain scan called a
magnetoencephalogram, or MEG.
0 MEG detects the magnetic signals generated by neurons to allow doctors
to monitor brain activity at different points in the brain over time,
revealing different brain functions.
7/23/2013 22

23. 0 Doctors also are experimenting with brain scans called magnetic
resonance spectroscopy (MRS) that can detect abnormalities in the
brain's biochemical processes, and with near-infrared
spectroscopy, a technique that can detect oxygen levels in brain
tissue.
0 These blood samples are often screened for metabolic or genetic
disorders that may be associated with the seizures. They also may
be used to check for underlying problems such as infections, lead
poisoning, anemia, and diabetes that may be causing or triggering
the seizures.
7/23/2013 diagnosis 23

24. Non-pharmacological
treatment
0 First Aid for Generalized Tonic-Clonic Seizures:
0 Stay calm, note time seizure began and duration of event
0 Lay person down and turn on left side
0 Place something soft under head
0 Clear objects away from jerking extremities
0 Loosen tight clothing around the neck
0 Protect head and remove glasses
0 Do not restrain
0 Provide privacy if possible
0 Stay with the person until the seizure ends and a full return to
consciousness is observed
7/23/2013 24

25. Tonic-Clonic Seizure in a Wheelchair:
0 Do not remove from wheelchair unless absolutely necessary
0 Secure wheelchair to prevent movement
0 Fasten seatbelt (loosely) to prevent person from falling out of
wheelchair
0 Protect and support head
0 Ensure breathing is unobstructed and allow secretions to flow
from mouth
0 Pad wheelchair to prevent injuries to limbs
0 Follow relevant seizure first aid protocol
7/23/2013 25

26. Treatment (pharmacologically)
0 Classification:
0 hydantoins : phenytoin
0 Barbiturates: phenobarbitone
0 Iminostilbene: carbamazepine
0 Succinimide: ethosuximide
0 GABA transaminase inhibitiors: valproic acid
0 Benzodiazepines: diazepam
0 GABA analouges: vigabatrin.
7/23/2013 26

27. Phenytion
0 Mechanism of action
blocks sodium channels in activated state
blocks high frequency firing
delays recovery of sodium channels from inactivation
stabilizes the neuronal membrane
inhibits generation of action potentials
inhibits spread of seziures
0 Adverse effects
epigastric pain
ataxia
anorexia
0 Drug interactions
cimetidine and chlormphenicol inhibit metabolism of phenytoin.
0 Dose 20mg/kg
7/23/2013 27

28. Carbamazepine
0 It’s a tricyclic compound
0 Commonly used as antiepileptic drugs
0 Mechanism of action: similar to phenytion
0 Useful in treating trigeminal neuralgia and glosso-pharyngeal
neuralgia
0 Found to be beneficial in mood disorders and has mild anti diuretic
effects
0 Adverse effects : vertigo ,blurring of vision ,dizziness.
0 Dose : 200-400mg TDS
0 Drug interaction : its an enzyme inducer enhance its own
metabolism and of other drugs like phenytoin , valproic acid.
7/23/2013 28

29. Ethosuximide
0 Its an succinimde
0 It raises the seizure threshold
0 Mechanism of action : it reduces the low threshold calcium
currents (T-currents) in the thalamic neurons which are
responsible for absence seziures.
0 Advrse effects: lethargy ,euphoria ,leukopenia , urticaria .
7/23/2013 29

30. Valproic acid
0 It ‘s an salt of sodium valproate
0 Effective in antiepileptic drugs for absence , partial and
generalised seziures.
0 Mechanism of action :
increased synthesis of GABA by increased activity of GABA
synthesase enzyme
decreasing the metabolism of GABA by inhibiting GABA
transaminase enzyme .
blocks sodium channels
decreases the low threshold calcium( t-currents in the
thalamus)
0 Adverse effects: tremors ,rashes, alopecia.
0 Drug interactions : it inhibits the clearance of lamotrigine
7/23/2013 30

31. 0 Diazepam is a drug of choice in status epilepticus and febrile
convulsions
0 Lorazepam may be used in place of diazepam dose : 0.1mg/kg IV
0 Clonazepam is a potent antiepileptic useful in absence and
myoclonic seizures
0 Vigabatrine is an GABA analouge which acts by irreversibily
inhibiting the enzyme GABA transminase thereby raising brain
GABA levels
0
0 Lamotrigine is abroad spectrum antiepileptic activity . Prolongs the
activation of sodium channels and also inhibits the release of
excitatory amino acids like glutamate dose:50-300mg/day
7/23/2013 31

32. 7/23/2013 32