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1. EPILEPSY

2.  EPILEPSY
• Epilepsy is defined by the occurrence of at least two
unprovoked seizures with or without convulsions (i.e. violent,
involuntary contraction of the voluntary muscles).
• A seizure results from an excessive discharge of cortical
neurons and is characterized by changes in electrical
activity as measured by the electroencephalogram (EEG).

3.  EPIDEMIOLOGY
• There are over 2.5 million people diagnosed with epilepsy every year.
• Epilepsy is one of the most common serious neurological disorders affecting about
65 million people globally.
• It affects 1% of the population by age 20 and 3% of the population by age 75.
• It is more common in males than females with the overall difference being small.
• Most of those with the disease (80%) are in the developing world.
• Epilepsy is usually present in childhood or adolescence but may occur for the first
time at any age. About 5% of the population suffers a single seizure at some
time.
• About 0.5-1% of the population have recurrent seizure epilepsy. About 70%
patients are well controlled with drugs (prolonged remissions) and 30%
epilepsy patients are at least partially resistant to drug treatments.

4.  ETIOLOGY
• Epilepsy has no identifiable cause in about half of those, with the condition.
• In about half the people with epilepsy the condition may be traced to
various factors.
• Genetic Influence: Some types of epilepsy, which are categorized by the
type of seizure experience, run in families. Certain genes may make a
person more sensitive to environmental conditions that trigger seizures.
• Head trauma: Head trauma that occurs due to a car accident or other
traumatic injury can cause epilepsy.
• Brain conditions: Brain conditions that result in damage to the brain, such as
brain tumors or strokes also can cause epilepsy. Stroke is a leading cause
of epilepsy in adults older than age 35.

5. • Infectious diseases: Infectious diseases, such as meningitis, AIDS and
viral encephalitis, can cause epilepsy.
• Prenatal injury: Before birth, babies are sensitive to brain damage that
could be caused by several factors, such as an infection in the mother, poor
nutrition or oxygen deficiencies. This brain damage can result in epilepsy
or cerebral palsy.
• Developmental disorders: Epilepsy can sometimes be associated with
developmental disorders, such as autism(inability to communicate &
interact) and neurofibromatosis(formation of tumors in the brain & spinal
cord).
• Stroke and other vascular diseases: Stroke and other blood vessel
(vascular) diseases can lead to brain damage that may trigger epilepsy.
• Dementia: Dementia can increase the risk of epilepsy in older adults.

6. Neonates (<1 month) Perinatal hypoxia, ischemia, Intracranial hemorrhage and trauma,
Acute CNS infection, Metabolic disturbances (hypoglycemia,
hypocalcemia, hypomagnesemia, pyridoxine deficiency), Drug
withdrawal, Developmental disorders and Genetic disorders.
Infants and children
(>1 month and <12
years)
Febrile seizures, Genetic disorders (metabolic, degenerative,
primary epilepsy syndromes), CNS infection, Developmental
disorders, Trauma and Idiopathic.
Adolescents (12–18
years)
Trauma, Genetic disorders, Infection, Brain tumor, Illicit drug use
and Idiopathic.
Young adults (18–
35 years)
Trauma, Alcohol withdrawal, Illicit drug use, Brain tumor and
Idiopathic.
Older adults (>35
years)
Cerebrovascular disease, Brain tumor, Alcohol withdrawal,
Metabolic disorders (uremia, hepatic failure, electrolyte
abnormalities, hypoglycemia), Alzheimer's disease and other
degenerative CNS diseases and Idiopathic.

7. TYPES OF EPILEPTIC SEIZURES7

8.  TYPES OF EPILEPSY
On the basis of the Intensity of seizures
• Grandmal Epilepsy (See tonic-clonic seizures)
• Petitmal epilepsy ( See absence seizures)
Other types:
• Juvenile myoclonic epilepsy: age groups- 8 to 20 years
• Benign partial epilepsy in childhood: patients below 12 years of age. It
starts with partial seizures which progresses into generalized tonic-clonic
seizures.
• Solitary parenchymal cysts: Single small cyst if present in the nervous
system causes the infection known as neurocysticercosis.
• Reflex epilepsy: The specific event or action that becomes responsible for
the attack of epilepsy like photosensitivity, hot water, cold water, or visual
stimuli.

9. CLINICAL MANIFESTATIONS & TYPES
 The clinical manifestation of a seizure will depend on the location of the
focus and the pathways involved in its spread.
• Seizures are divided into two main groups according to the area of the
brain in which the abnormal discharge originates.
• If it involves initial activation of both hemispheres of the brain
simultaneously, the seizures are termed ‘generalised’.
• If a discharge starts in a localised area of the brain, the seizure is termed
‘partial’ or ‘focal’.

10.  Generalised seizures
• Generalised seizures result in impairment of consciousness from the
onset
• Tonic seizures: Tonic seizures cause stiffening muscles. These seizures
usually affect muscles in back, arms and legs and may cause to fall
to the ground.
• Clonic seizures: Clonic seizures are associated with rhythmic, jerking
muscle movements. These seizures usually affect the neck, face and
arms.
• Myoclonic seizures: These usually appear as sudden brief jerks or
twitches of arms and legs.

11. • Tonic clonic convulsions:
• Often called ‘grand mal’ attacks, these are the commonest of all epileptic
seizures.
• Without warning, the patient suddenly goes stiff, falls and convulses, with
laboured breathing and salivation.
• Cyanosis and tongue biting may occur. The convulsion ceases after a few
minutes and may often be followed by a period of drowsiness, confusion,
headache and sleep.

12. • Absence attacks:
• Often called ‘petit mal’, these are a much rarer form of generalized
seizure.
• They happen almost exclusively in childhood and early adolescence.
• The child goes blank and stares; the fluttering of the eyelids and
flopping of the head may occur.
• The attacks last only a few seconds and often go unrecognized even by
the child experiencing them.
• Atonic seizures:
• These comprise a sudden loss of muscle tone, causing the person to
collapse to the ground. Recovery afterwards is quick.
• Partial or focal seizures

13. • Simple partial seizures:
• In these seizures, the discharge remains localised and consciousness is
fully preserved.
• What actually happens during a simple partial seizure depends on the
area of the discharge and may vary widely from person to person.
• Localised jerking of a limb or the face, stiffness or twitching of one
part of the body, numbness or abnormal sensations are examples of
what may occur during a simple partial seizure.
• If the seizure progresses with impairment of consciousness, it is termed a
complex partial seizure.

14. • Complex partial seizures:
• The person may present with altered or ‘automatic’ behaviour: plucking
his or her clothes and acting in a confused manner.
• Lip smacking or chewing movements, grimacing, performing aimless
activities. Most of these seizures originate in the frontal or temporal lobes
of the brain and can sometimes progress to secondarily generalized
seizures.

15. • Secondarily generalised seizures:
• These are partial seizures, either simple or complex, in which the
discharge spreads to the entire brain.
• The person may have a warning, but this is not always the case. The
spread of the discharge can occur so quickly that no feature of the
localised onset is apparent to the person or an observer, and only an
EEG can demonstrate the partial nature of the seizure.
• The involvement of the entire brain leads to a convulsive attack with the
same characteristics as a generalised tonic-clonic convulsion.

16. • Status epilepticus is defined as either continuous seizures lasting at least
for 5 minutes, or two or more discrete seizures between which there is
incomplete recovery of consciousness.
• Febrile seizures occur in upto 8% of children between 6 months and 6
years of age. Long term treatment or prophylaxis for simple febrile
seizures is not recommended.
• Unclassified epileptic seizures: Not all seizure types can be classified as
partial or generalized. This appears to be especially true of seizures that
occur in neonates and infants.

21. PATHOPHYSIOLOGY
• Epilepsy differs from most neurological conditions as it has no
pathognomonic lesion.
• A variety of different electrical or chemical stimuli can easily give rise
to a seizure in any normal brain.
• The hallmark of epilepsy is a rather rhythmic and repetitive hyper-
synchronous discharge of neurones either localised in an area of the
cerebral cortex or generalised throughout the cortex, which can be
observed on an electroencephalogram (EEG).

22. • Neurones are interconnected in a complex network in which each
individual neurone is linked through synapses with hundreds of others.
• A small electrical current is discharged by neurones to release
neurotransmitters at synaptic levels to permit communication with each
other.
• Neurotransmitters fall into two basic categories: inhibitory or
excitatory. Therefore, a neurone discharging can either excite or
inhibit neurones connected to it.
• An excited neurone will activate the next neurone whereas an
inhibited neurone will not.
• In this manner, information is conveyed, transmitted and processed
throughout the central nervous system.

23. PATHOPHYSIOLOGY
If neurones are damaged, injured or suffer a chemical or metabolic insult, a
change in the discharge pattern may develop.
↓
In the case of epilepsy, regular low-frequency discharges are replaced by
bursts of high-frequency discharges usually followed by periods of inactivity.
↓
A single neuron discharging in an abnormal manner usually has no clinical
significance.
↓
It is only when a whole population of neurons discharge synchronously in an
abnormal way that an epileptic seizure may be triggered.

24. This abnormal discharge may remain localised or it may spread to
adjacent areas, recruiting more neurones as it expands.
↓
It may also generalise throughout the brain via cortical and subcortical
routes, including collosal and thalamocortical pathways.
↓
The area from which the abnormal discharge originates is known as the
epileptic focus.

25. TESTS AND DIAGNOSIS
Physical examination
Neurological examination: A neurological examination looks at how
well brain and the rest of nervous system are functioning and may test
behaviour, motor abilities, mental function and other areas to diagnose
condition and determine the type of epilepsy.
Blood tests: There are a number of blood tests that may be recommended
to check for signs of infections, genetic conditions or other conditions
like electrolyte imbalances which may be associated with seizures.

26. Electroencephalogram (EEG): An electroencephalography test can help
to diagnose a seizure. These tests measure brain waves. Viewing brain
waves can help to diagnose the type of seizure.
Neuroimaging: Imaging scans such as a Computerized tomography (CT)
scan, Magnetic resonance imaging (MRI), Functional MRI (fMRI),
Positron emission tomography (PET) or Single-photon emission
computerized tomography (SPECT) also can help by providing a clear
picture of the brain. These scans allow to see abnormalities like blocked
blood flow or a tumor.
Neuropsychological tests: These tests are performed to assess thinking,
memory and speech skills. The test results help to determine which areas
of brain are affected.

27. TREATMENTS AND DRUGS
Goals of Treatment:
• The goals are to control or reduce the frequency and severity of seizures,
minimize side effects, and ensure compliance, allowing the patient to
live as normal a life as possible.
• The type of treatment prescribed will depend on several factors including
the frequency and severity of the seizures as well as the person’s age,
overall health, and medical history.

29.  Surgery:
• Surgery includes removal of the area of the brain causing the seizures.
Other therapies:
 Vagus nerve stimulation:
• The vagus nerve is stimulated to reduce the frequency and intensity of
seizures.
• This can be suitable for some people with seizures that are difficult to
control with medication.
 Ketogenic diet:
• A diet very high in fat, low in protein and almost carbohydrate free.
• This can be effective in the treatment of difficult-to-control seizures in
some children.

30. COMPLICATIONS
• Complications of complex partial seizures are easily triggered by
emotional stress.
• Patients may develop cognitive and behavioural difficulties like
memory loss, poriomania (wandering), violent behaviour etc.
• Complications associated with tonic- clonic seizures may involve injury
such as aspiration, skull or vertebral fractures, shoulder dislocation,
tongue or cheek injuries caused by biting & status epilepticus.

31. Questions
1. Define epilepsy. Explain the clinical features of different types of epilepsy
2. Explain different types of leprosy.
3. Describe the signs and symptoms of various forms of epilepsy
4. Describe the treatment of grand mal epilepsy in detail