Transcript Dr. Kristen Park presents an Epilepsy Overview

Epilepsy Overview
Kristen Park, M.D.
Children’s Hospital of Philadelphia
What is a seizure?
• Electrically: an abnormally
synchronous firing of neurons that
disrupts normal brain activity
• Clinically: has a variety of
manifestations from abnormal
sensations in a body part to
convulsions
Types of Seizures
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PARTIAL
Involving part of the
brain
Simple partial
Complex partial
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GENERALIZED
Involving the whole
brain
Absence
Tonic
Tonic-clonic
Atonic
Myoclonic
What causes seizures?
• Anything that irritates the brain can
result in seizures. They are often a
symptom of an underlying process. In
these cases they are considered provoked.
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Infections like meningitis or encephalitis
Trauma
Drugs
Electrolyte imbalances
Tumors and strokes
Fever
What causes seizures?
• In many cases, there is no discernible
immediate cause.
• Seizures in this instance are considered
unprovoked.
• In these cases there may be a genetic
basis, a malformation of cortical
development, or a remote injury to the
brain resulting in neurons that generate
seizures.
What is epilepsy?
• Epilepsy is the occurrence of more than
one unprovoked seizure.
• Can occur as a particular syndrome that
has a defined course and or treatment.
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Childhood absence epilepsy
Juvenile myoclonic epilepsy
Benign rolandic epilepsy
Lennox-Gastaut syndrome
The Single Seizure
• Normal children with normal EEGs
have a recurrence rate of 18% at 1y
and 24% at 2y
• An abnormal EEG increases the risk
to 42% at 1y and 52% at 2y
• Children with developmental
disabilities and an abnormal EEG have
an even higher risk
Epidemiology of Epilepsy
• Prevalence: total number of new and
existing cases of a disease
– 2.3-2.5 million people in the United States (1%)
• Incidence: number of newly diagnosed
cases each year
– 150,000-200,000 cases each year
– Mostly in young children and the elderly
Epidemiology
• There is an increased risk of epilepsy
in children with autistic spectrum
disorders with estimates ranging
from 7-42%
• 59% of newly diagnosed patients
have partial epilepsy
Diagnosis of Epilepsy
• Not as easy as you
might think!
• The black, white,
and gray zones.
Definitely a
seizure
Definitely not
a seizure
Seizure Mimics
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Syncope
Gastroesophageal reflux
Stroke
Tics or other dyskinesias
Psychiatric disorders
Parasomnias
Diagnosis of Epilepsy
• Epilepsy is a clinical diagnosis
– An abnormal EEG does not a diagnosis of
epilepsy make.
• Epileptiform abnormalities can be found in
approximately 2% of the population
• They can be found in 13-83% of children with autistic
spectrum disorders
• One study found them in 30% of children with ADHD
– A normal EEG does not exclude the diagnosis
of epilepsy
• Sampling
• Many people with epilepsy have normal EEGs between
seizures
What is an
EEG?
What is an EEG?
• Scalp recording of the cumulative activity of
the brain’s neurons
• Every person has a complement of brain wave
frequencies, organization, and patterns
associated with sleep or other activities.
• In many conditions, disruption of cortical
brain wave activity occurs resulting in
slowing, disorganization, and/or foci of
irritability (spikes – groups of neurons firing
together)
Diagnosis of Epilepsy
• What is a neurologist to do?
• Clinical judgement
– Characteristics of event: stereotyped, does not respect
situation or time, makes physiologic sense
• Provocative procedures
– Sleep deprivation
– Hyperventilation
• Video EEG
– The so called “gold standard” in diagnosis as it is able to
correlate the EEG with examination of the behavior of
interest
Treatment
• Medication should usually be instituted
after the second unprovoked seizure
• 40-80% of patients will respond to the
first anti-epileptic drug (AED)
• Of those who fail the first AED, 42% will
go on to remission with a second agent
Treatment
• Treatment goal should be “no seizures, no
side effects, and optimal quality of life”
• Medication is chosen based on several
factors:
– Type of seizure or epilepsy syndrome
– Coexisting medical conditions
– Dosing and monitoring
• Efficacy data not available for the
majority of situations
Anti-Epileptic Drugs
• A misnomer as these drugs do not
cure epilepsy but are designed to
prevent or suppress seizures
• Approximately 15 drugs on the
market, not all of which are available
in the United States
Anti-Epileptic Drugs
• Phenobarbital
• Phenytoin (Dilantin)
• Carbamazepine
(Tegretol)
• Oxcarbazepine
(Trileptal)
• Felbamate (Felbatol)
• Valproate (Depakote)
• Benzodiazepines
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Lamotrigine (Lamictal)
Topiramate (Topamax)
Zonisamide (Zonegran)
Levetiracetam (Keppra)
Ethosuximide (Zarontin)
Vigabatrin (Sabril)
Gabapentin (Neurontin)
Pregabalin (Lyrica)
Anti-Epileptic Drugs
• Many of these medications are also used to treat other
conditions like migraine, pain, depression, etc.
• Since they are designed to suppress the central nervous
system, neurologic side effects are commonly reported and
can include:
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Dizziness
Fatigue
Cognitive slowing
Etc.
• In addition, they may affect other organ systems within the
body that may need to be monitored
– Liver
– Kidneys
– Blood
Treatment
• 25% of children will not have good
control of seizures with medication
• In this case, alternative treatments
should be considered:
– Surgery
– Vagus nerve stimulator
– Ketogenic diet
Epilepsy Surgery
• Designed for specific situations in
which the focus of the seizures can
be identified and is amenable to
resection.
• Can be very effective if chosen
cautiously with seizure freedom
rates of 70-80% in children.
Vagus Nerve Stimulator
Vagus Nerve Stimulator
• Seizure freedom rate slightly less than
that of medications
• Often used as adjunctive therapy
• Efficacy takes up to two years
• Has both a tonic mechanism to decrease
seizure frequency as well as the ability to
stop seizures after onset by activating the
device with a magnet
Ketogenic Diet
• Known since biblical times that
seizures decrease during times of
fasting
– Matthew 17:15-21
“Lord, have mercy on my son”, he said.
“He has seizures and is suffering
greatly. He often falls into the fire,
or into the water. I brought him to
your disciples and they could not heal
him.”…Jesus replied…”Bring the boy
here to me…this kind does not go out
except by prayer and fasting.”
Ketogenic Diet
• Created a high fat, low carbohydrate, low
protein diet that physiologically resembles
this state
• True mechanism of action still debated
• Can be very effective in selected children
but is strict in its requirements
Is epilepsy a lifelong
condition?
• Not always.
• As the brains of children mature, they may
“outgrow” the tendency to have seizures.
• Anti-epileptic medication can be stopped
successfully in many cases after a duration
of seizure freedom (2-5 years).
• Under the best conditions, 69% of
children will be able to be taken off
medication without recurrence.
Seizure First Aid
• Place the child in a safe area away from sharp
objects, ledges, etc.
• Do not restrain the child.
• Turn the child onto his side so that he will not
choke on vomit or saliva
• Loosen tight clothing and remove glasses
• Do not place anything into his mouth
– It is not possible to swallow one’s tongue and this can
cause broken teeth and/or jaw
• Do not place your hand under his head
– The force of the seizure may break the fragile bones of
the hand
What can happen during
a seizure?
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Vomiting
Increased salivation
Urinary and bowel incontinence
Biting of the cheek or tongue
Cyanosis of the lips or fingers and shallow
breathing
• Post-ictal confusion, aggression, lethargy,
headache, etc.
When do I call 911?
• First time seizure
• In a child with epilepsy:
– Seizure >5 minutes
• Most seizures last 1-2 minutes
– Back to back seizures without recovery
in between
– Atypical or concerning features
References
• Seizures and Epilepsy in Childhood: A
guide for parents. Second Edition. John
M. Freeman, M.D., Eileen P. G. Vining, M.D.,
and Diana J. Pillas. The Johns Hopkins
University Press, Baltimore. 1997.
• Clinician’s Manual on Pediatric Epilepsy: A
guide to diagnosis, treatment, and future
directions. Dennis J. Dlugos, M.D.
Consensus Medical Press. 2006.
Resources
• www.efa.org
• www.epilepsy.com
• Your local Epilepsy Foundation
affiliate