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باطنية
د. محمد الشيخ عيسى

عدد الاوراق (7)

8/5/2013

Epilepsy

Definitions
● Seizure: the clinical manifestation of an abnormal, excessive, hypersynchronous electrical discharge
. of a group of cortical neurons of the cerebrum
● Epilepsy: two or more recurrent seizures unprovoked by an acute systemic or neurologic insult
● Seizure disorder: frequently employed to avoid the term epilepsy and for recurrent seizures where each is provoked by an identifiable stimulus
● Seizure: the clinical manifestation of an abnormal, excessive, hypersynchronous electrical discharge
. of a group of cortical neurons of the cerebrum
● Epilepsy: two or more recurrent seizures unprovoked by an acute systemic or neurologic insult
● Seizure disorder: frequently employed to avoid the term epilepsy and for recurrent seizures where each is provoked by an identifiable stimulus
Seizures
● Incidence: approximately 80/100,000 per year
● Lifetime prevalence: 9% (1/3 benign febrile convulsions)
epilepsy
● Incidence: approximately 45/100,000 per year
● Point prevalence: 0.5 – 1%


Etiology of Epilepsy
Idiopathic
Secondary
In uterus –––––> rubella At birth –––––> infection
birth trauma
Brain injury or infection
Cerebral tumors or vascular diseases

Classification of Epileptic Seizures

Partial (or focal) Seizures
Primary Generalize Seizures
Status Epilepticus

Frequency of seizure types



Partial (Focal) Seizures

Occur in just one part of the brain.
About 60 percent of people with epilepsy have focal seizures.
These seizures are frequently described by the area of the brain in which they originate:
e.g. someone might be diagnosed with focal frontal lobe seizures.


Classification of Partial Seizures
Simple Partial Seizures: these may have motor features, sensory symptoms etc, but consciousness is not impaired.
Complex Partial Seizures: at some point consciousness is impaired.
Partial Seizures with 2ry generalization

Simple Partial Seizures

The person will remain conscious but experience unusual feelings or sensations that can take many forms.
The person may experience sudden and unexplainable feelings of anger, sadness, or nausea.
He or she also may hear, smell, taste, see, or feel things that are not real.

Motor features

Autonomic
Somatosensory
Visual
Auditory


Complex Partial Seizures(Psychomotor/Temporal Lobe Epilepsy )

The person has a change in or impairment of consciousness.
His or her consciousness may be altered, producing a dreamlike experience.
Typically originate in frontal or temporal lobes.
People having a complex focal seizure may display strange, repetitious behaviors such as blinks, twitches, mouth movements, or even walking in a circle.
These repetitious movements are called automatisms.
Patients may also continue activities they started before the seizure began, such as washing dishes in a repetitive, unproductive fashion.
These seizures usually last just a few seconds.


Impairment of consciousness
Auditory hallucinations
Visual hallucinations
olfactory hallucinations
Psychomotor phenomena


Partial Seizures with Secondary Generalization


Begins focally, with or without focal neurological symptoms

Variable symmetry, intensity, and duration of tonic (stiffening) and clonic (jerking) phases
Typical duration up to 1-2 minutes
Postictal confusion, somnolence, with or without transient focal deficit

Aura

Some people with Partial (focal) seizures, especially complex focal seizures, may experience auras (unusual sensatiaons that warn of an impending seizure).
These auras are actually simple focal seizures in which the person maintains consciousness , tend to be stereotyped, or similar every time.

Primary Generalized Seizures

Generalized seizures are a result of abnormal neuronal activity on both sides of the brain.
These seizures may cause loss of consciousness, falls, or massive muscle spasms.
Excessive electrical activity in both cerebral hemispheres. Affects the whole body.


Generalized Seizures
Absence seizures
Tonic seizures
Clonic seizures
Myoclonic seizures
Atonic seizures
Tonic-clonic

Generalized Tonic-Clonic Seizures

(Grand Mal Epilepsy)
Features a loss of consciousness .
Tonic phase followed by clonic phase.
Cause a mixture of symptoms, including stiffening of the body and repeated jerks of the arms and/or legs as well as loss of consciousness.
Tonic-clonic seizures are sometimes referred to by an older term: grand mal seizures.


Epileptic Cry
Breathing is impaired
Skin turns blue/grey colour
Saliva builds up in the mouth
Lasts 1-3 minutes


The following signs and symptoms occur in some but not all people with grand mal seizures:
Aura: Some people experience a warning feeling (aura) before a grand mal seizure.
Loss of bowel and bladder control: This may happen during or following a seizure.
Unresponsiveness after convulsions: Unconsciousness may persist for a few minutes.
Confusion: A period of disorientation often follows a grand mal seizure.
Fatigue: Sleepiness is common after a grand mal seizure
Severe headache: Headaches are common but not universal after grand mal seizures.

Absence Seizures

(Petit Mal Epilepsy)
Person appears to blank out.
The person may appear to be staring into space and/or have jerking or twitching muscles.
These seizures are sometimes referred to as petit mal seizures, which is an older term.


Sudden loss of awareness

Lasts 1-10 seconds


Resume activity




Tonic Seizure
Cause stiffening of muscles of the body, generally those in the back, legs, and arms.
Clonic Seizure
Cause repeated jerking movements of muscles on both sides of the body.

Myoclonic Seizure

Cause jerks or twitches of the upper body, arms, or legs
Brief shock-like muscle jerks
Generalized or restricted to part of one extremity

Atonic Seizure

Cause a loss of normal muscle tone.
The affected person will fall down or may drop his or her head involuntarily

Status Epilepticus

Juvenile Myoclonic Epilepsy
Juvenile Myoclonic Epilepsy (JME) is a common epileptic syndrome, the etiology of which is genetically determined.
affected patients present with myoclonic jerks, often associated with generalized tonic-clonic seizures - the most common association and absence seizures.
JME is non-progressive, and there are no abnormalities on clinical examination or intellectual deficits.
During myoclonic jerks, consciousness is well preserved.
GTCS are present in 80-97% of patients and appear months or years after onset of myoclonias.
They are often preceded by generalized mild to moderate myoclonic jerks of increasing frequency and intensity, which last a few minutes.


Precipitating factors of JME
Sleep deprivation, reported in 58.3-89.5% of cases.
fatigue (73.7%),
photosensitivity (36.8%),
menses (24.1%),
mental concentration(22.8%),
stress, excitement, or frustration (12.3%),
alcohol ingestion (51.2).

Management of Epileptic Seizures

Questions raised after the first seizure
● Seizure or not?
● Partial or generalized?
● Seizure type?
● Metabolic precipitant?
● Evidence of interictal CNS dysfunction?
● What studies are needed?
● Start AED?

Seizure precipitants

● Metabolic and electrolyte imbalance: low glucose, low Ca, low Na, low Mg
● Stimulants/other proconvulsants intoxication: cocaine, ephedrine
● Sedatives or ETOH withdrawal
● Sleep deprivation, stress
● AED reduction or inadquate dose
● Hormonal variations
● Fever or systemic infections
● Concussion and/or close head injury


Evaluation of a first seizure
● History and physical examination
Often, pt is amnestic for the events surrounding the seizure, and the description must be obtained from friends, relatives
● Blood tests
CBC, electrolytes, glucose, Ca, Mg, Phos, hepatic and renal function
● Blood or urine screen for drugs
● EEG
● CT or MRI of the brain
● LP only if meningitis or encephalitis are suspected (and potential for brain herniation is ruled out)

Lines of Management

Anti-epileptic Drug Therapy
Surgical Treatment

Criteria of an Optimal Medication

A single medication
Effective control of seizures
Does not interfere with normal cognitive or intellectual functions
Effective with the lowest possible dose
With the least systemic side effects


When to initiate Antiepileptic Drug Therapy
● AED therapy should be started in any patient with recurrent seizures of unknown etiology or a known cause that cannot be reversed.
● Patients with a single seizure due to an identified lesion such as a CNC tumor .
● The risk of seizure recurrence in a patient with single an apparently unprovoked or idiopathic seizure is 31 to 71% in the first 12 months.

Risk factors associated with recurrent seizures include the following

Abnormal neurologic examination.
Seizures presenting as status epilepticus.
Postictal Todd’s paralysis.
Strong family history of seizures.
Abnormal EEG.
Patients with one or more of these risk factors should be treated.

Choosing Antiepileptic Drugs
( Seizure type
( Epilepsy syndrome
( Pharmacokinetic profile
( Interactions/other medical condition
( Efficacy
( Expected adverse effects
( Cost


Mode of Action of Anti-epileptics
● Elevation of excitatory impulse threshold
● Prolongation of the refractory period
● Potentiating of inhibitory neurotransmitters (GABA & glycine(
● Inhibition of excitatory neurotransmitters )asparyate & glutamate(

Choosing Antiepileptic Drugs

Partial onset seizures
carbamazepine
oxcarbazepine
Phenytoin
Lamotrigine
Topiramate
Levetiracetam
Valproate

AEDs that have shown efficacy for Absence seizures:

Ethosuximide
Valproate
Lamotrigine
Levetiracetam
Topiramate
Zonisamide


AEDs that have shown efficacy for myoclonic seizures:
Valproate
Clonazapam
Lamotrigine
Levetiracetam
Topiramate
Zonisamide

AEDs that have shown efficacy for Tonic Clonic seizures:

( Valproate
( Lamotrigine
( Topiramate
( Phenytoin
( Felbamate
( Levetiracetam
( Carbamazepine
( Zonisamide
( Oxcarbazepine

● Epileptic patients want to receive treatment based on the best possible recommendations appropriate to the particular type of epilepsy syndrome they have, esp. with the new AEDs
● Aim of pharmacotherapy is to reduce seizure frequency without adverse effects, best is NO SEIZURES, NO SIDE EFFECTS


Monotherapy
Epilepsy Surgery
Focal cortical resection
Corpus Callosotomy
Hemispherectomy
Multiple Subpial Transections
Vagal Nerve Stimulation

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