SEIZURESSEIZURES

SEIZURESSEIZURES

DefDef: : Paroxysmal involuntary disturbance Paroxysmal involuntary disturbance in brain function manifested as impairment in brain function manifested as impairment or loss of consciousness , abnormal motor or loss of consciousness , abnormal motor activity , behavioral abnormalities , activity , behavioral abnormalities , sensory disturbances , or autonomic sensory disturbances , or autonomic dysfunction . dysfunction .

EpilepsyEpilepsy is diagnosed when 2 or is diagnosed when 2 or more unprovoked seizures occur more unprovoked seizures occur at interval greater than 24 hours at interval greater than 24 hours apartapart

Types of epilepsyTypes of epilepsy

There are two basic types of seizures caused by There are two basic types of seizures caused by epilepsy epilepsy ::

1-PARTIAL SEIZURES : begin in a specific 1-PARTIAL SEIZURES : begin in a specific location in the brain. Partial seizures may affect location in the brain. Partial seizures may affect awareness or only one side or part of the body, awareness or only one side or part of the body, but they may also progress to affect the entire but they may also progress to affect the entire bodybody..

2-GENERALIZED SEIZURES: begin over 2-GENERALIZED SEIZURES: begin over the entire surface of the brain and may the entire surface of the brain and may affect the entire body. In people who have affect the entire body. In people who have generalized seizures, it is impossible to generalized seizures, it is impossible to pinpoint a specific location in the brain that pinpoint a specific location in the brain that is the source of the seizure.is the source of the seizure.

The difference is important, because The difference is important, because partial seizures and generalized seizures partial seizures and generalized seizures are often treated differently. The distinction are often treated differently. The distinction is a key factor in guiding treatment.is a key factor in guiding treatment.

International classification of International classification of epileptic seizuresepileptic seizures

PARTIAL SEIZURESPARTIAL SEIZURES::SIMPLE PARTIALSIMPLE PARTIAL MotorMotor SensorySensory AutonomicAutonomic Psychic'Psychic'COMPLEX PARTIALCOMPLEX PARTIALPARTIAL SEIZURES WITH 2ry PARTIAL SEIZURES WITH 2ry GENERALIZATIONGENERALIZATION

GENERALIZED SEIZURES:GENERALIZED SEIZURES:

ABSENCESABSENCES

TypicalTypical

AtypicalAtypical

GENERALIZED TONIC CLONICGENERALIZED TONIC CLONIC

TONICTONIC

CLONICCLONIC

MYOCLONICMYOCLONIC

ATONICATONIC

INFANTILE SPASMSINFANTILE SPASMS

UNCLASSIFIED SEIZURESUNCLASSIFIED SEIZURES

CriterionCriterion SPSSPS CPSCPS

ConsciousnessConsciousnessRetained Retained impairedimpaired

AuraAuraMay be presentMay be presentAlways indicatesAlways indicatesA focal onset A focal onset

(1/3) (1/3)

AutomatismAutomatismNo No 50-75%50-75%

Duration Duration 10-20 sec 10-20 sec 1-2 min1-2 min

PATHOPHYSIOLOGYPATHOPHYSIOLOGY

Two sets of changes can determine the Two sets of changes can determine the epileptogenic properties of neuronal epileptogenic properties of neuronal tissues. Abnormal neuronal excitability is tissues. Abnormal neuronal excitability is thought to occur as a result of disruption of thought to occur as a result of disruption of the depolarization and repolarization the depolarization and repolarization mechanisms of the cell (this is termed the mechanisms of the cell (this is termed the "excitability of neuronal tissue"). "excitability of neuronal tissue").

Aberrant neuronal networks that develop Aberrant neuronal networks that develop abnormal synchronization of a group of abnormal synchronization of a group of neurons can result in the development and neurons can result in the development and propagation of an epileptic seizure (this is propagation of an epileptic seizure (this is termed the "synchronization of neuronal termed the "synchronization of neuronal tissue").tissue").

A hyperexcitability of neurons that results A hyperexcitability of neurons that results in random firing of cells, by itself, may not in random firing of cells, by itself, may not lead to propagation of an epileptic seizure. lead to propagation of an epileptic seizure. Indeed, both normal and abnormal Indeed, both normal and abnormal patterns of behavior require a certain patterns of behavior require a certain degree of synchronization of firing in a degree of synchronization of firing in a population of neurons. population of neurons.

Epileptic seizures originate in a setting of Epileptic seizures originate in a setting of both altered excitability and altered both altered excitability and altered synchronization of neurons. synchronization of neurons.

The excitability of individual neurons is The excitability of individual neurons is affected by:affected by:cell membrane properties and the microencell membrane properties and the microenvironment of the neuronvironment of the neuron intracellular processesintracellular processes structural features of neuronal elementsstructural features of neuronal elements interneuronalinterneuronal connections connections

Benign Rolandic EpilepsyBenign Rolandic Epilepsy

Benign Rolandic epilepsy (also known as Benign Rolandic epilepsy (also known as benign partial epilepsy of childhood) benign partial epilepsy of childhood) accounts for more than one-third of all accounts for more than one-third of all cases of epilepsy that begin in middle cases of epilepsy that begin in middle childhood, accounting for 16 percent of childhood, accounting for 16 percent of those beginning before age 15. There is a those beginning before age 15. There is a family history in 18 percent of cases and family history in 18 percent of cases and the condition is probably genetically the condition is probably genetically determined.determined.

Rasmussen's SyndromeRasmussen's Syndrome

Rasmussen's syndrome, also known as Rasmussen's syndrome, also known as Rasmussen's encephalitis, begins in Rasmussen's encephalitis, begins in childhood and produces a slow childhood and produces a slow deterioration of one whole side deterioration of one whole side (hemisphere) of the brain with loss of (hemisphere) of the brain with loss of function on the opposite side of the function on the opposite side of the body. An autoimmune response to a body. An autoimmune response to a viral infection has been suggested as a viral infection has been suggested as a possible cause. possible cause.

Various types of treatment have been Various types of treatment have been tried, including surgical removal of the tried, including surgical removal of the affected side of the brain. In children, affected side of the brain. In children, the remaining hemisphere may the remaining hemisphere may compensate for functions lost, but compensate for functions lost, but weakness on the affected side will weakness on the affected side will remain.remain.

Childhood Absence EpilepsyChildhood Absence Epilepsy

Childhood AbsenceChildhood Absence 40% outgrow seizures 40% outgrow seizures I.Q. scores 10% above normal I.Q. scores 10% above normal Probably inherited Probably inherited Generalized tonic-clonic in 50%Generalized tonic-clonic in 50%

Children with this syndrome are otherwise Children with this syndrome are otherwise normal; 40 percent outgrow the seizures, normal; 40 percent outgrow the seizures, and as a group their I.Q. scores are 10 and as a group their I.Q. scores are 10 points above average. The syndrome is points above average. The syndrome is inherited (probably autosomal dominant inherited (probably autosomal dominant trait with age-dependent expression).trait with age-dependent expression).

Childhood absence epilepsy (also called Childhood absence epilepsy (also called petit mal epilepsy, pyknolepsy) accounts petit mal epilepsy, pyknolepsy) accounts for 2 to 4 percent of all cases of epilepsy in for 2 to 4 percent of all cases of epilepsy in children. Seizures are non-convulsive children. Seizures are non-convulsive staring spells associated with a distinct 3 staring spells associated with a distinct 3 per second spike and wave EEG pattern. per second spike and wave EEG pattern. The seizures tend to occur in clusters The seizures tend to occur in clusters (hence pyknolepsy -- derived from the (hence pyknolepsy -- derived from the Greek word for "cluster").Greek word for "cluster").

Despite its overall benign nature, Despite its overall benign nature, approximately half of the children with approximately half of the children with absence epilepsy can expect to have a absence epilepsy can expect to have a generalized tonic clonic seizure. The risk generalized tonic clonic seizure. The risk is higher if the EEG background readings is higher if the EEG background readings are abnormal, or if the child has are abnormal, or if the child has neurological deficits. The risk is reduced if neurological deficits. The risk is reduced if seizures are quickly controlled with seizures are quickly controlled with medication.medication.

Remission of childhood absence epilepsy Remission of childhood absence epilepsy is most likely when the child is young at is most likely when the child is young at onset, the seizures are easily controlled onset, the seizures are easily controlled with medication and there are no other with medication and there are no other neurological problemsneurological problems. .

MYOCLONIC EPILEPSIES MYOCLONIC EPILEPSIES OF CHILDHOODOF CHILDHOOD

Charcterized by repetitive seizures Charcterized by repetitive seizures consisting of brief, often symmetric muscle consisting of brief, often symmetric muscle

contractions with losas of body tone contractions with losas of body tone and falling or slumping forward. and falling or slumping forward.

Myoclonic epilepsies include a Myoclonic epilepsies include a heterogeneous group of conditions heterogeneous group of conditions with multiple causes and variable with multiple causes and variable outcomes: outcomes:

1.1. Benign Myoclonus of Infancy. Benign Myoclonus of Infancy.

2.2. Typical Myoclonic Epilepsy of Early Typical Myoclonic Epilepsy of Early Childhood. Childhood.

3.3. Complex Myoclonic Epilepsies. Complex Myoclonic Epilepsies.

4.4. Juvenile Myoclonic Epilepsy. Juvenile Myoclonic Epilepsy.

5.5. Progressive Myoclonic Epilepsies. Progressive Myoclonic Epilepsies.

Benign Myoclonus of Benign Myoclonus of InfancyInfancy: :

-     Benign myoclonus begins during -     Benign myoclonus begins during infancy and consists of clusters of infancy and consists of clusters of myoclonic movements confined to the myoclonic movements confined to the neck, trunk, and extremities. neck, trunk, and extremities.

-     The myoclonic activity may be -     The myoclonic activity may be confused with infantile spasms; however, confused with infantile spasms; however, the EEG is normal in patients with benign the EEG is normal in patients with benign myoclonus. myoclonus.

The prognosis is good, with normal The prognosis is good, with normal development and the cessation of development and the cessation of myoclonus by 2 yr of age. myoclonus by 2 yr of age.

-     An anticonvulsant is not indicated. -     An anticonvulsant is not indicated.

-     A familial autosomal dominant form is -     A familial autosomal dominant form is thought to be linked to a locus on thought to be linked to a locus on chromosome 20chromosome 20

Typical Myoclonic Epilepsy of Typical Myoclonic Epilepsy of Early ChildhoodEarly Childhood

- Pure form of myoclonic epilepsy in which - Pure form of myoclonic epilepsy in which genetic factors are important : at least genetic factors are important : at least 1/3 1/3 + family Hx of epilepsy + family Hx of epilepsy - Mean age of onset : 2.5 yr - Mean age of onset : 2.5 yr Range : 6 mo-4 yrRange : 6 mo-4 yr

Children who develop typical myoclonic Children who develop typical myoclonic epilepsy are near normal prior to the epilepsy are near normal prior to the onset of seizures with no previous onset of seizures with no previous evidence of brain damage and intact evidence of brain damage and intact developmental milestones.developmental milestones.

The frequency of myoclonic seizures varies; The frequency of myoclonic seizures varies; they may occur several times daily or children they may occur several times daily or children may be seizure free for weeks. may be seizure free for weeks. - Present as : head nodding, more violent jerks - Present as : head nodding, more violent jerks of shoulder, flexion of the arms, trunk or legs. of shoulder, flexion of the arms, trunk or legs.

- A few patients have febrile convulsions - A few patients have febrile convulsions or generalized tonic-clonic afebrile or generalized tonic-clonic afebrile seizures that precede the onset of seizures that precede the onset of myoclonic epilepsy. myoclonic epilepsy.

Approximately one half of the patients Approximately one half of the patients occasionally have tonic-clonic seizures in occasionally have tonic-clonic seizures in addition to the myoclonic epilepsy. The addition to the myoclonic epilepsy. The EEG shows fast spike wave complexes of EEG shows fast spike wave complexes of equal to or greater than 2.5 Hz and a equal to or greater than 2.5 Hz and a normal background rhythm in most cases. normal background rhythm in most cases.

  The long-term outcome is relatively favorable. The long-term outcome is relatively favorable. - Mental retardation develops in the minority - Mental retardation develops in the minority - More than 50% are seizure free several years later. - More than 50% are seizure free several years later. -  However, learning and language problems and -  However, learning and language problems and emotional and behavioral disorders occur in a significant emotional and behavioral disorders occur in a significant number of these children and require prolonged follow-number of these children and require prolonged follow-up by a multidisciplinary team. up by a multidisciplinary team.     -    Attacks usually respond well to valproic acid -    Attacks usually respond well to valproic acid

Juvenile Myoclonic Epilepsy : Juvenile Myoclonic Epilepsy : Janz syndrome Janz syndrome

( ( Impulsive petit malImpulsive petit mal - Primary generalized epilepsy - Primary generalized epilepsy

-     Juvenile myoclonic epilepsy usually -     Juvenile myoclonic epilepsy usually begins between the ages of 12 and 16 yr ( begins between the ages of 12 and 16 yr ( early teens ) early teens )

-     accounts for approximately 5 % of the -     accounts for approximately 5 % of the epilepsies. epilepsies.

Genetic factors are important. Family Genetic factors are important. Family history of epilepsy in up to 25 % history of epilepsy in up to 25 %

-     A gene locus has been identified on -     A gene locus has been identified on chromosome 6p. chromosome 6p.

-  The neurologic examination is normal -  The neurologic examination is normal

the distinctive features of JME : the distinctive features of JME :

-  Morning myoclonic jerks -  Morning myoclonic jerks

-  Generalized tonic-clonic convulsions just -  Generalized tonic-clonic convulsions just after awaking after awaking

-  Normal intelligence -  Normal intelligence

-  Positive family history of similar seizures -  Positive family history of similar seizures

-  Myoclonic jerks occurs shortly after the -  Myoclonic jerks occurs shortly after the patient awakes patient awakes

Lennox-Gastaut SyndromeLennox-Gastaut Syndrome

Atypical absense Atypical absense

Tonic seizures Tonic seizures

Drop attacks Drop attacks

Mental retardation Mental retardation

Slow spike wave Slow spike wave

Onset before age 5Onset before age 5

))West SyndromeWest Syndrome((

West syndrome is composed of the triad of West syndrome is composed of the triad of infantile spasms, an interictal EEG pattern infantile spasms, an interictal EEG pattern termed hypsarrhythmia, and mental termed hypsarrhythmia, and mental retardation, although the diagnosis can be retardation, although the diagnosis can be made even if one of the 3 elements is made even if one of the 3 elements is missing (according to the international missing (according to the international classification). This severe epilepsy classification). This severe epilepsy syndrome is an age-dependent expression syndrome is an age-dependent expression of a damaged brainof a damaged brain

Spasms can be flexor, extensor, or a Spasms can be flexor, extensor, or a mixture of flexion and extensionmixture of flexion and extension. . An An arrest or regression in psychomotor arrest or regression in psychomotor development accompanies the onset development accompanies the onset of spasms in 70-95% of patients of spasms in 70-95% of patients

Infantile spasms (West syndrome) can Infantile spasms (West syndrome) can be classified according to its be classified according to its suspected etiology as symptomatic, suspected etiology as symptomatic, cryptogenic, or idiopathic. Virtually cryptogenic, or idiopathic. Virtually any disorder that can produce brain any disorder that can produce brain damage can be associated with damage can be associated with infantile spasmsinfantile spasms

Landau-Kleffner SyndromeLandau-Kleffner Syndrome

Begins between 3 to 7 years old Begins between 3 to 7 years old

Progressive loss of speech Progressive loss of speech

Seizures during sleep Seizures during sleep

Loss of IQLoss of IQ

Language for many of these children will Language for many of these children will improve slowly over time, but may not improve slowly over time, but may not return to a normal level for age. EEGs may return to a normal level for age. EEGs may continue to be abnormal, even when the continue to be abnormal, even when the speech has improvedspeech has improved

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