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  1. 1. SEIZURES
  2. 2. SEIZURES <ul><li>Def : Paroxysmal involuntary disturbance in brain function manifested as impairment or loss of consciousness , abnormal motor activity , behavioral abnormalities , sensory disturbances , or autonomic dysfunction . </li></ul>
  3. 3. <ul><li>Epilepsy is diagnosed when 2 or more unprovoked seizures occur at interval greater than 24 hours apart </li></ul>
  4. 4. Types of epilepsy <ul><li>There are two basic types of seizures caused by epilepsy : 1-PARTIAL SEIZURES : begin in a specific location in the brain. Partial seizures may affect awareness or only one side or part of the body, but they may also progress to affect the entire body . </li></ul>
  5. 5. <ul><li>2-GENERALIZED SEIZURES: begin over the entire surface of the brain and may affect the entire body. In people who have generalized seizures, it is impossible to pinpoint a specific location in the brain that is the source of the seizure. </li></ul>
  6. 6. <ul><li>The difference is important, because partial seizures and generalized seizures are often treated differently. The distinction is a key factor in guiding treatment. </li></ul>
  7. 7. International classification of epileptic seizures <ul><li>PARTIAL SEIZURES : </li></ul><ul><li>SIMPLE PARTIAL </li></ul><ul><li>Motor </li></ul><ul><li>Sensory </li></ul><ul><li>Autonomic </li></ul><ul><li>Psychic' </li></ul><ul><li>COMPLEX PARTIAL </li></ul><ul><li>PARTIAL SEIZURES WITH 2ry GENERALIZATION </li></ul>
  8. 8. <ul><li>GENERALIZED SEIZURES: </li></ul><ul><li>ABSENCES </li></ul><ul><li>Typical </li></ul><ul><li>Atypical </li></ul><ul><li>GENERALIZED TONIC CLONIC </li></ul><ul><li>TONIC </li></ul><ul><li>CLONIC </li></ul><ul><li>MYOCLONIC </li></ul><ul><li>ATONIC </li></ul><ul><li>INFANTILE SPASMS </li></ul><ul><li>UNCLASSIFIED SEIZURES </li></ul>
  9. 9. 1-2 min 10-20 sec Duration 50-75% No Automatism Always indicates A focal onset (1/3) May be present Aura impaired Retained Consciousness CPS SPS Criterion
  10. 10. PATHOPHYSIOLOGY <ul><li>Two sets of changes can determine the epileptogenic properties of neuronal tissues. Abnormal neuronal excitability is thought to occur as a result of disruption of the depolarization and repolarization mechanisms of the cell (this is termed the &quot;excitability of neuronal tissue&quot;). </li></ul>
  11. 11. <ul><li>Aberrant neuronal networks that develop abnormal synchronization of a group of neurons can result in the development and propagation of an epileptic seizure (this is termed the &quot;synchronization of neuronal tissue&quot;). </li></ul>
  12. 12. <ul><li>A hyperexcitability of neurons that results in random firing of cells, by itself, may not lead to propagation of an epileptic seizure. Indeed, both normal and abnormal patterns of behavior require a certain degree of synchronization of firing in a population of neurons. </li></ul>
  13. 13. <ul><li>Epileptic seizures originate in a setting of both altered excitability and altered synchronization of neurons. </li></ul>
  14. 14. <ul><li>The excitability of individual neurons is affected by: </li></ul><ul><li>cell membrane properties and the microenvironment of the neuron </li></ul><ul><li>intracellular processes </li></ul><ul><li>structural features of neuronal elements </li></ul><ul><li>interneuronal connections </li></ul>
  15. 15. Benign Rolandic Epilepsy <ul><li>Benign Rolandic epilepsy (also known as benign partial epilepsy of childhood) accounts for more than one-third of all cases of epilepsy that begin in middle childhood, accounting for 16 percent of those beginning before age 15. There is a family history in 18 percent of cases and the condition is probably genetically determined. </li></ul>
  16. 16. Rasmussen's Syndrome <ul><li>Rasmussen's syndrome, also known as Rasmussen's encephalitis, begins in childhood and produces a slow deterioration of one whole side (hemisphere) of the brain with loss of function on the opposite side of the body. An autoimmune response to a viral infection has been suggested as a possible cause. </li></ul>
  17. 17. <ul><li>Various types of treatment have been tried, including surgical removal of the affected side of the brain. In children, the remaining hemisphere may compensate for functions lost, but weakness on the affected side will remain. </li></ul>
  18. 18. Childhood Absence Epilepsy <ul><li>Childhood Absence </li></ul><ul><li>40% outgrow seizures </li></ul><ul><li>I.Q. scores 10% above normal </li></ul><ul><li>Probably inherited </li></ul><ul><li>Generalized tonic-clonic in 50% </li></ul>
  19. 19. <ul><li>Children with this syndrome are otherwise normal; 40 percent outgrow the seizures, and as a group their I.Q. scores are 10 points above average. The syndrome is inherited (probably autosomal dominant trait with age-dependent expression). </li></ul>
  20. 20. <ul><li>Childhood absence epilepsy (also called petit mal epilepsy, pyknolepsy) accounts for 2 to 4 percent of all cases of epilepsy in children. Seizures are non-convulsive staring spells associated with a distinct 3 per second spike and wave EEG pattern. The seizures tend to occur in clusters (hence pyknolepsy -- derived from the Greek word for &quot;cluster&quot;). </li></ul>
  21. 21. <ul><li>Despite its overall benign nature, approximately half of the children with absence epilepsy can expect to have a generalized tonic clonic seizure. The risk is higher if the EEG background readings are abnormal, or if the child has neurological deficits. The risk is reduced if seizures are quickly controlled with medication. </li></ul>
  22. 22. <ul><li>Remission of childhood absence epilepsy is most likely when the child is young at onset, the seizures are easily controlled with medication and there are no other neurological problems . </li></ul>
  23. 23. MYOCLONIC EPILEPSIES OF CHILDHOOD <ul><li>Charcterized by repetitive seizures consisting of brief, often symmetric muscle </li></ul><ul><li>contractions with losas of body tone and falling or slumping forward. </li></ul>
  24. 24. <ul><li>Myoclonic epilepsies include a heterogeneous group of conditions with multiple causes and variable outcomes: </li></ul><ul><li>Benign Myoclonus of Infancy. </li></ul><ul><li>Typical Myoclonic Epilepsy of Early Childhood. </li></ul><ul><li>Complex Myoclonic Epilepsies. </li></ul><ul><li>Juvenile Myoclonic Epilepsy. </li></ul><ul><li>Progressive Myoclonic Epilepsies. </li></ul>
  25. 25. Benign Myoclonus of Infancy : <ul><li>-     Benign myoclonus begins during infancy and consists of clusters of myoclonic movements confined to the neck, trunk, and extremities. </li></ul><ul><li>-     The myoclonic activity may be confused with infantile spasms; however, the EEG is normal in patients with benign myoclonus. </li></ul>
  26. 26. <ul><li>The prognosis is good, with normal development and the cessation of myoclonus by 2 yr of age. </li></ul><ul><li>-     An anticonvulsant is not indicated. </li></ul><ul><li>-     A familial autosomal dominant form is thought to be linked to a locus on chromosome 20 </li></ul>
  27. 27. Typical Myoclonic Epilepsy of Early Childhood <ul><li>- Pure form of myoclonic epilepsy in which genetic factors are important : at least 1/3  + family Hx of epilepsy </li></ul><ul><li>- Mean age of onset : 2.5 yr Range : 6 mo-4 yr </li></ul>
  28. 28. <ul><li>Children who develop typical myoclonic epilepsy are near normal prior to the onset of seizures with no previous evidence of brain damage and intact developmental milestones. </li></ul>
  29. 29. <ul><li>The frequency of myoclonic seizures varies; they may occur several times daily or children may be seizure free for weeks. </li></ul><ul><li>- Present as : head nodding, more violent jerks of shoulder, flexion of the arms, trunk or legs. </li></ul>
  30. 30. <ul><li>- A few patients have febrile convulsions or generalized tonic-clonic afebrile seizures that precede the onset of myoclonic epilepsy. </li></ul>
  31. 31. <ul><li>Approximately one half of the patients occasionally have tonic-clonic seizures in addition to the myoclonic epilepsy. The EEG shows fast spike wave complexes of equal to or greater than 2.5 Hz and a normal background rhythm in most cases. </li></ul>
  32. 32. <ul><li>  The long-term outcome is relatively favorable. </li></ul><ul><li>- Mental retardation develops in the minority </li></ul><ul><li>- More than 50% are seizure free several years later. </li></ul><ul><li>-  However, learning and language problems and emotional and behavioral disorders occur in a significant number of these children and require prolonged follow-up by a multidisciplinary team. </li></ul><ul><li>  </li></ul><ul><li>-    Attacks usually respond well to valproic acid </li></ul>
  33. 33. Juvenile Myoclonic Epilepsy : Janz syndrome ( Impulsive petit mal <ul><li>- Primary generalized epilepsy </li></ul><ul><li>-     Juvenile myoclonic epilepsy usually begins between the ages of 12 and 16 yr ( early teens ) </li></ul><ul><li>-     accounts for approximately 5 % of the epilepsies. </li></ul>
  34. 34. <ul><li>Genetic factors are important. Family history of epilepsy in up to 25 % </li></ul><ul><li>-     A gene locus has been identified on chromosome 6p. </li></ul><ul><li>-  The neurologic examination is normal </li></ul>
  35. 35. <ul><li>the distinctive features of JME : </li></ul><ul><li>-  Morning myoclonic jerks </li></ul><ul><li>-  Generalized tonic-clonic convulsions just after awaking </li></ul><ul><li>-  Normal intelligence </li></ul><ul><li>-  Positive family history of similar seizures </li></ul><ul><li>-  Myoclonic jerks occurs shortly after the patient awakes </li></ul>
  36. 36. Lennox-Gastaut Syndrome <ul><li>Atypical absense </li></ul><ul><li>Tonic seizures </li></ul><ul><li>Drop attacks </li></ul><ul><li>Mental retardation </li></ul><ul><li>Slow spike wave </li></ul><ul><li>Onset before age 5 </li></ul>
  37. 37. (West Syndrome) <ul><li>West syndrome is composed of the triad of infantile spasms, an interictal EEG pattern termed hypsarrhythmia, and mental retardation, although the diagnosis can be made even if one of the 3 elements is missing (according to the international classification). This severe epilepsy syndrome is an age-dependent expression of a damaged brain </li></ul>
  38. 38. <ul><li>Spasms can be flexor, extensor, or a mixture of flexion and extension . An arrest or regression in psychomotor development accompanies the onset of spasms in 70-95% of patients </li></ul>
  39. 39. <ul><li>Infantile spasms (West syndrome) can be classified according to its suspected etiology as symptomatic, cryptogenic, or idiopathic. Virtually any disorder that can produce brain damage can be associated with infantile spasms </li></ul>
  40. 40. Landau-Kleffner Syndrome <ul><li>Begins between 3 to 7 years old </li></ul><ul><li>Progressive loss of speech </li></ul><ul><li>Seizures during sleep </li></ul><ul><li>Loss of IQ </li></ul>
  41. 41. <ul><li>Language for many of these children will improve slowly over time, but may not return to a normal level for age. EEGs may continue to be abnormal, even when the speech has improved </li></ul>
  42. 42. THANK YOU