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Epilepsy cause and classification. By: Dr. Zinab Mofadl. A seizure is a symptom of many different disorders that can affect the brain, it is an event not a disease itself. In centuries past, the word "seizure " referred to people being taken over by supernatural forces.
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Epilepsy cause and classification By: Dr. ZinabMofadl
A seizure is a symptom of many different disorders that can affect the brain, it is an event not a disease itself. • In centuries past, the word "seizure" referred to people being taken over by supernaturalforces.
What is epilepsy: Seizure: is a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Epilepsy: is a disorder of the brain characterized by an enduring predisposition to generate epileptic seizures, and by the neurobiological, cognitive, psychological, and social consequences of this condition.
Seizures result from an electrochemical disorder in the brain. • Each brain cell either excites or inhibits other brain cells with its discharges. When the balance of excitation and inhibition in a region of brain is moved too far in the direction of excitation, then a seizure can result.
Cause of Seizures: • Non-epileptic • epileptic
Non-epileptic • Febril convulsion • Infection :meningitis ,encephalitis ,brain abscess • Irritation: brain odema • Tumer of brain • Toxic :tetanus,or drugs as aminophylline • Hemorrhage :trauma ,hemorrhagic blood disease • Hypoxia: hypoxic ischemic encephalopathy • Hypertensive, uraemic, hepatic enchephalopathy Metabolic: hypo(glycamia,calcaemia,magnesaemia) hypo or hypernatremia pyridoxine(b6) deficincy
Congenital Malformation • degenerative brain disorder • Tumours • inborn error of metabolism • stroke • Post traumatic • Post haemorrhage • Post infection • Post toxic • Post anoxic
Classification: Secondary generalized simple complex absence Myoclonic Tonic-clonic Tonic Atonic
Partial epilepsy: • It is only involved one part of body. • Partial seizures constitute 40% to 60% of the classifiable epilepsies of childhood. • It is caused by focal brain lesions (tumors, infarct, dysgenesis), but most partial seizures in children are due to genetic influences (rolandic seizures).
“Aura”: • Is present in approximately one third of children with SPS and CPS. • always indicates a focal onset of the seizure • Children <7 yr old are less likely than older children to report auras
Automatisms: • are a common feature of CPS in infants and children • occurring in ≈50–75% of cases • the older the child, the greater is the frequency of automatisms. • Automatisms develop after the loss of consciousness and may persist into the postictal phase.
In infants: is characterized by alimentary automatisms including : lip smacking chewing, swallowing excessive salivation.
In older children :consists of semi-purposeful, incoordinated, and unplanned gestural automatisms, including:picking and pulling at clothing or bed sheets rubbing or caressing objects walking or running in a nondirective repetitive, and often fearful fashion.
Secondary Generalized Seizures: 1. Simple partial seizures evolving to generalized seizures 2. Complex partial seizures evolving to generalized seizures
GenerlizedEpilepsy: • It Involves both hemispheres of the brain. • Always involves loss of consciousness.
Absence (petit mal): • Brief stare with unresponsiveness(<30 sec). • May have associated eye flutter or simple automatisms. • Sudden onset with arrest of activity • No aura or postictal confusion. • F>M , uncommon before 5 yrs age. 1-Simple (typical) absence Seizure
Hyperventilation for 3-4min routinely produces an absence seizure. • Generalized 3 per second spike and wave. • 80% will experience resolution with age. • 20% will have convulsive seizures
2-Complex (atypical) absence seizure • Associated with myoclonic movement of the face, fingers, or extremities. • Loss of body tone. • precipitated by drowsiness • Produce atypical EEG spike and wave discharges at 2-2.5lsec.
3-Juvenile absence seizure • It is similar to typical absences but occur at a later age and are accompanied by 4-6 Hz spike–and–slow wave and polyspike–and–slow wave discharges. These are usually associated with juvenile myoclonic epilepsy
Generalized tonic clonic seizure • Common and may follow a partial seizure with a focal onset. • Associated with an aura(indicate a site of pathology). • Sudden loss of convulsion ,rolling of eyes , tonic ,then rhythmic clonic convulsion . • Associated with sphincter incontinences. • Posticteal sleep may continues for 30 min to several hrs
Myoclonic • Sudden single jerks of group of muscle. • Single or in clusters • No alteration in consciousness • Associated with loss of body tone and falling or slumping forward. • May progress to clonic-tonic seizure • Generalized multispike wave. • Five distinct subgroupings can be identified.
Atonic • are epileptic drop attacks • No warning, abrupt onset. • Injuries common. • Very difficult to treat. • May respond well to VNS • Corpus callosotomy may prevent falls.
Benign Myoclonus of Infancy: • Begins during infancy . • Myoclonic movements confined to the neck, trunk, and extremities. • EEG is normal. • Prognosis is good . • Normal development and the cessation of myoclonus by 2yr of age. • An anticonvulsant is not indicated.
Juvenile Myoclonic Epilepsy(JME) (Janz syndrome) • Begins at 12-16 yrs of age. • ~5% of epilepsy. • Autosomal dominant inheritance. • At beginning early morning myoclonic jerks occur then abate later in morning. • A few yrs later gen. tonic-clonic seizure with myoclonus.
EEG show 4-6 /sec irreguler spikes. • Neurological exam. normal. • Dramatically response to valporate which required lifelong.
Typical Myoclonic Epilepsy of Early Childhood • The mean age of onset is ~2yr (6mo to 4yr). • Near normal before the onset of seizure. • May occur several times daily, or children may be seizure-free for weeks. • Approximately half of patients occasionally have tonic-clonic seizures . • The EEG shows fast spike wave complexes of >2.5H2 and a normal background rhythm in most cases.
One third of the children have a positive family history of epilepsy(a genetic etiology) • The long-term outcome is relatively favorable. • Mental retardation develops in the minority. • >50%are seizure-free several years later • Learning and language problems and emotional and behavioral disorders.
Complex Myoclonic Epilepsies • A heterogeneous group of disorders with a uniformly poor prognosis. • Focal or generalized tonic-clonic seizures beginning in the 1st yr of life. • Frequently develops into status epilepticus. • One third have evidence of delayed developmental milestones.
A history of hypoxic-ischemic encephalopathy in the perinatal period. • A family history of epilepsy is much less prominent. • Lennox-Gastaut syndrome:(triad of intractable seizures of various types, a slow spike wave EEG during the awake state, and mental retardation). • Slow spike waves and are refractory to anticonvulsants.
Frequency of mental retardation and behavioral problems is ~75% of all patients. • Treatment with valproic acid or benzodiazepines may decrease • The ketogenic diet should be considered for patients have refractory seizures.
Progressive Myoclonic Epilepsies • Heterogeneous group of rare genetic disorders uniformly has a grave prognosis. • These include : Lafora disease, myoclonic epilepsy with ragged-red fibers( MERRF) Sialidosis type 1,ceroid lipofuscinosis ,Juvenile neuropathic, Gaucher disease and luvenileneuroaxonal dystrophy.