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Epilepsy Epilepsy 1

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Epilepsy Epilepsy

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ChapterChapter :9 :9

EpilepsyEpilepsyPresented by: Prof.Mirza Anwar BaigPresented by: Prof.Mirza Anwar Baig

Anjuman-I-Islam's Kalsekar Technical CampusAnjuman-I-Islam's Kalsekar Technical CampusSchool of Pharmacy,New Pavel,Navi School of Pharmacy,New Pavel,Navi

Mumbai,MaharashtraMumbai,Maharashtra

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Seizures Seizures

A seizure is as a sudden, disorderly A seizure is as a sudden, disorderly discharge of cerebral neurons. discharge of cerebral neurons.

Seizures involve a Seizures involve a transient transient alteration in brain alteration in brain function (motor, function (motor, sensory, sensory, autonomic, or autonomic, or psychic clinical psychic clinical manifestations)manifestations) 33

DefinitionDefinitionll A A chronic neurologic disorderchronic neurologic disorder manifesting manifesting

by by repeated epileptic seizures repeated epileptic seizures (attacks or (attacks or fits) which result from fits) which result from uncontrolled uncontrolled discharges of neurons discharges of neurons within the central within the central nervous systemnervous system

ll The clinical manifestations The clinical manifestations rangerange fromfrom a a major motor convulsion to a brief period of major motor convulsion to a brief period of lack of awareness. The uncontrollable nature lack of awareness. The uncontrollable nature of the attacks is characteristic of epilepsy.of the attacks is characteristic of epilepsy.

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Epidemiology and Epidemiology and coursecoursell 5% of the population suffer a single sz at 5% of the population suffer a single sz at

some timesome timell 0.5-1% of the population have recurrent sz 0.5-1% of the population have recurrent sz

= EPILEPSY= EPILEPSYll 70% = well controlled with drugs (prolonged 70% = well controlled with drugs (prolonged

remissions)remissions)ll 30% epilepsy at least partially resistant to 30% epilepsy at least partially resistant to

drug treatmentsdrug treatments

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Types of Seizures Types of Seizures ûû Seizures can be classified as either partial or Seizures can be classified as either partial or

generalizedgeneralizedûû The type of seizure as well as the signs and The type of seizure as well as the signs and

symptoms that accompany the seizure depend symptoms that accompany the seizure depend on the part of the brain in which the seizures on the part of the brain in which the seizures occuroccur

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Types of Seizures - Types of Seizures - PartialPartial

ûû Partial Seizures are seizures that begin locally Partial Seizures are seizures that begin locally (in one part of the brain)(in one part of the brain)

i.i. Simple Partial seizureSimple Partial seizure (consciousness not (consciousness not impaired)impaired)

ii.ii. Complex partial seizureComplex partial seizure (consciousness (consciousness impaired)impaired)

iii.iii. Secondary generalized seizureSecondary generalized seizure (begins (begins as partial and transitions into a as partial and transitions into a generalized seizure)generalized seizure)

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Types of Seizures - GeneralizedTypes of Seizures - Generalizedûû Generalized seizures are bilaterally Generalized seizures are bilaterally

symmetric; there is no local onset and symmetric; there is no local onset and although they involve the entire brain, although they involve the entire brain, physical control is rarely lost. physical control is rarely lost.

ûû Types of GS include:Types of GS include:i.i. Absence seizures (Absence seizures (petit mal)petit mal)-- staring, staring,

slight body movement and short periods slight body movement and short periods of unawareness of unawareness

ii.ii. Myoclonic seizures-Myoclonic seizures- sudden jerks of arms sudden jerks of arms and legsand legs

iii.iii. Atonic seizures (Atonic seizures (drop attacks)-drop attacks)- suddenly suddenly collapse or fall downcollapse or fall down

iv.iv. Tonic-clonic seizures (Tonic-clonic seizures (grand mal)grand mal)-- most most severe type of seizure; characterized by severe type of seizure; characterized by loss of consciousness, body stiffening, loss of consciousness, body stiffening, shaking and sometimes tongue bitingshaking and sometimes tongue biting

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Partial and Generalized Partial and Generalized

Partial Seizure with Secondary Generalization

Primary Generalized Seizure

Partial Seizure

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Etiology - Etiology - EpilepsyEpilepsy

û Metabolic defectsû Congenital

malformation û Genetic

predisposition û Perinatal injury û Postnatal trauma û Myoclonic syndromes û Infectionû Brain tumor û Vascular disease û Fever û Drug and/or alcohol

abuse 1010

Pathogenesis Pathogenesis A seizure occurs when a A seizure occurs when a burst burst of electrical impulses in the of electrical impulses in the brain escape their normal brain escape their normal limits (past threshold).limits (past threshold).

They spread to neighboring They spread to neighboring areas and create an areas and create an uncontrolled storm of cortical uncontrolled storm of cortical nerve cell electrical activity.nerve cell electrical activity.

The electrical impulses can be The electrical impulses can be transmitted to the muscles, transmitted to the muscles, causing twitches or causing twitches or convulsions.convulsions.

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PathogenesisPathogenesis

§§ The 19th century neurologist Hughlings The 19th century neurologist Hughlings Jackson suggested Jackson suggested ““aa sudden sudden excessiveexcessive disorderly disorderly discharge of cerebral discharge of cerebral neuronsneurons““ as the causation of epileptic as the causation of epileptic seizures.seizures.

§§ Recent studies in animal models suggest a Recent studies in animal models suggest a central role for the excitatory neurotransmiter central role for the excitatory neurotransmiter glutamateglutamate and inhibitory gamma amino and inhibitory gamma amino butyric acid (butyric acid (GABAGABA) (decreased)) (decreased)

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B-Slide B-Slide 1313

Normal CNS FunctionNormal CNS Function

ExcitationInhibition

glutamate,aspartate GABA

B-Slide B-Slide 1414

Hyperexcitability reflects both Hyperexcitability reflects both increased excitation and increased excitation and decreased inhibitiondecreased inhibition

Excitation

Inhibition

GABA

glutamate,aspartate

Diagnosis Diagnosis

ûû EEGsEEGs can be used to confirm diagnosis and can be used to confirm diagnosis and determine type of seizuredetermine type of seizure

ûû An An MRIMRI may be ordered if the initial may be ordered if the initial medications pt. is on fail to control seizures or medications pt. is on fail to control seizures or a CT scan if pt. is an older adulta CT scan if pt. is an older adult

ûû Plasma levels of electrolytesPlasma levels of electrolytes, glucose and , glucose and calcium levels, renal function tests, liver calcium levels, renal function tests, liver function tests and even drug screening may be function tests and even drug screening may be performedperformed

Diagnostic testsDiagnostic tests include:include:

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Diagnosis Diagnosis ûû If the pt. has already been diagnosed with If the pt. has already been diagnosed with

epilepsy: anti-epileptic drug (AED) levels may epilepsy: anti-epileptic drug (AED) levels may be tested to ensure that the dosage levels are be tested to ensure that the dosage levels are accurateaccurate

ûû An ECG can exclude cardiac cause of symptoms An ECG can exclude cardiac cause of symptoms or seizure CSF may be tested for infectionor seizure CSF may be tested for infection

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TreatmentTreatment

Current treatment methods can control seizures Current treatment methods can control seizures for approximately 66% of people with epilepsy.for approximately 66% of people with epilepsy. TreatmentsTreatments includeinclude::ûû Anti-epileptic drugs are the most common form Anti-epileptic drugs are the most common form of treatment of treatment ûû Brain surgery is performed if seizures originate Brain surgery is performed if seizures originate in a small, defined area in the temporal or frontal in a small, defined area in the temporal or frontal lobes, but is not common otherwise due to added lobes, but is not common otherwise due to added risk of damaging vital brain functionsrisk of damaging vital brain functions

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Diagnosis & TreatmentDiagnosis & Treatment cont.cont.

ûû Vagus nerve stimulationVagus nerve stimulation-- a vagus nerve a vagus nerve stimulator is implanted into the chest stimulator is implanted into the chest beneath the collarbone, wraps around the beneath the collarbone, wraps around the vagus nerve and stimulates the brain to vagus nerve and stimulates the brain to inhibit seizuresinhibit seizures

ûû Children (and some adults) who donChildren (and some adults) who don’’t t respond to medicinal treatment have been respond to medicinal treatment have been prescribed prescribed a high-fat, high-protein and low a high-fat, high-protein and low carbohydrate diet to produce ketones, carbohydrate diet to produce ketones, which allow the body to use fat instead of which allow the body to use fat instead of glucose for energy. The exact mechanism glucose for energy. The exact mechanism for why this works is unknown.for why this works is unknown. 1818

Epilepsy - TreatmentEpilepsy - Treatment§§ The majority of pts respond to drug therapy The majority of pts respond to drug therapy

(anticonvulsants). In intractable cases surgery may be (anticonvulsants). In intractable cases surgery may be necessary. The treatment target is seizure-freedom and necessary. The treatment target is seizure-freedom and improvement in quality of life!improvement in quality of life!

§§ The commonest drugs The commonest drugs used in clinical practice are: used in clinical practice are: Carbamazepine, Sodium valproate, Lamotrigine Carbamazepine, Sodium valproate, Lamotrigine (first line drugs) (first line drugs) LevetiracetamLevetiracetam, Topiramate, Pregabaline (second line drugs) , Topiramate, Pregabaline (second line drugs) Zonisamide, Eslicarbazepine, Retigabine (new AEDs)Zonisamide, Eslicarbazepine, Retigabine (new AEDs)

§§ Basic rules for drug treatment: Drug treatment should be Basic rules for drug treatment: Drug treatment should be simple, preferably using one anticonvulsant simple, preferably using one anticonvulsant (monotherapy). (monotherapy). ““Start low, increase slowStart low, increase slow““. . Add-on therapy is necessary in some patientsAdd-on therapy is necessary in some patients……

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Witness Response Witness Response When you see someone having a seizure you When you see someone having a seizure you

should: should: ûû Loosen their clothingLoosen their clothingûû Move surrounded objects that the seizing Move surrounded objects that the seizing

individual could hurt him/herself onindividual could hurt him/herself onûû Stay until seizure ends to make sure the person Stay until seizure ends to make sure the person

is okay and can get upis okay and can get up

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