15. Epilepsy 2.ppt

Epilepsy Management Diagnosis of Epilepsy • Clinical- History & examination • Laboratory Investigations • Intensive if occuring for the first time in adult life • To confirm the diagnosis (including the type) and to define a cause. Routine investigations • Metabolic: BG, S. electrolytes, Ca, M...

Epilepsy Management Diagnosis of Epilepsy • Clinical- History & examination • Laboratory Investigations • Intensive if occuring for the first time in adult life • To confirm the diagnosis (including the type) and to define a cause. Routine investigations • Metabolic: BG, S. electrolytes, Ca, Mg, RFT, LFT • Infection / inflammatory: Blood count, ESR, CRP, Serology for syphilis, HIV, collagen diseases (blood) CXR, CSF examination • EEG: diagnosis including the type; pts with unprovoked first fit ; for all Not very sensitive, only 50% have abnormal interictal EEG; Sensitivity improved by sleep. • Imaging (MRI, CT) : structural cause; in late onset (after 20 yrs), focal type (clinical & EEG), abnormal clinical signs, refractory epilepsy EEG electrodes EEG EEG EEG waves EEG • a- normal • b- petit mal • c- delta waves Special investigations • Sleep EEG • Ambulatory EEG • EEG with simultaneous video • EEG with special electrodes (foramen ovale & subdural) Treatment • Immediate care • Explanation • Medical treatment (Drug therapy) • Psychiatric & Social factors ( restrictions) Immediate care • First aid : - move away from danger - after convulsions cease turn into recovery position (semiprone) - ensure clear airway - do not insert anything into the mouth - do not leave the patient alone • Medical : - ensure airway & give oxygen - give IV anticonvulsant (diazepam) - take blood for AED level. First aid Explanation To the patients & relatives; • Nature & cause, • First aid measures, • Prognosis (good control expected in 80%) Drug therapy • Consider after > 1 seizure & with patient’s consent; infrequent fits - may not agree • Dose regimen should be simple using a single drug; Majority (80%) respond to monotherapy, if the choice & dosage is correct • Monitor blood level of AED if continue to have fits on treatment or features of toxicity develops (phenytoin & carbamazepine) Guidelines for anticonvulsant therapy • Start with one first line drug • Start with low dose & gradually increase to effective control / side effects. • Check compliance • If first drug fails add second drug gradually withdrawing the first • Try 3 drugs singly before using combinations • Do not use > 2 drugs in combination • If above fails consider occult structural / metabolic lesion Epilepsy - Treatment  The majority of pts respond to drug therapy (anticonvulsants). In intractable cases surgery may be necessary. The treatment target is seizure-freedom and improvement in quality of life!  The commonest drugs used in clinical practice are: Carbamazepine, Sodium valproate, Lamotrigine (first line drugs) Levetiracetam, Topiramate, Pregabaline (second line drugs) Zonisamide, Eslicarbazepine, Retigabine (new AEDs)  Basic rules for drug treatment: Drug treatment should be simple, preferably using one anticonvulsant (monotherapy). “Start low, increase slow“. Add-on therapy is necessary in some patients… Choice of drug • Primary GTC - Valproate (first line) - Carbamazepine, Lamotrigine (second) - Phenytoin, Gabapentine (third) • Absence - Ethosuximide (first) - Valproate (second) - Lamotrigine (third) • Myoclonic seizure - Valporate (first) - Clonazepam (second) • Partial & secondary GTC - Carbamazepine, Valporate, Phenytoin - Lamotrigine (second) - Gabapentine, Clobazam (third) SIDE EFFECTS Carbamezapine Transient leucopenia, hyponatremia from SIADH; rare aplastic anemia and hepatitis. Stevens-Johnson Valproate Tremor, wt. gain, alopecia, thrombocytopenia (dosedependent), benign elevation of LFTs common. Rare fatal hepatitis and pancreatitis. Established risk of teratogenicity; neural tube defects. Lamotrigine Rash in 1:1000 overall, ?~1:50 in children, esp with rapid titration Phenytoin Gum hypertrophy, hirsutism coarse features. Cerebellarataxia/atrophy, peripheral neuropathy with very Gum hypertrophy Drug interactions • All major AEDs (apart from valporate) induce liver enzymes & may cause OCP failure & warfarin failure • Alcohol Withdrawal of AED • Complete control for 3 years; childhood onset- better controlled; adult onsetfocal, likely to recur, prefer to continue • EEG is a poor predictor • Gradually over 6-12 months Restrictions Restrictions • Avoid working at height / with heavy machinery, fire, water • Take bath when relative is around / do not lock the bathroom • Recreational activities in company of someone • Discourage cycling until 6 months freedom from seizure Psycological factors Surgical treatment • Resection • Stereotactic surgery • Corpus callosum section VAGAL STIMULATION Prognosis • Generalised seizures are better controlled than partial seizures • Presence of structural lesion, continuing EEG abnormality – complete control less likely • 20 yrs after diagnosis - 50% free from fits & off treatment - 20% fit-free, but on treatment - 30% fits continued on treatment Status epilepticus • Major status (GTC) is life threatening; Partial seizures- epilepsy partialis continua • Causes: - Abrupt withdrawal of anticonvulsant (primary) - acute metabolic disturbance - major structural lesion Treatment • Immediate care • Secure IV line & send blood for glucose, electrolytes & save for future analysis (drug) • Maintain airway & 50 ml 50% D • IV Diazepam / Lorazepam • Transfer to ICU & monitor • IV phenytoin; if seizures continue- IV phenobarbitone • If above measures failGA with thiopentone or propofol / IV midazolam • Investigate the cause • Long term oral drug program. Epilepsy & Pregnancy Epilepsy & pregnancy • Phenytoin, carbamazepine & barbituratesOCP failure • 3rd trimester – fall of plasma anticonvulsantepilepsy may worsen • Anticonvulsants- teratogenecity Phenytoin, CBZ- Cleft lip & palate, cardiac Valporate- neural tube defects • Risk to fetus from uncontrolled maternal seizure is > teratogenic effect THANK YOU