Seizure A sudden surge of electrical activity in brain that usually affects how a person feels or acts for a short time. Some seizures can hardly be noticed, while others are totally disabling.
Epilepsy A condition that affects central nervous system (CNS) had at least 2 seizures not caused by some known medical condition like alcohol withdrawal or extremely low blood sugar. not indicate anything about the cause of the seizures, what type they are, or how severe they are.
Transient loss of consciousness History and Physical Witness account Déjà vu Jamais vu Aphasia Olfactory aura Epigastric sensation Tongue biting Post event delirium Focal neurodeficit Light-headedness Sweating Prolonged standing Precipitants eg.micturition Chest pain Palpitation Slow heart rate Low blood pressure Aphasia Delirium Head turn Automatism Posturing Convulsion Postictal delirium Myoclonus or convulsion after pallor, sweating and collapse Pallor Sweating Slow pulse Low BP Convulsive syncope Seizure Syncope Syncope Seizure
Phase of seizures Preictal phase or aura or warning Ictal phase : simple or complex partial or generalized tonic-clonic seizure Postictal phaseor recovery period : last from seconds to minutes to hours
Precipitants of seizure Sleep and lack of sleep Drugs and alcohol Intercurrent illness : infection, electrolyte imbalance Menstruation Stress and worry Other precipitants-reflex epilepsy
Classification of seizure Partial (focal, localized) seizures Generalized seizures (convulsive or non-convulsive) Unclassified epileptic seizures
Unclassified epileptic seizures - Neonatal seizures - Recurrent status epilepticus - Rare or ‘isolated’ seizures
Epileptic seizure All clinical and laboratory data neuroimaging Seizure description and EEG Etiology Seizure type (s)
Seizure Idiopathic Generalized epilepsy likely Features of focal epilepsy Epilepsy or PNES Provoked seizures Treat cause +/- AED EEG EEG MRI/CT brain Video EEG PNES=psychogenic non-epileptic seizures AED=antiepileptic drug
Laboratory investigation CBC FBS, BUN, Creatinine Electrolyte , Liver function test , Ca+2 Mg+2 Electro-encephalography (EEG) Video EEG Neuroimaging : CT Scan, MRI, MR Spect, PET Special investigation : ammonia, lactate, pyruvate etc.
EEG 30 minute interictal EEG –useful when clinical suspicion of epilepsy Timing is important Within 24 hr of generalized convulsion: 50% have abnormal EEG First 48 hr: 21-34% have epileptiform activity Sleep EEG or sleep-deprived EEG might increase diagnostic yield
Video Monitoring Helpful in determining nature of seizure disorder (epilepsy, convulsive syncope, or psychogenic seizures)
Indication for neuroimaging in patients with seizures Partial seizure Late onset unprovoked seizure (age > 25) Unexplained neurological signs Focal slow waves EEG poor control or new symptoms / signs
Neuroimaging In the absence of trauma: CT and MRI brain for patients presenting with suspected first unprovoked seizure or with a focal neurological deficit. MRI is preferable for looking for neuronal migrational disorders, major malformations, vascular anomalies, tumors
The causes of epilepsy Genetic factor Congenital abnormalities Trauma and the effect of craniotomy CNS infection Cerebrovascular disease Cerebral tumors Alzheimer’s disease and other degenerative disease Others
52 year old woman with intractable seizure PET scan
PET using F-18 FDG-- Decreased FDG uptake in both temporal lobes, right worse then left but otherwise relatively symmetric
What to do? Generalized seizure Loosening the patient’s clothing Lower the patient gently to the floor, turn them onto their side and cushion head Nothing is put into the mouth Remove any items that could cause injury
What to do? ---Generalized seizure When the seizure is over, allow the patient to rest or sleep If they are able to return to their feet, help them home Obtain medical help if they continue to experience breathing problems once the seizure is over, or if the seizure lasts a long time(over 10 mins), or when another attack quickly follows the first
What to do? Partial seizures Stay with the patients throughout the seizure Protect them from any dangerous object Taking care not to restrain them in anyway
Choose a drug : considering the following factors The seizure type and prognosis Age The possibility of pregnancy Toxicity Drug interaction Price
RISK OF RECURRENT SEIZURE The recurrence risk follow a first unprovoked seizure 27%-52% 50% recurrence occur within 6 months over 80% within 2 years of initial seizures twice as likely to have another seizure if you have a known brain injury or brain abnormality.
RISK OF RECURRENT SEIZURE(cont) If you do have two seizures, there's about 80% chance that you'll have more.
Factors predictive of a high rate of seizure recurrence after the first unprovoked seizure
Counseling before treatment 1. Aims of treatment 2. Prognosis and duration of the expected treatment 3. Importance of compliance 4. Side effects
Starting antiepileptic treatment Prospective risks Usual clinical Factors that may modify of epilepsy practice usual practice Single seizure No treatment Progressive cerebral disorder (clinically Dx) Clearly epileptic EEG 2 or more seizure Monotherapy Seizures widely separated (clinically Dx) in time (> 1 year) Identified precipitating, factors (eg, drugs, alcohol,reflex stimuli) Probability of poor compliance (eg, personality disorder) Attitude of patients/parents
AEDs Drug interaction with AED and other drugs: via effect on hepatic CYP450 enzyme system PB, primidone, PHT, CBZ induce CYP enz. : Accelerate breakdown of many prescribed lipid-soluble drugs metabolized by the same system: OCP, cytotoxic, antiarrythmic, warfarin VPA is a weak CYP enz. Inhibitor: Slow clearance of other AEDs such as PHT, LTG. Newer AEDs : less likely to interfere with hepatic metabolism. GBP, LEV,PGB,VGB do not undergo hepatic metabolism
Newer AEDs Adjunctive treatment of refractory epilepsy Some of these AEDs: LTG, GBP, OXC, TPM have also demonstrated efficacy as monotherapy
Adverse prognostic factors Symptomatic etiology, identifiable brain pathology Partial-onset seizures or Atonic seizures Late-onset or first-year epilepsy Specific epilepsy syndrome (particularly JME) Abnormal EEGs Multiple seizure types in the same patient Additional mental or motor handicap Long duration or severe epilepsy prior to treatment Poor initial response to treatment
Features common to the surgically privileged seizure disorders Presence of a well-circumscribed structural lesion on the MRI (lesional epilepsy) Presence of well-localized interictal epileptiform discharged on the EEG Clinical features of habitual seizures indicating focal onset Absence of discordance between above feature Focus localized by above features is surgically accessible and involves little or no eloquent cortex Absence of other potentially epileptogenic abnormalities
Status epilepticus A condition in which epileptic activity persists for 30 minutes or more
Common etiologies for status epilepticus in children and adolescents Idiopathic Acute symptomatic Electrolyte disturbance Encephalitis Head trauma Remote symptomatic Past stroke CNS infection Cerebral palsy Progressive encephalopathy Tuberous sclerosis Other neurodegeneration Febrile
Recommendations for managing Women With Epilepsy Before Conception Educate the family regarding risks Review classification of epilepsy Determine most appropriate medicine for seizure control
Determine need for continued medication - may discontinue if seizure-free for 2 or more years - do not discontinue medication if epilepsy syndrome suggests continued need for treatment Reduce medicines to monotherapy, lowest dose possible Start folic acid 1 mg/day Eliminate other risk factors – smoking, drugs, alcohol
After conception Do not change antiepileptic medication Refer for prenatal care Prescribe vitamins, including folic acid Check ‘free’ drug levels every trimester and change doses as needed Evaluate for neural tube defects at 12 to 16 weeks (ultrasound, alpha-fetoprotein, amniocentesis)
Consider vitamin K predelivery Check antiepileptic drug levels prior to delivery and increase doses if needed