problems in the management of epilepsy

EPILEPSY Medical and surgical

management

Basic Classification

• Primary

– focal

• simple

• complex partial

– generalized

• Secondary– focal– generalized

• Mis: febrile, alcoholic etc

Is it epilepsy?

Features suggestive of epilepsy– Suddenness of attack

– Symptoms of recognized seizure type

– An attack during sleep

– Stereotyped attack

– Injury, incontinence, headache and vomiting

History

• Onset and detail description

• Associated features and modifying factors

• Medical and psychiatric history

• Neurological disorders

• Family history

• Occupation

Clinical Examination

• Skin and vital signs

• Focal neurological deficit

• Features of raised intracranial pressure

• Systemic examination

What blood test in epilepsy?

• Complete blood count

• Blood sugar fasting and post pandrial

• Serum creatinin

• S. Calcium and sodium

• SGPT, bilirubin

EEG in Epilepsy

• To confirm the diagnosis

• To classify the type of seizure

• To locate the focus of discharge

• To find out triggering factors

• To find out associated brain disease

• To monitor anticonvulsant

When to do Neuroimaging?

• Above 25 years of age

• Focal onset or focal neurological sign

• Features of raised intracranial pressure

• Uncontrolled seizure

• Features of focal lesion in EEG

CT or MRI

• CT

– Calcification

– Acute hemorrhage

– Emergency

• MRI– Tumor– Old hematoma– AVM– Temporal atrophy– Granuloma

When to start medication

• Following two seizure within one years

• Following first seizure with

underlying cause

• Employed in dangerous profession

How to start drug treatment?

• Confirm the diagnosis

• Use single anticonvulsant

• Use proper doses

• Loading dose of certain drug in emergency

• Build up dose of others

• Use minimal effective dose

What drug to choose?

Focal/GTCS CBZ, PHY, VALPHB,

Absence VAL, EHT, BNZ

Myoclonic VAL, CLN

Drug level monitoring

• To maintain

minimum dose

• Uncontrolled

epilepsy

• Noncompliance

• Polytherapy

• Drug interaction

• Toxicity

• Hepatic diseases

• Pregnancy

What is the chance of remission?

• 50% Remission off treatment for 20

years

• 20% Remission on treatment

• 30% Seizure on treatment

Catamenial epilepsy

• 10-70% of epilepsy in women

• Estrogen induces seizure

• Progesterone falling levels

• Adjust antiepileptic dose

• Estrogen inhibitors (clomifen)

• Progesterone

Contraceptive in epileptic

• PHY, PHB, CBZ, induces hepatic P450 enzyme and cause contraceptive failure in 6-10%

• Topiramate is weak enzyme induce

• BNZ, LMT, VIG, GPT do no induces P-450

• Estrogen induces seizure

Pregnancy and Epilepsy

• Choice of drug:– All antiepileptics are teratogenic– Use single drug in low dose– Control GTCS – Use Folic acid 1mg 4-6 week before

pregnancy– Use Vit K before delivery to prevent

bleeding

Followup in Pregnancy

Weeks Examination 6-10 AED levels (free and total),

serum folate level 15-16 Maternal serum AFP,

amniocentesis,* AED levels 18-19 Ultrasound for neural-tube

defects 22-24 Ultrasound for oral clefts and

heart anomalies 28 AED levels 34-36 AED levels, maternal

vitamin K

Antiepileptic in breast milk

• Carbamazepine 40% • Ethosuximide 90% • Phenobarbital 36% • Phenytoin 18% • Primidone 70% • Valproic acid 5% • Topiramate,Gabapentin, ??

Lamotrigine

What drug in systemic disease

Liver disease

• Gabapantine

• Phynobarbitone

• Phenytoin

• Benzodiazepine

Renal disease

• Phenytoin

• Phynobarbione

• Benzodiazepine

Febrile seizure

• No seizure for single febrile seizure

• Diazepam orally for recurrent febrile

seizure

• Valproate or phenobarb for recurrent

febrile seizure

Good prognostic signs• Granuloma• Early posttraumatic epilepsy• Mild infrequent seizure• Secondary systemic or toxic

seizure• Benign rolandic epilepsy• Primary generalized epilepsy• Absence seizure• Early treatment

Bad prognostic signs

• Diffuse cerebral disease

• Late posttraumatic epilepsy

• Multiple seizure types

• Complex partial seizure

• Long untreated seizure

• History of Status in the past

When to stop treatment

• Primary generalized seizure with normal

EEG for 2-3 seizure free years

• Taper slowly

• Severe brain damaged needs life long

treatment

• Short course following medical disorder

Intractable seizures

• 20-30% of epilepsy

• Poor compliance

• Inadequate drug doses

• Improper choice of drug

• Inappropriate combination of drugs

• Misdiagnosis of seizure or seizure type

New antiepileptic drugs

1. Clobazam

2. Gabapantin

3. Lamotrigine

4. Topiramate

5. Vigabatrin

6. Falbamate

Clobazam

• Benzodiazepine, anxiolytic

• Weak antiepileptic

• For add on therapy

• Less side effect

• Can be used in children with primay and febrile seizure

• Dose: 0.1-0.5mg/Kg/dayBD

Gabapantine

• First pass metabolism

• No interaction

• Drug level monitoring not required

• Can be use in high doses

• Renal and hepatic failure and transplant patient

Lamotrigine

• Broad spectrum antiepileptic

• Skin rash common, no other significant toxicity

• Can be used in all age as primary and secondary drug

• Dose: 0.5-10mg/kg in two divided dose

Topiramate

• GABArgic

• Efficacy: Partial seizure

• Side effects: fatigue, nervousness, difficulty with concentration, tremor, weight loss, renal stone

• Dose: 50-400mg in two divided doses

Status epilepticus causes

Drug withdrawal 25

Alcohol withdraw 25

Cerebrovascular: 22

Metabolic: 10

Systemic infection 12

Trauma 15

Drug toxicity 15

CNS infection 12

Tumor 8

Congenital lesion 8

Prior Epilepsy 33

Idiopathic 30

Status epilepticus management

• ABCD

• Blood: Electrolytes, CBC, Calcium, Magnesium, BUN, Liver function Anticonvulsant level, Alcohol, Toxicology screen

• If hypoglycemia suspected, give 50% glucose

• Give Thiamine 100 mg iv

• Lorazepam 0.1 mg/kg iv

• Phenytoin 20 mg/kg iv, 50 mg/min

Status management cont.

If seizure persists:

• Phenobarbital 20 mg/kg iv at 50 to 100 mg/min

• Review lab result and correct any abnormality

• CT/MRI: bleed, infection, AV malformations, neoplasm

• Lumbar puncture: if CNS infection suspected

• Blood cultures: Sepsis

For refractory seizure:• Intubation, EEG

monitoring and Pentobarbital 5-15 mg/kg loading over 3 minutes, 0.5 to 5 mg/kg/hr drip or

• Midazolam (Versed) 0.15-0.20 mg/kg loading, then 0.06-1.1 mg/kg/hr drip

• Propofol 1-2 mg/kg loading, then 3-10 mg/kg/h

Surgical Procedures

• Resection of epileptic focus

– cortical resection

– temporal lobectomy

– Amygdylohippocampectomy

• Corpus callosotomy

• Hemispherictomy

Resection of epileptic focus

• Partial seizures

– Temporal origin

– extratemporal origin

• Generalized seizure with identifiable

resectable focus

Corpus callosotomy

• Atonic seizures– frequent episodes– frequent falls and injury– 70% reduction with callosotomy

• Infantile hemiplegic syndrome

• some patients with generalized seizures with epsilateral focus

Evaluation:

• MRI– hippocampal

asymmetry

– temporal lobe abnormality

• CT– interictal CT: may

show enhancement with contrast, slow uptake

• PET– hypometabolism

lateralized to side of temoral lobe focus in 70% of patients

• WADA test– localizes dominant

hemisphere– Amytal

• Video EEG monitoring• Invasive EEG

monitoring

Corpus callosotomy

• leave Ant commissur

• usuallt anterior 2/3

• may produce post op decresed

verbalization

• usually resolves in few days

Temporal lobectomy

• 80% pt have focus in anterior temporal lobe

• most of the pathology in mesial temporal lobe

• Limit of resection:– dominant 4.5 cms– non dominant 6-7 cms

Epilepsy surgery :Outcome

• 2 years post op– 50% seizure free– 80% more than 50% reduction in

frequency

• Dominant temporal lobectomy without intraoperative monitoring– 6% mild dysphasia– major deficit; < 2%