وبركاته الله ورحمة عليكم السالم

By: Dr. Mohamed Abunada

Head Pediatric Neurology DepartmentEl Rantisi specialized Pediatric

Hospital - Gaza

CONVULSIONS

INTRODUCTION

• The word convulsion (or seizure) describes an involuntary violent spasm, or a series of jerking of the face, trunk, or extremities with or without loss of consciousness, sensory, autonomic or behavioral disturbances.

• The word epilepsy describes a syndrome of recurrent unprovoked, seizure unrelated to fever or to acute cerebral insult.

INTRODUCTION

• Epilepsy is a symptom complex arising from disordered brain function that it self may be secondary to a variety of pathologic processes.

• Status epilepticus (SE) is a severe form of seizure activity lasting more than 30 minutes or recurrent seizures with failure to recover consciousness between repeated attacks.

Common causes• Head injury• CNS infection• Toxins• Metabolic disorder• Systemic disorders (endocrine, renal, hepatic)• Degenerative brain disorder• Cerebrovascular disease• Pyridoxine defeciency• Hereditary disorder• Specific epilepsy syndromes

EEG and NEUROIMAGING

A routine interictal (between seizures) EEG will show an epileptiform abnormality in only 60% of patients with epilepsy. Procedures that may activate a convulsion during the EEG include eye closure, hyperventilation and sleep deprivation. Angiography for excluding cerebrovascular accident. CT & MRI to exclud structural brain disorderOther investigations include metabolic, toxic and septic screen.

PATHOPHYSIOLOGY OF CONVULSIONS

During a convulsive fit:-  Cerebral O2 consumption increases to 300%- Cerebral blood flow increases to 900%.

The previous changes lead to:-  Hypoxic ischemic brain injury.- Metabolic brain injury.- Structural brain injury.

PATHOPHYSIOLOGY OF CONVULSIONS

Therefore systemic pathophysiological changes may include:

• CNS: Cerebral ischemia.Brain edema.Cerebral hemorrhage.Brain damage.

PATHOPHYSIOLOGY OF CONVULSIONS

Respiratory:Airway obstruction.Apnea.Pulmonary edema.Aspiration pneumonia.

CVS:Shock.Heart failure.Hypertension.Cardiac arrest.

 

PATHOPHYSIOLOGY OF CONVULSIONS

• Metabolic: Metabolic acidosis. Hyperpyrexia. Hypoglycemia, hyponatremia.

• Short repetitive fits are more serious than prolonged fits as long fits induce cerebral vascular compensatory changes better than short repetitive fits.

Classification of convulsions• Partial seizures: Simple partial seizures. Complex partial seizures. Partial seizures with secondary generalization.• Generalized seizures: Generalized typical absence seizure (petit mal). Generalized atypical absence seizure (atypical petit mal). Generalized myoclonic seizure. Generalized tonic, clonic,or tonic-clonic seizure (grand mal) Infantile spasms (with hypsarrhythmic EEG)

Simple partial seizures

Consciousness retained Asynchronous. Clonic or tonic motor movement (such as eye twitches). Rarely persisting longer than 10-20 seconds. The EEG characteristically shows unilateral spikes or sharp waves in the anterior temporal region.

Complex partial seizures

consciousness impairedThe average duration is 1-2 minutes.The aura signals the onset of convulsion in 30%

of children. In the aura, the child complains of epigastric

discomfort, fear, or unpleasant feeling.

Complex partial seizures

Automatisms are repetitive stereotyped behaviors that occur in 50-70% of children with complex partial seizures.

Automatism follows loss of consciousness and may include lip smacking, chewing, repetitive swallowing, excessive salivation, picking and pulling at clothing.

The EEG is characterized by sharp waves or spike discharges in the anterior temporal or frontal lobe, or by multifocal spikes.

Partial seizures with secondary generalization

During the partial Seizure the epileptiform discharge may spread from the temporal lobe throughout the cortex causing a generalized tonic-clonic convulsion.

Generalized typical absence seizure(Petit mal)

Onset at age more than 3 years.  Brief (5-20 sec.) lapses in consciousness, speech or motor activity.  Not accompanied by an aura.  Hyperventilation for 3-4 minutes frequently induces a seizure.  The EEG is characterized by 3/sec spike and generalized wave discharges.

Generalized myoclonic seizures

Brief repetitive symmetric muscle contractions with loss of body tone.Cause the child to fall because of a sudden loss of postural tone.

Generalized tonic, clonic, or tonic-clonic seizures (grand mal)

Sudden loss of consciousness.   Loss of bladder control.   Perioral cyanosis.   Followed by 30-60 minute peroid of deep sleep and postalictal headache. 

Infantile spasms (with hypsarrhythmic EEG)

Begins in the first year of life. Characterized by large myoclonic (salaam) spasms.  There are at least 3 types of spasms: flexor, extensor and mixed. High incidence of subsequent retardation.

FEBRILE CONVULSION

Definition: convulsion associated with fever between 6 months and 5 years of age without evidence of intracranial infection or other CNS pathology..  The most common convulsive disorder of childhood.The most common age of onset is 14-18 months.  The convulsion is usually generalized tonic- clonic of few seconds duration. The problem always resolves without sequelae.

FEBRILE CONVULSION

Exceedingly long febrile convulsions may carry some risk of brain damage.

A history of febrile convulsion in a close relative is a risk factor for the development of febrile convulsion.

Recurrence of convulsion after the first febrile convulsion is common (>33%).

Recurrence is more common in young infants.Fewer than 5% of children who have febrile

convulsion develop epilepsy.

Risk factors for developing epilepsy

Family history of afebrile convulsion.Complex first febrile convulsion. Initial febrile seizure at age < 9 months.Prior neurologic or developmental abnormalities

existed.

Types of febrile convulsion

    Simple febrile convulsions Complex febrile convulsions

Simple febrile convulsions

Brief (< 15 minutes).Occurs as a solitary event (one attack/24

hours).Typically generalized tonic-clonic

convulsions.Followed by a brief period of postictal

drowsiness.

Complex febrile convulsions

Long (> 15 minutes).Repeated convulsions for several hours or days. May be focal, or generalized tonic-clonic

convulsions.Followed by a long period of postictal

drowsiness.

EEG is indicated for        The patient with atypical seizure. The child at risk for developing epilepsy. 

Lumbar Puncture

LP is indicated for all infants aged < one year with febrile convulsions.

LP should be considered for any patient aged 12-18 months if a primary focus is not found.

For age > 18 months meningeal signs are typically present. LP is deferred if such signs are not present.

Prophylactic anti-epileptic treatment

     

Following a febrile seizure, treatment with prophylactic anti-epileptics may be considered in: The very young child if febrile seizures recur. Children with pre existing neurologic abnormalities. Children with complex febrile seizures.

Treatment of febrile convulsion

Active measures to control fever.   Treatment of the cause.   Reassurance of the parents.   Oral diazepam 0.3 mg/kg/every 8 hours (1 mg/kg/day) reduces the risk of febrile seizures by nearly %50. It is administered at the onset of each febrile illness for 2-3 days.

NON FEBRILE CONVULSIONS:

Indications for anticonvulsant therapy Petit mal, Myoclonic seizures, and Infantile spasms. Two or more unprovoked seizures occur within 6-12 months. A single afebrile tonic-clonic seizure has a high probability of not recurring, therefore anticonvulsant is not advised following the initial tonic-clonic seizure. Prolonged convulsions may require large and repeated doses of anticonvulsant, and consequently mechanical ventilation.

ANTICONVULSANT CHOICE BY SEIZURE TYPE: Seizure typeDrug of choiceSecond lineor adjunctive drugs

Simple partial seizure

PhenobarbitonePhenytoin

Carbamazepine

Valproic acid

Complex partial seizure

CarbamazepinePhenytoin

PhenobarbitoneValproic acid

Petit malEthosuximideValproic acid

ClonazepamPhenobarbitone

Infantile spasmACTHValproic acidClonazepam

PhenytoinPhenobarbitone

Grand malPhenobarbitoneCarbamazepine

Valproic acid

Febrile convulsions

PhenobarbitoneValproic acid

Neonatal seizurePhenobarbitonephenytoin

Valproic acid

COMMON ANTICONVULSANT DRUGS: DrugHalf life(hour)

Dose(mg/Kg)

Therapeutic range (μ/ml)

Side effects

Phenytoin24-502.5/12 hrs10-20Rash, hirsutism, gingival

hyperplasiaPhenobarbitone 60-921.5-2.5/12

hrs10-45Lethargy,

irritability,hyperreactivity

Carbamazepine9-155-10/8-12 hrs

3-11Blurry vision, granulocytopeni

a, liver dysfunction

Ethosuximide20-6010-15/12 hrs40-120Hiccups,

blood dyscriasisValproic acid8-158-20/8-12

hrs50-120Alopecia,

hepatotoxicityClonazepam24-480.01-0.1/12

hrs10-60Ataxia,

hypersalivation.

THERAPEUTIC DRUG LEVEL MONITORING

At the initiation of therapy to ensure achievement of therapeutic range. During times of accelerated growth. If the seizures are out of control.

STATUS EPILEPTICUS:

SE is defined as continuous seizure activity for at least 30 minutes, or recurrent seizures without a return to base line level of consciousness between seizures.

Generalized convulsive SE is the most common type in pediatric population.· 

The etiologies of SEThe etiologies of SE can be organized into 4

broad categories:Atypical febrile seizures.

Acute CNS disorders (trauma, infection, metabolic)

Idiopathic symptomatic epilepsy.

Chronic, or progressive neurological disorders.

STATUS EPILEPTICUS

Morbidity is more likely in individuals with severe CNS pathology.

Seizures of prolonged duration may be associated with increased morbidity.

Mortality is often related to the underlying etiology, and, therefore highest mortality is associated with tumors.

Goals of treatment

Goals of treatment can be organized into 4 broad categories:

Initial stabilization.

  Terminate seizure activity.

  Prevent seizure recurrence.

  Establish a diagnosis and initiate therapy for treatable causes.

TREATMENT STRATEGY

Initial stabilization.

First line ( benzodiazepines).

Second line (phenytoin & barbiturates).

Third line (Refractory status epilepticus).

Unique therapeutic modalities

Initial stabilization

• Establish airway, • apply oxygen and ventilation, • establish IV access• take samples for initial studies.   

First line ( benzodiazepines)Diazepam: 0.5 mg/Kg (maximum 10 mg) slow

IV (not > 1mg/min) or per rectum (undiluted).

Lorazepam: 0.05-0.1 mg/Kg intravenous, per rectum or sublingual.

Midazolam: 0.1-0.2 mg/Kg IV or IM

Benzodiazepines dose may be repeated every 5 minutes up to 3 doses. Monitor respiration.

Second line (phenytoin & barbiturates)

• Phenytoin: 20 mg/Kg slow IV (no faster than 1 mg/Kg/min with a maximum of 50 mg/min). An additional 5 mg/kg may be given prior to initiation of barbiturates.

Monitor heart rate and blood pressure.

Phenobarbitone: 15-20 mg/Kg slow IV (no faster than 1 mg/Kg/min).

Monitor blood pressure and respiration.

Third line (Refractory status epilepticus)

 RSE: Ongoing seizure activity that fails to respond to initial doses of benzodiazepines and loading doses of phyenytoin and phenobarbitone. Phenobarbitone: use repeated bolus doses of 5-20 mg/Kg, spaced by enough time to allow penetration of the drug to the CNS (approximately 30-60 min).Maximum doses administered in 24 h ranged from 30-120 mg/Kg (median 60 mg/Kg) and the maximum blood levels achieved were 80-350 μ/ml. 

Third line(Refractory status epilepticus)

Midazolam: use a bolus of 0.2 mg/Kg followed by infusion of 0.2/Kg/h, and increase the dose until seizures are terminated.

Monitor heart rate, BP and ECG.Pentobarbital (pentothal): use repeated doses

of 3-5 mg/Kg slow IV (no faster than 50 mg/min) followed by infusion of 2-10 mg/Kg/hour.

Monitor heart rate, BP and respiration.

Unique therapeutic modalities

General anaesthesia probably acts by reversing cerebral anoxia and the concomitant metabolic abnormalities allowing the previously anticonvulsants to exert their effect.

General anaesthesia needs to be administered in an operating room for long periods with anaesthesia equipment.

First line(Reception room)

Diazepam 0.5 mg/kgSlow iv (max. dose 10 mg)

Undiluted per rectum

Or, lorazepam 0.05-1 mg/kgSlow iv

Per rectumsublingal

Or, midazolam 0.2 mg/kgSlow iv

intramuscular

Second line(General ward)

Phenytoin 15-20 mg/kgSlow iv

No faster than 1 mg/kg/min.Maximum 50 mg/min

If seizures persistPhenobarbitone 15-20 mg/kg

Slow ivNo faster than 1 mg/kg/min

Third line(Intensive care unit)

Midazolam 0.2 mg/kgSlowly iv bolus dose

Followed by 0.2 mg/kg/hBy iv infusion titrated to effect

If seizures persistPhenobarbitone 5-20 mg/kg

Slow iv repeated boluses every hourUp to 30-120 mg/kg/day

If seizures persist pentobarbitone (pentothal) 3-5 mg/kgSlow iv repeated boluses every 30-60 min

Followed by 2-10 mg/kg/h iv infusion titrated to effect

Fourth line(Unique therapeutic modalities)

Paraledhyde 150 mg/kg intramuscularOr, 300 mg/kg per rectum

Moderate hypothermia

General anasthesiaHalothane, or isoflurane

Lidocaine 1-2 mg/kgSlow iv bolus

Followed by 2 mg/kg/h iv infusion

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