7/30/2019 9716Neonatal Seizures

1/19

Neonatal Seizures and

management

Dhaka Sishu hospital

Bangladesh

7/30/2019 9716Neonatal Seizures

2/19

Objectives

Introduction

Types/ Differential Diagnosis

Investigations

Management

Areas of Uncertainty in Clinical Practice

Prognosis

http://rwh.org.au/nets/handbook/index.cfm?doc_id=602http://rwh.org.au/nets/handbook/index.cfm?doc_id=602http://rwh.org.au/nets/handbook/index.cfm?doc_id=602http://rwh.org.au/nets/handbook/index.cfm?doc_id=602http://rwh.org.au/nets/handbook/index.cfm?doc_id=602http://rwh.org.au/nets/handbook/index.cfm?doc_id=602http://rwh.org.au/nets/handbook/index.cfm?doc_id=602http://rwh.org.au/nets/handbook/index.cfm?doc_id=602http://rwh.org.au/nets/handbook/index.cfm?doc_id=602http://rwh.org.au/nets/handbook/index.cfm?doc_id=602http://rwh.org.au/nets/handbook/index.cfm?doc_id=602http://rwh.org.au/nets/handbook/index.cfm?doc_id=602http://rwh.org.au/nets/handbook/index.cfm?doc_id=602http://rwh.org.au/nets/handbook/index.cfm?doc_id=602

7/30/2019 9716Neonatal Seizures

3/19

Introduction

Neonatal seizures are paroxysmalalterations in neurological function. This

definition allows the inclusion of clinical

seizures associated with EEG

abnormalities as well as paroxysmal

clinical activities (lip smacking, cycling

etc.) that are not associated with EEG

alterations.

7/30/2019 9716Neonatal Seizures

4/19

Relatively high incidence of seizures (13

per 1000 term infants and in preterm-10

to15/1000). Rarely idiopathic.

7/30/2019 9716Neonatal Seizures

5/19

Aetiology of neonatal seizures:

The main causes are: Hypoxic-ischaemic encephalopathy (HIE)

Intracranial haemorrhage : subarachnoid (term >preterm), subdural (term infants with difficult

deliveries) and peri/intraventricular (preterminfant)

Cerebral infarction (stroke) : term infants

Congenital CNS structural abnormalities /

cortical dysplasia (neuronal migration disorderscausing cerebral cortical dysgenesis).

Intracranial infection : meningitis > encephalitis

7/30/2019 9716Neonatal Seizures

6/19

Less common causes are:

Inborn error of metabolism: amino and organic

acidopathies, often seen after the infant startsfeeding.

Electrolyte disturbances: hypoglycaemia,hypocalcaemia, hypomagnesaemia, hyper- andhypo- natraemia,

Pyridoxine deficiency Neonatal drug withdrawal

Trauma: delivery and non accidental injury

Benign familial neonatal seizure syndromes: AD, szoften start on day 2-3 and cease 6 months

Benign idiopathic neonatal seizures at day 5 of life(ie, fifth day fits)

Unknown aetiology / idiopathic : 2 - 5%

Progressive epileptic syndromes in the first year oflife with onset in the neonatal period

7/30/2019 9716Neonatal Seizures

7/19

TYPES

7/30/2019 9716Neonatal Seizures

8/19

Type Clinical manifestation Comments

Subtle

50-75%

Eye signs: staring, deviation, blinking

etc

Buccal-oral-lingual: chewing,sucking, lip smacking

Limbs: cycling, swimming rowing

Systemic: apnoea, blood pressure

alterations

It may be difficult to differentiate

subtle seizures from extremes

of normal behavior. Many subtle

seizures are thought to arisefrom the basal ganglia as a

result of diminished cortical

inhibition. Further depression of

the cortex with anticonvulsants

may not alter these seizures

Clonic

23-40%

Repetitive jerking, usually involveone limb or one side of the body

at 1 4 times per second.

May be a clue to an underlying focal

neuropathology e.g.

hemorrhage or cerebral

infarction

Myoclonic

8-18%

Rapid isolated jerking of muscles.

Focal, multifocal or generalizedD/D- benign sleep myoclonus.

Seen in drug withdrawal (especially

opiates). If it occurs during sleep

then it is probably "benign

neonatal sleep myoclonus". Canalso occur in a very severe form

of encephalopathy.

Tonic

2-10%

Sustained posturing of the limbs or

trunk or deviation of the head. It

may mimic decerebrate or

decorticate posturing. Only 30%have EEG correlates.

Often difficult to treat with

anticonvulsants

7/30/2019 9716Neonatal Seizures

9/19

Movement Description

Jitteriness

Symmetrical rapid movements of the hands and

feet

Stimulus sensitive, and may be initiated by

sudden movement or noise or spontaneous.

Suppressed by holding the limb.No associated eye movements

Benign neonatal

sleep

myoclonus

Bilateral or unilateral jerking during sleep

Occurs during active sleep

Not stimulus sensitive

Often involve upper > lower trunk

Differential diagnosis

7/30/2019 9716Neonatal Seizures

10/19

Management

Immediate management includes-Stabilization-evaluation of ventilation and

perfusion.

Identification of the cause and specifictreatment.

If needed, administration of an

antiepileptic drug (AED) to prevent seizurerecurrence.

7/30/2019 9716Neonatal Seizures

11/19

Investigations:

All newborns with seizures :

Blood glucose level

Electrolytes: Na+, Ca2+, Mg2+

Full blood count

Cranial ultrasound: to exclude gross

CNS pathology, but is not effective at

detecting subdural and epidural bleeds

or identifying parenchymal injury.

7/30/2019 9716Neonatal Seizures

12/19

Further investigations :

Acid base status

Blood culture

Lumbar puncture: for CSF study.

Specimens for virology and congenital infections:TORCH (toxoplasmosis, rubella, CMV, herpes)

Metabolic screen: urine for amino and organic acids

Metabolic screen: blood for ammonia, lactate, pyruvate.

Neurophysiology: formal 12 lead EEG, continuousEEG(BRAINZ monitor)

Neuroimaging: CT, MRI

7/30/2019 9716Neonatal Seizures

13/19

Anticonvulsant medication: Indication for treatment of clinical seizures:

Prolonged > 3min

Recurrent > 3 in 1hour Associated with cardiorespiratory compromise.

Therapy:

Start with Phenobarbitone. If seizures are not controlled withmaximum phenobarbitone, add Phenytoin.

Drug levels should be monitored to determine maintenance dosagesbecause of the variable pharmacokinetics in this age group.

If a combination of phenobarbitone and phenytoin is ineffective, thenthe options for achieving complete seizure control become limited.Clonazepam as a third line agent, .. In a recent report. Lignocaineappeared to be superior to clonazepam or midazolam.

A trial ofPyridoxine should be performed in conjunction with EEGmonitoring if pyridoxine deficiency is suspected in an infant withintractable seizures who does not have an underlying aetiologydetermined. Documenting cessation of seizures and normalisation ofthe EEG within minutes of IV pyridoxine often makes diagnosis.

7/30/2019 9716Neonatal Seizures

14/19

Anticonvulsant Indication for

treatment

Loading dose Maintenance Other

consideratio

ns

Phenobarbitone Seizures duration:

3 minutes

OR

Seizure

frequency: 3

per hour

20 mg/kg IV over 30 minutes.

If initial dose is ineffective an

additional 510 mg/kg can

be administered every 5

minutes, up to a total of 40

mg/kg

4 mg/kg/dose

IV/ oral

every 12h

Start 24 hours

after the

loading

dose

Therapeuticlev:4

0130

mol/L

Needs

cardiorespira

tory

monitoring

Phenytoin Inadequate response

to

phenobarbitone

20 mg/kg IV over 30 minutes 4 mg/kg/dose

IV every

12 hStart 12 hours

after the

loading

dose

Therapeutic level:

40-80

mol/LNeeds

cardiorespira

tory

monitoring

Clonazepam Inadequate response

to

phenobarbitone

and phenytoin

0.025 mg/kg/dose IV stat 0.025

mg/kg/dos

e every 8

hours

Needs

cardiorespira

tory

monitoring

Pyridoxine Intractable seizures

with no

underlying

aetiology

determined

100 mg IV or IM stat

(test dose)

50100 mg

daily oral

Pyridoxine trial

(s) to be

performed

with EEG.

7/30/2019 9716Neonatal Seizures

15/19

Areas of Uncertainty in Clinical Practice

Duration of therapy and decision to stop anticonvulsantmedication is entirely empiric and should be judged onan individual basis taking into account the neurologicalexam, aetiology of seizures and interictal EEG.

Withdraw anticonvulsants once seizures are controlled

and neurological examination is normal. There is no indication that prolonged treatment of

anticonvulsant therapy reduces the risk for the laterdevelopment of epilepsy.

The only recommendation for continuing anticonvulsanttherapy (phenobarbitone 3-4 mg/kg/day) is in the settingof profound neonatal encephalopathy or severe braininjury and then only for 6-8 weeks.

7/30/2019 9716Neonatal Seizures

16/19

Consequences

Short term: Prolonged seizures maycause

Hypoxia Arrhythmia

Lactic acidosis Hypoglycemia Hyperkalemia Hyponatremia

Myoglobinuria Hyperpyrexia

7/30/2019 9716Neonatal Seizures

17/19

Long term: Prognosis depends on the:

Aetiology of the seizures.

Neurological exam: Persistent neurological abnormalities are associatedwith poor outcome

Gestational age: Adverse neurodevelopment outcome of cognitive changes,developmental delay , cerebral palsy . Seen in 20 40% of term and up to75% of preterm infants. [9.3% in term & 33.3% in preterm babies with

asphyxia (HIE-2,3), Mahbub et al DSHJ;2004;20:30-33]

Seizure characteristics: Increased likelihood of adverse / poor outcomeassociated with

Seizure type: Subtle, generalised or 2 or more seizure types.

Prolonged or poorly controlled.

EEG background: If there is persistent low voltage or burst suppressionpattern this correlates with poor neurodevelopmental outcome in 65 to 90%.

7/30/2019 9716Neonatal Seizures

18/19

Summary Neonatal seizures are relatively common and rarely

idiopathic

There are four different types of clinical seizures

Seizures must be differentiated from jitteriness andbenign neonatal sleep myoclonus

Treat with anticonvulsants if the seizure is prolonged(longer than 3 minutes), frequent or associated with

cardiorespiratory disturbance

70% of seizures will abate with phenobarbitone only

7/30/2019 9716Neonatal Seizures

19/19