Electrical (non-convulsive) status epilepticus

Paediatric Neurology update 2014

28 August 2014

Ahmad Rithauddin bin Mohamed

Paediatric Neurologist, IPHKL

Non-convulsive status epilepticus (NCSE)

a state of ongoing (or non-recovery between) seizures without convulsions, usually for more

than 30 min

Intensive care setting

‘comatose’, ‘encephalopathic’ post convulsive status

Out-patient setting

‘not quite right’ neuroregression

Case example 1

• 5 yr old, unwell with fever and diarrhoea

• Had 2-3 brief seizures initially, then convulsive status epilepticus after several hours

• Continued to have intermittent seizures while ventilated (2/52)

• Post extubation – brief eye deviation, remained encephalopathic

after 20 seconds

NCSE in febrile illness related epilepsy syndrome (FIRES)

How common is NCSE in ICU setting?

% of electrographic seizures and status epilepticus in PICU

ove

rall

IPH

KL

North American Paediatric Critical Care EEG Group, 50 consecutive EEG monitoring at each centre

ove

rall

Sanchez et al, 2013

% of electrographic seizures and status epilepticus in PICU

ove

rall

IPH

KL

ove

rall

IPH

KL

Khoo TB, 2014

Prevalence of NCS/NCSE

• Sanchez 2013 (11 centres, N=550)

– 162/550 (29%) had electrographic seizures

– 61/550 (11%) had electrographic status epilepticus

– 114/550 (21%) had non-convulsive (+/- convulsive) seizures

• Khoo 2014 (IPHKL, N=50)

– 11/50 (22%) had electrographic seizures

– 4/50 (8%) had electrographic status epilepticus

– 8/50 (16%) had non-convulsive (+/- convulsive) seizures; 4/50 (8%) had NCSE

Prevalence of NCS/NCSE

• Sanchez 2013 (11 centres, N=550)

– 162/550 (29%) had electrographic seizures

– 61/550 (11%) had electrographic status epilepticus

– 114/550 (21%) had non-convulsive (+/- convulsive) seizures

• Khoo 2014 (IPHKL, N=50)

– 11/50 (22%) had electrographic seizures

– 4/50 (8%) had electrographic status epilepticus

– 8/50 (16%) had non-convulsive (+/- convulsive) seizures; 4/50 (8%) had NCSE

4 FIRES, 1 NMDA encephalitis, 1 viral encephalitis, 2 epilepsy exacerbation

Predictors of NCSE

• Greiner 2012 – witnessed seizure, abnormal brain imaging

• McCoy 2011 - epilepsy, witnessed seizure, acute structural brain injury, interictal discharges on EEG

• IPHKL – witnessed seizure

Predictors of NCSE

• Greiner 2012 – witnessed seizure, abnormal brain imaging

• McCoy 2011 - epilepsy, witnessed seizure, acute structural brain injury, interictal discharges on EEG

• IPHKL – witnessed seizure

ADC

DWI

Acute stroke

Predictors of NCSE

• Greiner 2012 – witnessed seizure, abnormal brain imaging

• McCoy 2011 - epilepsy, witnessed seizure, acute structural brain injury, interictal discharges on EEG

• IPHKL – witnessed seizure

HSV encephalitis

Non-convulsive status epilepticus (NCSE)

a state of ongoing (or non-recovery between) seizures without convulsions, usually for more

than 30 min

Intensive care setting

‘comatose’, ‘encephalopathic’ post convulsive status

Out-patient, epilepsy setting

‘not quite right’, neuroregression

Case example 2

• 10 yr old boy

• Fever provoked convulsions at 7 years

• Unprovoked nocturnal seizures from 8 years, EEG showed GSW, started on Epilim

• Old brother with GTCs, on Epilim

• Now presenting with abnormal behaviour, less responsive, drooling

3 Hz spike waves during spells

Absence SE, underlying idiopathic generalised epilepsy

Case example 3

• 10 yr old boy, underlying mild developmental delay

• Infrequent nocturnal seizures from 4 years, EEG showed centrotemporal spikes, treated as BRE

• From 6 years – had more seizures, unsteady gait, cognitive regression

• EEG encephalopathic, unchanged despite treatment

EEG awake

EEG sleep

BRE with atypical evolution to Electrical Status Epilepticus or Continuous Spikes and Waves during

Slow wave sleep (ESES or CSWS)

language delay/regression no / rare seizures

frequent, bisynchronous CTS

language delay / regression oromotor problems / ataxia

many + & - rolandic seizures frequent, bisynchronous CTS

severe global delay / regression motor and behavioural deficits many rolandic & other seizures

continuous CTS

seizures

development normal

ESES CSWS

delayed development

no or rare seizures

“normal” child no seizures

uni or independent CTS normal (2%)

“normal” child rare rolandic seizures

uni or independent CTS

BRE

Atypical BRE

LKS

Other examples of epilepsies with frequent occurences of NCSE

Syndrome Etiology or clinical context

Clinical form EEG

Benign occipital epilepsy

Idiopathic Autonomic status epilepticus

Occipital ictal rhythms

NCSE in Lennox-Gastaut syndrome

Various, often cryptogenic

Atypical absence status epilepticus

2-2.5 Hz GSW

NCSE in other syndromes (eg ring chromosome 20, Angelman, myoclonic–astatic epilepsy)

Various, usually genetic or cryptogenic

Atypical absence and other nonspecific forms

Various

Non-convulsive status epilepticus

(NCSE)

When to suspect

Intensive care setting

Suspect in ‘comatose’ & ‘encephalopathic’ patients,

especially following witnessed seizures & when imaging is

abnormal

Out-patient, epilepsy setting

Suspect in certain epilepsy syndromes when patient is ‘not

quite right’ or shows neuroregression

Do NCS/NCSE in ICU cause any harm?

Midline shift after intracranial haemorrhage

Vespa 2003 Presented by Hirsch, AES meeting 2010

NCS in TBI: effect on ICP

Vespa 2007 Presented by Hirsch, AES meeting 2010

Presence of NCS/NCSE is an independent predictor of worse outcome

De Lorenzo 1998

Variable Mortality OR (95% CI)

p-value Worsened PCPC OR (95% CI)

p-value

Seizure Category

No Seizures

Ref Ref Ref Ref

Electrographic Seizures

1.3 (0.3, 5.1) 0.74 1.2 (0.4, 3.9) 0.77

Electrographic Status

5.1 (1.4, 18) 0.01 17.3 (3.7, 80) <0.001

Presence of NCSE but not NCS is associated with worse outcome

Topjian 2013

Treatment of NCS/ NCSE

• Same AEDs as for convulsive status

• Balance between side effects and benefits

Do NCS/NCSE in outpatient setting cause any harm?

Neurospychiatric evolution of patients with ESES

typ

ical

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tive

Bra

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sio

ns

Mo

tor

man

ife

stat

ion

s

Pera 2013

Preferred drugs for treatment of CSWS

RCH/ IPHKL

Valproate

Benzodiazepine

Ethosuximide

Sulthiame

Steroids

IVIG

N=196 N=187

Fernandez 2014

Conclusion

• NCSE is an important cause of encephalopathy in the ICU setting, especially in patients with witnessed seizures and abnormal brain imaging

• NCSE may complicate certain epilepsy syndromes, anticipating such complication will assist early detection and effective treatment

• Successful treatment of NCSE may impact positively on mortality and long term neurodevelopmental outcome

Electrical (non-convulsive) status epilepticus

Thank you

Acknowledgment

Dr Khoo

IPHKL EEG unit

IPHKL Paed Neuro team

Patients and families