Pediatric Neurologic Emergencies

transcript

Leybie AngJuly 31 2008

Objectives

Febrile Seizures

Status Epilepticus

Encephalitis

FEBRILE SEIZURE

Case Presentation

16 month old, former 38 weekerPreviously healthyBrought in by EMSSeizure activity at homeLasting 1-2 minutesArms and legs twitching3 days hx of URI symptoms

Febrile Seizure – Definition

NIH definition An event in infancy or childhood usually

occurring between 3 month and 5 year of age, associated with fever but without evidence of intracranial infection or defined cause of seizure

Febrile Seizure - Incidence

2-5% in children < 5yo Up to 15%

Majority between 12-18mo One parent – 4.4xBoth parents – 20xSibling – 3.6 x Second degree relative – 2.7x

Simple Febrile Seizure

Most commonSeizure < 15 minutesNo focal featuresOnly once in 24hr time period

Complex Febrile Seizure

Episodes lasting > 15 minutesFocal features or postical paresis> 1 episode in 24 hrsSeizure in a series with total duration >

30minutes

Risk Factors For Recurrence

Low fever at time of first sz (<40)Young age (<12 month old)Family hx of febrile szShort period of time between fever and sz

(<24hr)?male

Risk Factors For Developing Epilepsy

Family Hx of epilepsyComplex featuresPresence of early onset

neurodevelopmental abnormalies

Febrile Seizure - Immunization

Risk of febrile seizure increasesBy 1.5 fold on day of DTP immunization

Risk now reduced if DTaP Acellular pertussis instead of whole cell

pertussisBy 3.0 fold with the peak occurring 1-2

weeks after MMR vaccination

Differential Diagnosis

Shaking/ChillsTraumaToxinsMetabolic disorderMeningitis/Encephalitis

Febrile Seizure - Management

AntipyreticsSponging Antiepileptic

Febrile Seizures – Antipyretics

Uhari et al J peds 1995 126:991 180 kids RDBPC (plac + plac, plac + acet, diaz + acet, diaz + plac) no difference in recurrence x2yrs

Schnaiderman et al Eur J Peds 1993 152:747 104 kids RCT acet q4h scheduled or prn, no difference

Van Stuijvenberg et al Peds 1998 102:1 230 kids RDBPC ibuprofen to plac no diff X1yr

Febrile Seizure - Antipyretics

Meremikwa et al Cochrane Database 2002 Systematic review of 12 trials acetaminophen

vs placebo +/-sponging

Insufficient evidence

Febrile Seizure - Diazepam

Dose given when: when child is febrile before start seizing or as soon as start seizing

Oral dosage given at time of fever – 44% reduction in the risk of febrile seizure per person-year with diazepam

Febrile Seizure - Phenobarbital

Effective in preventing recurrence of simple febrile seizure

Daily therapy reduced the rate of subsequent febrile seizure from 25% to 5%

Adverse effect : hyperactivity, hypersensitivity reaction (SJS), loss of

cognitive function

Febrile Seizure – Valproic Acid

As effective as phenobarbital in preventing recurrent simple febrile seizure

More effective than placebo

Side effect : Fatal hepatotoxicity (esp <3yo at greatest risk)

Febrile Seizure - Prevention

Committee on Quality Improvement Subcommitteeon Febrile Seizure of the AAP 1999 “Based on the risk and benefits of effective

therapies, neither continuous nor intermittent anticonvulsant therapy is recommended for children with one or more simple febrile seizures. AAP recognises that recurrent episodes of febrile seizures can create anxiety in some parents and their children and as such appropriate educational and emotional support should be provided”

Question #1

In the emergency department, you are talking with the parents of a 17 month old boy who was evaluated for a first generalised seizure that lasted 7 minutes and followed by a fever 102.9 F (39.4 C). Other than OM, findings on the physical examination were normal, and the child was discharged home. The child is developmentally normal. Upon examination, the child now appears well.

Of the following, your MOST likely statement to the parents is that

A. antipyretic agents are effective in preventing future febrile seizures

B. CT head is preferred to MRI brain for evaluation of this child

C. EEG is not indicated D. The chance of another febrile sz is ~50% E. The child has a 5% chance of developing

epilepsy

STATUS EPILEPTICUS

Status Epilepticus - Introduction

EFA Two or more sequential seizures without full

recovery of consciousness between seizures, or more than 30 minutes of continuous seizure activity

10-58 per 100,000 per year for children 1 to 19 year old

More common in in children with epilepsy 9-27%

Status Epilepticus - Etiology

26% acute CNS insult Bleed Trauma Infection

20% underlying seizure disorder Sudden discontinuation of meds Drug interaction Fever

53% unknown

Status Epilepticus

Status Epilepticus – Blood Culture

Should blood culture be routinely done in children in SE?

Six Class III studies, total 357 children, BC positive in 2.5%

Insufficient data to support or refute in children whether blood cultures should be done routine basis in children whom there is no clinical suspicious for infection

Status Epilepticus – Lumbar Puncture

Should LP be routinely done in children with SE?

Class III studies – out of 1,859 children 12.8% has documented CNS infection

Insufficient data to support or refute in children whether lumbar puncture should be done routine basis in children whom there is no clinical suspicious for infection

Status Epilepticus – AED Levels

Should AED levels be routinely obtained in children taking AED who develop SE?

Class II data showed that low AED levels in 32% of children on AEDs

AED levels should be considered when a child with epilepsy on AED prophylaxis develops SE

Status Epilepticus – Toxicology Testing

Should toxicology testing be routinely ordered in children with SE?

Class III studies showed that a diagnosis of ingestion in 3.6%

Toxicology testing maybe considered in children with SE, when no apparent etiology is immediately identified.

Specific serum toxicology level is required

Status Epilepticus - EEG

Should an EEG be routinely performed in the evaluation of a child with SE?

Class III studies reported that abnormal brain activity on 43.1% of EEG done on SE

EEG may be considered in a child with new onset SE

Status Epilepticus – Imaging

Neuroimaging may be considered for the evaluation of the child with SE if there are clinical indications or if the etiology is appropriately stabilised and the seizure activity controlled

Imaging - CT vs. MRI

MRI useful for: More detailed view of brain anatomy Better screen for CNS malformations and

dysplastic lesions, temporal lobe (esp. hippocampus)

CT useful for: Larger neoplasms, old infarctions, major

malformative processes Assessment of the critically ill child

Status Epilepticus - Managemnet

SE treatment

1st line anticonvulsants IV

Lorazepam 0.1mg/kg Diazepam 0.2 mg/kg Midazolam 0.2 mg/kg

Rectal diazepam 2-5 yrs – 0.5 mg/kg 6-11 yrs – 0.3 mg/kg >12 yrs – 0.2 mg/kg

IM, intranasal, buccal midazolam

SE treatment

2nd line agents Phenytoin 20 mg/kg @ 1mg/kg/min (upto 50 mg/min) Fosphenytoin 15-20 PE/kg @ 3 mg/kg/min (upto 150

mg/min)

3rd line agents Phenobarbital 20mg/kg @ 100mg/min Repeat prn 5-10mg/kg Maximum 40 mg/kg or 1 gram

Refractory SE treatment

Consider midazolam 0.2 mg/kg bolus 1-10 mcg/kg/min infusion

Induce barbiturate coma Pentobarbital 5-15 mg/kg @ 25 mg/min Then 1-5 mg/kg/hour

Others Valproic acid Paraldehyde, chloral hydrate Propofol, inhalational anesthesia, paralysis lidocaine

Status Epilepticus - Complications

Hypoxia Impaired ventilation Increased secretions Increased O2 consumption Impaired O2 delivery Metabolic and respiratory acidosis

Brain injury Hypoxia and hypoperfusion MR, behaviour changes, neuro deficits

Status Epilepticus - Complications

Morbidity< 1yo - 30% > 3yo – 6%Mortality

Question #2

A 8 month old girl is brought into the emergency department in status epilepticus. She has had diarrhea for the past 4 days. The infant had received bottled water for the past 3 days of her illness and cola for the past 24hr.

Of the following, the MOST likely cause of her status epilepticus is

A. HypocalcemiaB. HypoglycemiaC. HypokalemiaD. HypomagnesemiaE. Hyponatremia

ENCEPHALITIS

Case Presentation

16 yo old female presents with fever, headache, neck stiffness, swallowing difficulties and altered mental status

Symptoms have worsened over past 2 days.

Roommate noted a change in behaviour for the past week

2 weeks ago had a bad URTI- missed 2 days of school

Encephalitis

Defined as acute CNS dysfunction with radiographic or laboratory evidence of brain inflammation

1. Primary Encephalitis cause bloodstream infection, then enter the CNS

2. Post- or Parainfectious not caused by direct CNS infection consequence of the host’s immune response

Encephalitis

HSV - typically infects neurons in the temporal lobe

Rabies - predominantly affects the pons, medulla, cerebellum, and hippocampus

Japanese encephalitis virus affects the brainstem and basal ganglia.

Post- Parainfectious Encephalitis

occurs days to weeks after the onset of an infection

hypothesized to be caused by an aberrant immune response against brain antigens such as myelin basic protein

Subsequent demyelination causes focal or global CNS dysfunction

Encephalitis - Epidemiology

overall incidence of hospitalization was 7.3 cases/100,000 annually

Children < 1 yo - 13.7 cases/100,000 per yr

Adults >65 yo - 10.6 cases/100,000 per yr

Clinical presentation

Fever HeadacheAltered mental status Focal neurologic signs spectrum of clinical evolution during

encephalitis varies widely

Encephalitis

CT scan – nml at the onset of encephalitis.MRI – much more sensitive for acute

changes

EEG - helpful adjunct +/- localize the region of encephalitic involvement considerably more sensitive

Management

Appropriate antiviral, antimicrobial or antifungal therapies

Intravenous immune globulin, corticosteroids, or other immune system modulators.

Herpes Simplex Virus Encephalitis

Most common encephalitis diagnosedFeverPersonality changeAutonomic dysfunctionDysphagiaSeizuresHeadacheAltered level of consciousness

Mildly elevated CSF WBC counts (lymphocyte predominant) and CSF protein

CT and MRI studies - normal if obtained early in the course of illness Unilateral or bilateral temporal lobe involvement (most common

finding)

Diagnostic test - HSV DNA detection by PCR on the CSF both highly sensitive and specific If initial result negative, test should be repeated on a second

CSF specimen.

Treatment

IV acyclovir 10 mg/kg per dose every 8 hours for 2 to 3 weeks.

Better outcomes if: age < 30 yo shorter duration of symptoms before initiation of

treatment GCS >10 at the time of presentation.

Investigations

CT headLPCBC, Blood cultureLytesGlucoseESR, CRP

Back to our patient

Question #3

For a patient who is suspected of having acute encephalitis, which of the following studies is most likely tobe helpful?

A. Cerebrospinal fluid glucose level.B. Computed tomography scan.C. Electroencephalography.D. Magnetic resonance imaging.E. Viral culture

Any Questions?

References

C Waruiru and R Appleton Febrile seizures: an update Arch Dis Child. 2004 August; 89(8): 751–756.

Jones T. Jacobsen SJ. Childhood febrile seizures: overview and implications International Journal of Medical Sciences. 4(2):110-4, 2007.

Baumann RJ. Duffner PK. Treatment of children with simple febrile seizures: the AAP practice parameter. American Academy of Pediatrics. Pediatric Neurology. 23(1):11-7, 2000 Jul.

AAP Practice Parameter: Long Term Treatment of the Child With Simple Febrile Seizure Pediatrics. 103(6) June 1999

References

Appleton R. Choonara I. Martland T. Phillips B. Scott R. Whitehouse W. The treatment of convulsive status epilepticus in children. Archives of Disease in Childhood. 83(5):415-9, 2000 Nov.

Riviello JJ Jr. Ashwal S. Hirtz D. Glauser T. Ballaban-Gil K. Kelley K. Morton LD. Phillips S. Sloan E. Shinnar S. American Academy of Neurology Subcommittee. Practice Committee of the Child Neurology Society. Practice parameter: diagnostic assessment of the child with status epilepticus Neurology. 67(9):1542-50, 2006 Nov 14.

Pediatric Neurologic Emergencies

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