​To Tap or Not to Tap, That is the Question: At Least When it comes to Complex Febrile Seizure

 
CC: Seizure
 
HPI: This is a fully vaccinated 18 month female here after seizure activity at home.  Mom states she has had three episodes of generalized tonic-clonic activity in the last 12 hours.  After her first episode, mom states her temperature was 103.4F and has improved with anti-pyretics but returns and she has had two additional episodes of tonic-clonic movement.  Both upper and lower extremities are involved equally and the episode lasts for 60-90 seconds with spontaneous resolution.  She has been sleepy afterwards and then acts more normal but is fussier than usual if the fever doesn’t come down.  Her last episode was 1 hour ago.  She has had no recent trauma, no focal abnormalities, and has otherwise been acting normal until today.  She last received acetaminophen 2 hours ago.
 
Physical Exam:
T 99F P 130 RR 25 O2 100%
Gen:  Is sitting in mom’s lap watching her iphone.  NAD, though she is fussy when you examine her ears, she is appropriately consolable by mom afterwards
HEENT:  Bilateral TMs normal without erythema or bulge, oropharynx is normal without lesions or erythema, tonsils are normal in appearance without exudate, copious mucoid drainage from nose
Neck: Moving in all directions
CV: S1S2, RRR, no murmurs, gallops, or rubs
Lung: Transmitted upper airway sounds but no wheezes or rales, no focal lung findings
Abdomen: soft, non-tender, non-distended, no HSM, normal bowel sounds
Musculoskeletal: No focal tenderness in extremities
Lymph: mild cervical lymphadenopathy
Neurologic: Appropriately consolable, acting at baseline per mom now, walking normal, moves all extremities appropriately with normal muscle tone, no altered mental status, smiles at you before you attempt to exam
 
Discussion:
This is a difficult case that we have all likely seen or will definitely see sometime (likely multiple times) in our career.  I have intentionally left out the work-up and management of this case because that is what I want to discuss.  This is a typically appearing 18 month old with a fever.  She is fussy with examination but appropriately consolable by mom like many of our children with viral infections.  The difference here is she has had what appears to be complex febrile seizures (three seizures within 24 hours) but is now back at baseline and didn’t appear to have a prolonged post-ictal period.  She is fully vaccinated but this is still a presentation that should concern all of us.
            So what do you do?  We are emergency medicine physicians and we are trained to worry about bad things.  The biggest thing on all of our minds should be: “do I need to worry about meningitis in this girl (or other pathology but we are focusing on meningitis for this discussion)?”  Unfortunately, there are no consensus guidelines to make our job easy with this one. 
            Let’s cover the low-hanging fruit first.  If this child was still post-ictal, not acting herself per mom, required intubation, required multiple AEDs to stop seizure (i.e. febrile status epilepticus), or had abnormalities on her exam now, she’d get a full septic work-up, antibiotics, and admission along with possible imaging.  This case isn’t that easy though.
            Febrile seizures affect 2-5% of children aged 6 months – 6 years.  25-30% of these febrile seizures may be classified as a complex febrile seizure.  There is also considerable variation within what classifies a child as having had a complex febrile seizure.  The child who had two very brief simple appearing febrile seizures within the same 24hr time period is different than the child with prolonged seizure who has failed to return to baseline.  Often times, clinical judgment and personal experience comes into play with these variable presentations since there are no consensus guidelines for management. 
            Despite this variable presentation, our job is to think about bad things.  The bad thing we are concerned about with this child is acute bacterial meningitis.  There is decreasing prevalence of bacterial meningitis but it hasn’t been eliminated.  There are small studies looking at this exact question and most say the same thing, “routine CSF testing is likely not necessary in an otherwise well appearing child without any abnormalities back at baseline but absolutely necessary if additional findings on exam, incomplete antibiotic administration, or unvaccinated.”  Najaf-Zadeh et al performed a systematic review and meta-analysis in 2013 found the pooled prevalence of ABM in children with complex febrile seizures to be 0.6% (95% CI 0.2-1.4) but this was derived from only two studies.  The overall prevalence of bacterial meningitis in children who had a seizure and fever was frighteningly 2.6% (95% CI 0.9-5.1).
 
Studies evaluating for acute bacterial meningitis with complex febrile seizure

Green et al 1993                

111 children with ABM and seizure
103 comatose or obtunded at presentation
Remaining 8 had abnormal neuro exam or nuchal rigidity
 

Kimia et al 2010

526 children
3 with ABM
Two children with ABM had AMS at presentation
One had contaminated CSF Cx but grew strep in blood

Teach and Geil 1999

243 children
11% with complex febrile seizures
None had ABM
 

Setz et al 2009

390 children
6 with ABM
1 with HSV encephalitis (0.3%)
All had AMS on presentation

Casasoprana et al 2013

157 children
3 ABM but all with complex febrile seizure
Incidence of ABM 1.9%
Additional clinical symptoms strongly associated with ABM

Fletcher and Sharieff 2013

193 patients
1 with ABM (0.5%)
None of the 43 children with two brief febrile seizures had ABM
 

Hardasmalani and Saber 2012

71 Children
1 with ABM
That patient had febrile status epilepticus
 

 
 
So I ask you again, would you perform a lumbar puncture in this child?
 
My personal opinion (and I highly recommend and expect deviation from this):
I do not believe I would perform a lumbar puncture in this child but I wouldn’t discharge her home despite appearing well.  She is normal appearing on examination now and despite the studies being small and underpowered to really answer the question, most are consistent that children with complex febrile seizure who ultimately have ABM have additional clinical findings (large caveat for this patient is that she is fully vaccinated).  Obviously I would not start antibiotics on this patient but I am completely uncomfortable with the thought of discharging her home with complex febrile seizures nor am I a fan of performing a lumbar puncture and discharging home if the cell count is reassuring (culture is my gold standard and I’m sticking to it).  If I had hesitated for one second and felt this child just wasn’t acting right to me or if the mom was insistent that she wasn’t right to her, I’d err on the side of lumbar puncture and treatment.    
 
Interestingly, a survey of 353 pediatric emergency medicine physicians and fellows in 10 US hospitals showed only 34% would perform a lumbar puncture in a child with complex febrile seizure.  That is significantly lower than expected.
                 
 
By Jeremiah Smith, MD
 
References:
Casasoprana A, Hachon Le Camus C, Claudet I, et al.  Value of Lumbar Puncture after a First Febrile Seizure in Children Aged Less than 18 months.  A Retrospective Study of 157 Cases.  Arch Pediatr 2013;20:594-600
 
Fletcher E, Sharieff G.  Necessity of Lumbar Puncture in Patients Presenting with New Onset Complex Febrile Seizures.  West Journ of Emerg Med 2013;14:206-211
 
Green S, Rothrock S, Clem K, et al.  Can Seizures be the Sole Manifestations of Meningitis in Febrile Children.  Pediatrics 1993;92:527-534
 
Hardasmalani M, Saber M.  Yield of Diagnostic Studies in Children Presenting with Complex Febrile Seizures.  Pediatr Emerg Care 2012;28:789-791
 
Hofert S, Burke M.  Nothing is Simple About a Complex Febrile Seizure: Looking Beyond Fever as a Cause of Seizures in Children.  Hosp Pediatr 2014;4:181-187
 
Kimia A, Ben-Joseph E, Rudloe T, et al.  Yield of Lumbar Puncture Among Children Who Present With Their First Complex Febrile Seizure.  Pediatrics 2010;126:62-69
 
Kowalsky R, Jaffe D.  Bacterial Meningitis Post-PCV7: Declining Incidence and Treatment.  Pediatr Emer Care 2013;29:758-769
 
Najaf-Zadeh A, Dubos F, Hue V, et al.  Risk of Bacterial Meningitis in Young Children with a First Seizure in the Context of Fever: A Systematic Review and Meta-Analysis.  PLOSOne 2013;8:e55270
 
Seltz L, Cohen E, Weinstein M.  Risk of Bacterial or Herpes Simplex Virus Meningitis/Encephalitis in Children with Complex Febrile Seizures.  Pediatr Emerg Care 2009;25:494-497
 
Teach S, Geil P.  Incidence of Bactermia, Urinary Tract Infections, and Unsuspected Bacterial Meningitis in Children with Febrile Seizures.  Pediatr Emerg Care 1999;15:9-12