Toxic Infant with a Full Fontanelle.
Radiology Cases in Pediatric Emergency Medicine
Volume 1, Case 1
Loren G. Yamamoto, MD, MPH
Kapiolani Medical Center For Women And Children
University of Hawaii John A. Burns School of Medicine
This is a 5-month old male with fever, irritability, and
vomiting. His temperature at home was 38.0 rectally.
He vomited five times since onset 8 hours ago. He is
feeding soy formula. Past medical history is
unremarkable.
Exam: VS T38.0R, P150, R40 (crying), BP
unobtainable, wt 50%ile. Fussy, though consolable at
times. He doesn't focus or interact well and appears
somewhat "toxic" to the examiner. Anterior fontanelle is
somewhat full, but he is crying so it is difficult to truly
assess. Eyes moist. Pupils reactive. TM's are shiny
and slightly red. Oral mucosa moist. Neck is hard to
assess due to crying. Heart regular without murmur.
Lungs clear. Abdomen soft on inspiration. No
detectable tenderness evident. No hernias. Testes not
swollen. CVA tenderness is not apparent. Color
slightly pale. Capillary refill time 2-3 seconds. Muscle
tone good.
A lumbar puncture is done to rule out meningitis.
The CSF is homogeneously bloody (blood mixed with
CSF). The blood does not clear. All three tubes
appear to be equally bloody. A CBC, blood culture, and
catheterized urine sample are sent to the lab. An IV is
started and the child is given 50mg/kg of cefotaxime IV.
A CT scan is done to rule out subarachnoid
hemorrhage.
View CT scan image.
This CT scan was done without IV contrast. It was
read as a posterior inter-hemispheric subdural
hematoma. It shows blood in the subdural space and
an increased density (whiter than it should be) of the
posterior falx secondary to a posterior inter-hemispheric
subdural hematoma. Other clinical findings and a social
investigation confirmed the etiology as shaken baby
syndrome.
Teaching Points:
1. Although the falx may enhance with IV contrast,
an increased density of the posterior falx before IV
contrast is administered should raise the suspicion of a
posterior interhemispheric subdural hematoma. This
injury is highly indicative of a shaken baby. Other
findings such as retinal hemorrhages and a suspicious
history add to the strength of this etiology.
2. An experienced physician who has done many
lumbar punctures in infants usually knows when to
expect bloody CSF due to the difficulty of the
procedure. If bloody CSF is unexpectedly encountered,
and it does not clear, one should be highly suspicious of
intracerebral hemorrhage with blood entering the
subarachnoid space.
3. Although blood should not appear in the CSF if
the hemorrhage is purely subdural, this injury is not
purely subdural in nature. Blood also enters the
subarachnoid space. Axonal shearing and
generalized cerebral cellular injury take place as well.
4. A full fontanelle is not always indicative of
meningitis. Intracerebral hemorrhage, cerebral edema,
and acute hydrocephalus can all mimic the same
clinical features.
5. Trauma specialists have often taught that
intracranial hemorrhage alone cannot account for all
the blood loss in a patient in hypovolemic shock. In
other words, if you have diagnosed an intracerebral
hemorrhage in a trauma patient in hypovolemic shock,
you must look elsewhere for additional hemorrhaging
sites, such as in the abdomen. Infants appear to violate
this rule since many shaken babies present to the
emergency department in shock. Although one must
always be suspicious of other hemorrhaging sites from
injuries such as from fractures and internal injuries,
subsequent work-ups on these patients may fail to
identify significant hemorrhaging sites other than in the
brain.
6. CT scans may fail to show a posterior
inter-hemispheric subdural hematoma if it is small. MRI
scanning has been shown to be more sensitive at
identifying these hemorrhages and other brain injuries.
References:
1. Ludwig S. Child Abuse. In: Fleisher GR, Ludwig
S, eds. Textbook of Pediatric Emergency Medicine,
third edition. Baltimore, MD, Williams and Wilkins,
1993, p. 1437.
2. Bogost GA, Crues JV, Moser FG. MR Imaging
in the Evaluation of Trauma. Emergency Radiology
1994;1(1):1-14.
3. Sklar EM, Quencer RM, Bowen BC, Altman N,
Villanueva PA. Magnetic resonance applications in
cerebral injury. Radiology Clinics of North America
1992;30(2):353-366.
4. Barkovich AJ. Chapter 4 - Destructive Brain
Disorders of Childhood. In: Pediatric Neuroimaging,
second edition. New York, Raven Press, 1995, pp.
167-170.
Return to Radiology Cases In Ped Emerg Med Case Selection Page
Return to Univ. Hawaii Dept. Pediatrics Home Page