A Growing Skull Fracture
Radiology Cases in Pediatric Emergency Medicine
Volume 7, Case 2
Rachel O. Newton-Weaver, MD
Kapiolani Medical Center For Women And Children
University of Hawaii John A. Burns School of Medicine
This is a 10-month-old male who sustained an
unwitnessed fall off a patio deck. The height of the fall
was estimated at 2-3 meters. He landed on a concrete
surface. Relatives were nearby and immediately ran to
the screaming child. There was no reported vomiting or
seizure activity.
On physical examination he was noted to be sleepy
but easily arousable. There was echymosis and an
abrasion over the right periorbital area. A 7 by 4 by 1
cm hematoma was palpated over the right parietal
region. No Battle's sign was present. His pupils were
equal and reactive to light and extraocular movements
were intact. Tympanic membranes were intact without
hemotympanum. He had no areas of tenderness,
swelling, bruising or deformity over his trunk and
extremities.
A CT scan of his head was performed.
View his CT scan.
This CT scan shows an elevated right parietal skull
fracture with a floating fracture fragment, subarachnoid
hemorrhage, hemorrhagic contusion of the right parietal
and occipital lobes and a right parietal subdural
hematoma. He was hospitalized and treated
conservatively with a good recovery.
Three months after the fall he is now noted to have
a palpable right parietal skull fracture defect with a 1
cm "gap" in the bone. No palpable, pulsatile masses
are noted. On clinical exam, he does not have any
neurologic defects. A skull series is ordered.
View his skull films.
These are his left and right lateral views of his skull
which show a large "gap" with smooth edges consistent
with a growing skull fracture over his right parietal skull
region. A follow up CT scan of his head is ordered.
View his follow up CT scan.
These CT scan images demonstrate the persisting
skull defect and an underlying encephalomalacic cystic
defect which is consistent with a leptomeningeal cyst.
He underwent a right craniotomy with dural repair.
Discussion
Simple skull fractures usually heal without incident
within a few weeks. One potential complication is a
"growing skull fracture". Although most commonly
known as a growing skull fracture, it is also referred to
as a leptomeningeal cyst or posttraumatic meningocele
(1). The essential features of this condition are a skull
fracture in infancy or early childhood, a dural tear at the
time of fracture, brain injury beneath the fracture and
subsequent enlargement of the fracture to form a
cranial defect (2).
The incidence of growing skull fractures is estimated
at 1% among skull fractures in children. Growing skull
fractures occur during the first 3 years of life and almost
never after eight years of life (3). This is due to the
rapid increases in brain growth seen only in infancy.
Pathogenesis
A dural laceration is an essential component of a
growing skull fracture. The development of a growing
skull fracture requires a fracture severe enough to
include a tear in the underlying dura and an outward
driving force such as a normally growing brain or
hydrocephalus (1). Continued pulsation of the brain
and arachnoid is thought to enlarge the fracture over
time (4) and herniation of the cerebral tissue or
subarachnoid fluid through the fracture line may occur.
A leptomeningeal cyst represents an invagination and
entrapment of arachnoid into a diastatic fracture with an
associated dural tear (5). This prevents healing of the
fracture margins, can cause expansion of the fracture
and is a palpable mass on physical exam.
Linear fractures most commonly are associated with
growing skull fractures while depressed fractures are
not. A fracture with a diastasis (separation) of more
than 4 mm may be considered at risk of developing a
growing fracture (3). Beneath the lesions of skull and
dura matter there is local brain injury which is a
constant feature of this syndrome (2) and on acute
imaging studies there is usually an indication of a
cortical injury immediately beneath the fracture (1).
A growing skull fracture presents as a progressively
enlarging pulsatile mass or an enlarging and sunken
palpable cranial defect (6). It may enlarge over
months and occur months after the initial skull fracture.
Neurological complications related to growing skull
fractures include seizures (often intractable),
hemiparesis and psychomotor retardation (3). The
majority of cases have shown progressively worsening
neurologic deficits over time (6). Therefore, it is
important to examine children with skull fractures 4-6
weeks post injury to ensure adequate healing at the
site of the initial fracture.
The most common location for the development of a
growing fracture is the parietal bone, although it can
occur anywhere, including the skull base (1). Skull
radiographs taken at the time of the initial injury will
universally demonstrate a diastatic fracture, with the
edges separated by more than 3mm (6).
Computed tomography is helpful in identifying
underlying intracranial pathology. Imaging done at the
time of trauma may show a hemorrhagic contusion or
subarachnoid or extraparenchymal hemorrhage (3).
CT scan done months after the injury may also
demonstrate unilateral ventricular enlargement and a
shift toward the skull defect (6).
Early surgical correction is recommended due to the
risk of neurological complications (seizures,
hemiparesis). There is no indication that the condition
ever improves spontaneously (6). Intractable seizures
in association with a growing skull fracture often
respond to surgical correction. Principles of surgery
include reconstruction of the dura, reconstruction of the
skull and excision of excessive scalp tissue (4).
References:
1. Luerssen TG. Skull fractures after closed head
injury. In: Albright AL, Pollack IF, Adelson PD (eds).
Principles and Practice of Pediatric Neurosurgery.
Thieme, New York, 1999, pp821-823.
2. Lende RA, Erickson TC. Growing skull fractures
of childhood. Journal of Neurosurgery
1961;18:479-487.
3. Tomita T. Growing skull fractures of childhood.
In: Wilkins RH, Rengachary SS (eds). Neurosurgery.
McGraw Hill, New York, 1996, pp2757-2761.
4. Raffel L, Litofsky NS. Skull fractures. In: Cheek
WR (ed). Pediatric Neurosurgery. WB Saunders
Company, Philadelphia, 1994, p258.
5. Beckett WW, Ball WS. Craniocerebral trauma.
In: Ball WS (ed). Pediatric Neuroradiology.
Lippincott-Raven, Philadelphia, 1997, pp454-455.
6. Luerssen TG, Eisenberg HM, Levin HS. Late
complications of head injury. In: Cheek WR (ed).
Pediatric Neurosurgery. WB Saunders Company,
Philadelphia, 1994, pp297-298.
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