Radiology
Early Diagnosis of
Harlequin Eye
and Other Craniosynostoses Is Key
By Catherine B. Lerner, M.D.
Working as a team with referring clinicians, pediatric radiologists can
facilitate the early detection of this important pediatric diagnosis.
Clinicians who care for children are often
faced with the task of evaluating an infant for
abnormal skull shape. Most cases of localized
skull flattening are caused by deformational
or positional plagiocephaly, particularly given
the successful implementation of the “backto-sleep” campaign. Although abnormal
skull shape is due to positioning in the
majority of infants, it is sometimes due to
craniosynostosis, or premature fusion of a
cranial suture or sutures. Craniosynostosis
is a serious clinical problem that can
require surgical treatment, so differentiation
between craniosynostosis and positional
plagiocephaly is important.
In general, true craniosynostosis is ten-fold
less common than positional plagiocephaly.
Of the craniosynostoses, most involve just
one suture and are isolated events, rather than
being part of a genetic syndrome. The suture
most frequently involved by craniosynostosis
is the sagittal suture (40 to 60 percent of
cases), followed by the coronal suture (20 to
30 percent of cases). When coronal suture
synostosis is unilateral, the result is one of the
Figure 1. The Harlequin Eye. Skull radiograph in a 2
month-old girl demonstrates findings of unilateral,
right-sided coronal synostosis. These include elevation and posterior displacement of the superior and
lateral orbital rim.
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The Triangle Physician
more recognizable clinical and radiographic
presentations of craniosynostosis, that of the
“harlequin eye” deformity of the orbit. The
“harlequin eye” is meant to describe elevation
of the ipsilateral lesser wing of the sphenoid,
with posterior displacement or retraction of
the superior and lateral rims of that orbit.
A more common, and perhaps more
challenging, clinical scenario is that
of distinguishing between positional
plagiocephaly and the unusual but clinically
important
lambdoid
craniosynostosis.
The evaluation begins with the physical
examination findings, and there are features
here that can help differentiate the two. Both
can cause occipitoparietal flattening, but in
positional plagiocephaly, when examining the
infant from above, one sees frontal bossing
and anterior displacement of the ear on the
same side as the posterior (occipitoparietal)
skull flattening. To the contrary, in the rare
cases of lambdoid synostosis, one may see
frontal and parietal bossing on the opposite
side of the posterior (occipitoparietal)
flattening, and the ear on the side of the
occipitoparietal flattening may be displaced
posteriorly, toward the fusing suture. With
lambdoid synostosis, one may also see a
“mastoid bump” on the same side as the
posterior flattening, as growth can still occur
at the patent posterolateral fontanel.
When a clinician encounters an infant with
abnormal skull shape or facial features
that cannot be attributed to positional
plagiocephaly, referral to a pediatric
radiologist is an important next step. A
radiographic skull series serves as the
appropriate screening study in evaluation
of such infants. The pediatric radiologist
evaluates the radiographs for any signs of
craniosynostosis such as increased sclerosis
at the sutures, narrowing of a suture or
Dr. Catherine
Lerner is a pediatric
radiologist at
Wake Radiology
Pediatric Imaging
Center. A native of
Tallahassee, Fla.,
she received her
medical training at
Columbia University
College of Physicians and Surgeons in New
York and served her internship at St. Vincent’s
Catholic Medical Center there. She completed
a fellowship in pediatric radiology at Duke
University Medical Center, where she was chief
resident in diagnostic radiology. She is a cum
laude graduate of Yale University, where she
earned a bachelor of science degree in biology
and a bachelor of arts degree in art history. She
has authored articles appearing in Pediatric
Radiology and the journal Cancer. Dr. Lerner
is board certified in diagnostic radiology by the
American Board of Radiology, and is a member
of the Radiological Society of North America
and the Society for Pediatric Radiology. She can
be reached at (919) 782-4830.
loss of suture clarity, or frank bony bridging
across a suture. In addition, if performed
at a dedicated pediatric imaging center, the
pediatric radiologist has the opportunity
to examine the patient when indicated. If
an abnormality is detected, a low-dose
head CT that is tailored to the evaluation of
craniosynostosis can be performed. With this
head CT, the infant is assessed for additional
abnormalities that could not be appreciated
on skull radiographs, recognizing that more
than one suture may be affected in a minority
of patients. In addition, using the pediatric
craniosynostosis protocol, three-dimensional
reconstructed images can be rendered
to aid the surgeon in his or her treatment
planning. Working as a team with referring
clinicians, pediatric radiologists can facilitate
the early detection of this important pediatric
diagnosis.
A pediatric radiologist is available for
consultation weekdays from 8am to 5pm at
the Wake Radiology Pediatric Imaging Center,
4301 Lake Boone Trail in Raleigh, (919) 7824830.
References
- Blaser SI Abnormal skull shape. Pediatr Radiol
(2008) 38 (Suppl 3):S488-S496.
- Kabbani H and Raghuveer TS. Craniosynostosis.
Amer Fam Phys (2004) 69 (12): 2863-2870.