International Journal of Clinical Medicine, 2012, 3, 431-432
http://dx.doi.org/10.4236/ijcm.2012.35080 Published Online September 2012 (http://www.SciRP.org/journal/ijcm) 1
Antenatal Son ographic Diagnosis of a Case of Alobar
Holoprosencephaly: A Case Report
Rizwan Ahmad Khan1, Manjari Thapa2, Shagufta Wahab2*
1Division of Pediatric Sugery, Department of Surgery, JN Medical College, Aligarh Muslim University, Aligarh, India; 2Department
of Radiodiagnosis, JN Medical College, Aligarh Muslim University, Aligarh, India.
Received May 2nd, 2012; revised June 6th, 2012; accepted July 19th, 2012
ABSTRACT
Holoprosencephaly is a rare congenital brain malformation resulting from failure of diverticulation and cleavage of
primitive prosencephalon which occurs at 4th - 8th week of gestation and is usually associated with multiple midline
facial anomalies. Herein we report an antenatal case of such patient. Patient was evaluated and because of the magni-
tude of the problem induction was done which led to a still born baby.
Keywords: Holoprosencephaly; Alob ar; Antenatal Detection; Developing Countries; Prognosis
1. Introduction
Holoprosencephaly is a rare congenital brain malforma-
tion resulting fro m failure of diverticulation and cleavage
of primitive prosencephalon which occurs at 4th - 8th
week of gestation and is usually associated with multiple
midline facial anomalies. This disorder is either incom-
patible with life or infants suffer from varying grade of
mental retardation.
Sonography is an excellent non-invasive tool for pre-
natal diagnosis of holoprosencephaly. This case report
describes a case of alobar holoprosencephaly diagnosed
prenatally with ultrasound and highlights the importance
of high-resolution real time imaging. We want to stress
that the conditio n is rare and therefore lack of familiarity
may lead to diagnostic confusion.
2. Case Report
A 24-year-old, gravida 2 and para 1 underwent antenatal
ultrasonography at 24 menstrual weeks as determined by
dates, which disclosed increased intracranial fluid in the
fetus. Past medical history and family history were un-
remarkable, with the previous child being born at term
with no congenital anomaly. A repeat ultrasound exami-
nation demonstrated a monoventricle fluid-filled cavity.
The cerebral cortex was represented by thinned out man-
tle. Two orbits were seen; no clear evidence of proboscis
was seen. The midbrain and posterior fossa appeared
normal (Figures 1). An increased amount of amniotic
fluid (polyhydramnios) was present. Based on the ante-
natal sonographic findings a diagnosis of alobar holo-
prosencephaly was made. Preterm induction of vaginal
delivery resulted in a stillborn fetus. Examination of the
fetus demonstrated only proptosis but no gross facial
anomaly. Brain morphology could not be assessed due to
autolysis. Chromosomal analysis disclosed a trisomy 13
karyotype. Patient was investigated as per the guidelines
set by the Ethics committee of our hospital.
3. Discussion
The incidence of holoprosencephaly is approximately 1 -
1.4 per 10,000 live births [1] but as the incidence of
Figure 1. Antenatal sonogram of fetal head (coronal view)
with alobar holoprosencephaly showing monoventricular
cavity with surrounding thinned cerebral tissue, fused tha-
lami and absence of midline structures such as falx cerebri.
Axial view of the same patient showing fused thalami and
thinned out cortical mantle of the fetal head.
*Corresponding a uthor.

Antenatal Sonographic Diagnosis of a Case of Alobar Holoprosencephaly: A Case Report
432
spontaneous abortions is high, the actual incidence may
be quite high. Both environmental factors and genetics
are suspected in its etiology and approximately 30% of
the cases are associated with chromosomal defects
mostly trisomy 13 and 18. However most of the cases
have a normal karyotype [2]. It represents a spectrum of
disorder with most severe form known as alobar type
showing absolutely no cleavage of prosencephalon with a
large monoventricular system surrounded by a thinned
out mantel with absent falx cerebri, corpus callosum,
fornix, optic tract and olfactory bulbs. The thalami are
fused with absent third ventricle and the single ventricle
usually communicates with a dorsal sac [3]. The infants
are stillborn or survive only upto few d ays or weeks. Se-
milobar holoprosencephaly is an intermediate form with
posterior partial separation of two hemispheres and ven-
tricles thus a rudimentary occipital horn with a small
portion of falx and interhemispheric fissure in the oc-
cipital cortex may be seen. Thalami are partially sepa-
rated with a rudimentary third ventricle [3]. The least
severe form is the lobar variety showing almost complete
separation of cerebral hemispheres and lateral ventricle
with developed falx and interhemispheric fissure so pre-
natal diagnosis may be difficult. Cavum septum pellu-
cidum is however absent and there is fusion of frontal
horns [3]. This syndrome is associated with mild mental
retardation. The mildest form is septo-optic dysplasia
with absent septum pellucidum, optic nerve hypoplasia
and associated hypothalamic-pituitary dysfunction. As
the face develops at the same time as the diverticulation
of brain, holoprosencephaly is accompanied by a number
of midline facial anomalies and the degree of facial dys-
morphism parallels the severity of holoprosencephaly so
sonographic evaluatio n of facial morphology may he lp in
prenatal diagnosis of holoprosencephaly. Studying the
strong association between facial anomalies and holo-
prosencephaly, DeMeyer commented “brain malforma-
tions can be predicted by patient’s face” [4]. The severest
facial malformation like cyclopia, ethmocephaly and ce-
bocephaly occurred only with alobar holoprosencephaly
[5] with semilobar and lobar types showing milder facial
anomalies .These are hypotelorism, median cleft lip and
palate, lateral cleft lip and palate and pyriform aperture
stenosis [5-7]. However the face may even be almost
normal in few cases of alobar holoprosencephaly as in
our case. Other extrafacial anomalies are also common
with holoprosencephaly and includes polydactyly, renal
dysplasia, omphalocele, club foot, esophageal atresia,
cardiac malformation etc. [4,5]. Routine obstetric USG is
performed during the first trimester preferably between
11th - 14th week of gestation and besides determining
the gestational age, number of foetuses and presence of
any complication, USG can also detect a number of con-
genital ano malies. Sonography is most helpful in th e pre-
natal diagnosis of holoprosencephaly especially of alobar
type and is the decisive modality for the management and
follow-up of such cases so that the mother can opt for
termination of pregnancy and the doctor can decide for a
vaginal delivery rather than caesarean section [8-10].
4. Conclusion
Although rare, facial and brain anomalies can be recog-
nized in high resolution ultrasonography probe is used.
Interorbital spaces, ventricular configuration and facial
morphology should be looked for in both the planes.
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