Volume 11 Issue 1 (February) - Australasian Society for Ultrasound ...

Jaqueline Cartmill, Ann Quinton, Michael Peek
Fig. 10: Axial prenatal MRI demonstrating unilateral left 'porencephalic
cyst'.
Fig. 12: Sagittal prenatal MRI demonstrating preserved antero-medial
left frontal lobe.
Fig. 11: Coronal prenatal MRI demonstrating mild ventriculomegaly
negative PCR for CMV and toxoplasmosis. Fetal MRI
reported a unilateral left porencephalic cyst, consistent
with intrauterine ischaemic insult and resultant infarction
in the left middle cerebral artery territory. There was
ventriculomegaly of the normally formed right cerebral
hemisphere, which was felt to be most likely secondary
to some degree of global ischaemia (Figs 10, 11, 12).
Following consultation with a paediatric neurologist, it
was felt that the most likely outcome would consist of
contralateral weakness and sensory loss, with mild to
moderate intellectual impairment, the severity of which
was difficult to estimate. Multidisciplinary discussion
was undertaken with the patient and she elected to continue
with the pregnancy. Regular two weekly scans were
performed throughout the remainder of the pregnancy
and did not demonstrate any significant changes in the
appearance of intracranial structures. The patient developed
preeclampsia at 37 weeks 5 days gestation and a
live male infant was delivered by emergency caesarean
section, weighing 3180 g with Apgars of 4 at one minute
and 7 at five minutes.
On initial neurologic examination, there was mild hypotonia
in all limbs with normal reflexes. Intermittent orogastric
tube feeds were required at first, however, sucking gradually
improved and full breast feeds were achieved on day nine.
Genetic consultation noted a few dysmorphic features (large
mouth, broad nasal bridge, small upturned nose and hypertelorism).
A repeat karyotype was normal. Eye check showed
bilaterally small optic discs with normal retinas.
Postnatal MRI of the baby, performed at seven days,
demonstrated a large left sided cystic space lined by grey
matter and an absent septum pellucidum, consistent with a
large open-lip schizencephaly. There was also a lipoma adjacent
to the right caudate head. There was no evidence of any
structural abnormality on the right side and the remaining
brain parenchyma was normal. The overall appearance was
felt to be most likely due to an early vascular insult in the left
middle cerebral artery territory (Figs 13, 14, 15).
The infant was discharged on day 11 of life, and follow
up was arranged with a paediatric neurologist, an ophthalmologist
and genetic services.
Case 3 – Intracranial haemorrhage
A 31-year-old woman, in her second pregnancy, presented at
29 weeks 4 days gestation with upper abdominal pain. The
pregnancy had otherwise been uneventful. An abdominal
ultrasound was performed, and as an incidental finding, fetal
intracranial anatomy appeared to be abnormal with head
measurements significantly increased.
Ultrasound in our unit at 30 weeks 1 day gestation
demonstrated features highly suggestive of fetal intracranial
haemorrhage (Figs 16, 17), with a markedly enlarged head
size above the 95th centile (biparietal diameter of 115.5
mm and head circumference of 413.5 mm). Liquor volume
was also increased (amniotic fluid index of 29.6 cm with
maximum vertical pool of 12.3 cm), which was postulated
to be the reason for the initial presentation with abdominal
discomfort. Fetal intracranial anatomy was extremely difficult
to visualise adequately.
Blood was sent for investigation of feto-maternal alloimmune
thrombocytopenia (FMAIT), CMV and toxoplasmosis
serology and thrombophilia screen, all of which were negative.
In view of the polyhydramnios, the patient was commenced
on oral sulindac 200 mg TDS. Amniocentesis was
2 ASUM Ultrasound Bulletin 2008 February 11 (1)