ultrasound diagnosis of fatal anomalies

THE CENTRAL NERVOUS SYSTEM AND THE EYE
Hydranencephaly
Definition: Extreme form of porencephaly
where the cerebral cortex is either absent or only
minimally preserved. Besides, severe hydrocephalus
is present.
Incidence: Rare.
filled cavity ex vacuo). Termination of pregnancy
is justified due to the unfavorable prognosis.
Prognosis: Fatal. Very few survive with severe
mental retardation. Some may survive the immediate
neonatal period.
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Sex ratio: M:F=1:1.
Clinical history/genetics: Sporadic, occasionally
familial inheritance. Described in over 20 syndromes.
Teratogens: Congenital infections, cocaine.
Embryology : Destruction of the cerebral tissue
due to vascular occlusion or infection. Possibly
resulting from an early stenosis of both internal
carotid arteries. Hydrocephalus ex vacuo.
Associated malformations: None.
Fig. 2.31 Hydranencephaly. 30 + 5 weeks. Severe
dilation of the lateral ventricles. The rim of cortex
measures 3 mm.
Ultrasound findings: There is practically no evidence
of cerebral tissue above the brain stem and
diencephalon. Even the falx cerebri is mostly absent.
Infarction of the brain tissue may occur in
the later part of pregnancy (30 weeks).
Clinical management: Karyotyping and search
for infections (TORCH). The accompanying hydrocephalus
does not progressively enlarge, as
opposed to obstructive hydrocephalus (fluid-
References
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Belfar HL, Kuller JA, Hill LM, Kislak S. Evolving fetal hydranencephaly
mimicking intracranial neoplasm. J
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Castro-Gago M, Pintos-Martinez E, Forteza-Vila J, et al.
Congenital hydranencephalic–hydrocephalic syndrome
with proliferative vasculopathy: a possible relation
with mitochondrial dysfunction. J Child Neurol
2001; 16: 858–62.
Witters I, Moerman P, Devriendt K, et al. Two siblings
with early-onset fetal akinesia deformation sequence
and hydranencephaly: further evidence for autosomal-recessive
inheritance of hydranencephaly,
Fowler type. Am J Med Genet 2002; 108: 41–4.
Hadi HA, Mashini IS, Devoe LD, Holzman GB, Fadel HE.
Ultrasonographic prenatal diagnosis of hydranencephaly:
a case report. J Reprod Med 1986; 31: 254–
6.
Lam YH, Tang MH. Serial sonographic features of a fetus
with hydranencephaly from 11 weeks to term. Ultrasound
Obstet Gynecol 2000; 16: 77–9.
McGahan JP, Ellis W, Lindfors KK, Lee BC, Arnold JP. Congenital
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abnormalities: a sonographic classification. JCU J
Clin Ultrasound 1988; 16: 531–44.
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