First trimester screening for holoprosencephaly with choroid plexus morphology ('butterfly' sign) and biparietal diameter.

OBJECTIVE: The aim of this study was to determine whether choroid plexus morphology ('butterfly' sign) and biparietal diameter (BPD) are effective sonographic screening tools for holoprosencephaly (HPE) in the first trimester. METHODS: An axial view of the fetal head was obtained routinely to determine the presence of the 'butterfly' sign in pregnancies presenting for sonographic screening at 11-13 weeks of gestation. The same view was also used to obtain BPD measurements. The definitive diagnosis of HPE was established by the sonographic demonstration of an anterior cerebral monoventricular cavity and thalamic fusion. RESULTS: During a 9-year study period, 11 068 live fetuses were screened. There were 11 cases of HPE (prevalence 1/1006); all of them were detected by demonstration of an absent 'butterfly' sign with no false-positive cases. The BPD was less than the 5th percentile in 40% of the cases. CONCLUSIONS: The 'butterfly' sign appears to be a highly sensitive marker for HPE in the first trimester. On the other hand, BPD measurements had a lower sensitivity, implying that microcephaly is not a prominent first-trimester feature in these cases. Incorporation of the 'butterfly' sign into the first trimester anatomy scan is simple and can facilitate the identification of the vast majority of fetuses with HPE in the first trimester.

Bilateral posterior parietal polymicrogyria: a mild form of congenital bilateral perisylvian syndrome?

PURPOSE: The main features of congenital bilateral perisylvian syndrome (CBPS) are pseudobulbar palsy, cognitive deficits, epilepsy, and perisylvian abnormalities on imaging studies, however, the clinical spectrum of this syndrome is much wider than previously believed and may vary from minor speech difficulties to severely disabled patients. The objective of this study was to present the different imaging and clinical findings of 17 patients with CBPS, their genetic background, and the occurrence of prenatal injury during their pregnancies. METHODS: We evaluated 17 consecutive patients with CBPS and divided them into two groups according to the imaging findings: (a) diffuse polymicrogyria around the sylvian fissure and (b) posterior polymicrogyria at the posterior parietal regions. They were systematically interviewed regarding history of prenatal events during their pregnancies, family history of speech difficulties, epilepsy, or other neurologic abnormality. RESULTS: There were seven women, ages ranging from 3 to 41 years (mean, 11.5; median, 7 years). Seven patients had bilateral posterior parietal polymicrogyria (BPPP), and 10 had diffuse bilateral perisylvian polymicrogyria. All seven patients with BPPP had only minor speech difficulties, none had epilepsy, and all but one had a family history of epilepsy or cortical dysgenesis. In contrast, 10 patients with diffuse bilateral perisylvian polymicrogyria had pseudobulbar palsy, four had epilepsy, eight had a history of a major prenatal event, and only four had a family history of epilepsy or developmental delay. CONCLUSIONS: These findings suggest that diffuse bilateral perisylvian polymicrogyria appears to be more related to injuries caused by environmental factors, whereas BPPP has a stronger genetic predisposition. In addition, BPPP appears to have a wider clinical spectrum than previously believed, and may represent a milder extreme within the spectrum of CBPS.

Focal polymicrogyria in mother and son.

This 9-year-old boy was admitted at the age of 2 with a diagnosis of congenital hemiparesis while the rest of physical and neurological examination was normal. His score in the Wechsler intelligence scale was 80. Right fronto-parietal cortical dysplasia with hemisphere atrophy was evident by computerized tomography scanning and magnetic resonance imaging. The latter, also disclosed abnormal thick cortex which was interpreted as polymicrogyria or pachygyria. Karyotype was normal. He had a hemifacial motor seizure at the age of 7. At the age of 8 frequent atonic or inhibitory seizures were presented. Asymmetric bilateral spike discharges with high voltage in the right hemisphere during the EEG recording were found. His mother, a 35-year-old woman (Full scale; Adult intelligence scale: 85) also had congenital hemiparesis. She never had seizures and her EEG was normal. Magnetic resonance imaging disclosed right fronto-parietal cortical dysplasia with ipsilateral hemisphere atrophy. Karyotype was normal. Our cases should be interpreted as a familial presentation of the anomaly, probably with autosomal-dominant transmission.