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Re: Decreased Sulci BE CAREFUL!From: James Smeltzer (James.Smeltzer@wellstar.org)Mon Nov 14 08:33:32 2005
Hi! Frank is right in general! Shape of sulci/gyri along the normal course of the cingulate gyrus in a radial finger-like pattern rather than the normal ellipsoidal course parallel to the cranium may be the easiest finding to show an agenesis of the corpus callosum. The pattern and size of the cerebellum and ventricles, and other associatred anomalies can predict some of the more severe syndromes. With those exceptions, and probably others that should be positively diagnosed only by a team of sonologist, pediatric neurologyst and dysmorphologist, the prediction of abnormal development in the absence of other anomalies or a clear syndrome is usually going to be wrong, misleading and probably harmful. I will never forget the time one of the fellows counselled a patient with isolated ventriculomegaly and was hanging crepe. The couple wanted reassurance that everything was all right or they were going to terminate. I heard about that decision, rescanned the baby and found nothing but mild ventriculomegaly. I told them that seven out of eight of these babies turned out to be completely normal, and that I saw nothing else to suggest a problem, but their initial counselling stuck. They went to another large eastern town for an abortion and, en route, got another targeted sonogram and the same information I had given them. They changed their minds about termination. The kid showed up on a national news exposee on diagnostic errors of ultrasound playing on a gym set, completely normal. The voice over was the couple talking about how they were told their child was going to be abnormal ant that they should terminate - only half true, but the half they remembered and were going to act on. If lissencephaly is considered, looking for associated anomalies and family history may be helpful. DO NOT let that word pass your lips unless you are VERY experienced in prenatal diagnosis, and are fairly sure of the diagnosis. SEND IT ON, PLEASE. MRI may be useful in nailing down the diagnosis. Trans-vaginal sonography is essential for the evaluation of the cerebrum of a cephalic fetus. The incidence range is 4 to 11 per million, which means that the two cases I have seen are my quota for a lifetime. Drs. Silva and Jeanty have a review of Type 1 on TheFetus.net: THe photos are the same from Blas http://www.thefetus.net/page.php?id=124 Drs Blas and Eik-Ness have a review on TheFetus.net: http://www.thefetus.net/page.php?id=125 Dr Fong & al at Sick Kids in TOronto did a nice study working backwards from a positive diagnosis, and their study may be helpful. See: http://www.lissencephaly.org/about/lissen.htm#intro http://www.lissencephaly.org/medical/info/classlis.htm http://www3.interscience.wiley.com/cgi-bin/abstract/109855629/ABSTRACT http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8306353&dopt=Abstract Hope this helps! Jim Smeltzer Ultrasound in Obstetrics and Gynecology Volume 24, Issue 7 , Pages 716 - 723 Published Online: 7 Dec 2004 Prenatal ultrasound findings of lissencephaly associated with Miller-Dieker syndrome and comparison with pre- and postnatal magnetic resonance imaging K. W. Fong 1 *, S. Ghai 1, A. Toi 1, S. Blaser 4, E. J. T. Winsor 2 3, D. Chitayat 3 5 Abstract Objective To report on the prenatal ultrasound findings in fetuses with lissencephaly associated with Miller-Dieker syndrome (MDS) and to compare these findings with those of magnetic resonance imaging (MRI). Methods Cases of MDS confirmed by postnatal chromosome microdeletion analysis were identified through review of patient records. Prenatal ultrasound scans were reviewed retrospectively by two radiologists. For cerebral cortical development, the Sylvian, parieto-occipital and calcarine fissures, and the cingulate sulcus and sulci over the cerebral convexity were evaluated. If one or more of these fissures or sulci were not visualized at the expected gestational age or their appearance was abnormal for gestational age, cortical development was considered delayed. Prenatal and postnatal MRI examinations were reviewed by a pediatric neuroradiologist. Results There were seven cases of MDS. In three cases, the prenatal diagnosis of agyria/lissencephaly was prospectively suspected by ultrasound at 23, 26 and 30 weeks, and subsequently confirmed by prenatal MRI. When we retrospectively reviewed the prenatal ultrasound scans of all fetuses, all had delayed cortical development identified on ultrasound performed after 23 weeks' gestation. In all cases the Sylvian fissure was abnormal on both ultrasound and MRI. In one fetus, a normal cortical appearance for gestational age was seen at the initial 20-week ultrasound examination, but delayed cortical development was identified at a 24-week scan. Mild ventriculomegaly was seen in six fetuses and dysgenesis of the corpus callosum in one. Extracranial abnormalities were detected in five fetuses. Delayed cortical development was seen in two fetuses with mild ventriculomegaly, but no other fetal anomalies. Conclusions In fetuses with MDS, delayed cortical development can be suspected on ultrasound as early as 23 weeks' gestation. This finding warrants further investigations including MRI and FISH analysis for chromosome 17p13.3 deletion. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd. Dr. Kojima & al have diagnosed Type II in utero: Kojima K, Suzuki Y, Seki K, Yamamoto T, Sato T, Tanaka T, Suzumori K: Prenatal Diagnosis of Lissencephaly (Type II) by Ultrasound and Fast Magnetic Resonance Imaging. Fetal Diagn Ther 2002;17:34-36 (DOI: 10.1159/000048003) Abstract We report a case of lissencephaly which could be diagnosed by detailed examination during pregnancy. We first found bilateral enlarged ventricles in the fetus by routine abdominal ultrasonography at mid-pregnancy. Fast scanning MRI subsequently allowed confirmation of a diagnosis of lissencephaly during pregnancy. Copyright © 2002 S. Karger AG, Basel Childs Nerv Syst. 1993 Nov;9(7):391-3. Related Articles, Links Neuroimaging in lissencephalies. Schuierer G, Kurlemann G, von Lengerke HJ. Institut fur Klinische Radiologie, Westfalische Wilhelms-Universitat, Munster, Germany. Based on the published literature and on our own experiences in the imaging of lissencephalies with ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) we propose a strategy for the use of the different methods depending on the clinical symptoms and the age of the patient. In newborns and babies with suspected lissencephaly ultrasound should be used as the first method. If there is a cortical malformation and a more thorough examination seems necessary, CT can be used in type I lissencephaly. However, due to its excellent grey-white matter contrast MRI is the best method for imaging of lissencephalies. Especially in the diagnosis of type II lissencephaly, MRI is definitely superior to CT and US, and so it should be used in all patients with Walker-Warburg syndrome and other congenital muscular dystrophies as well as in all doubtful cases. It must always be remembered that the extent of the cortical dysplasias is quite variable, as is the presence of further malformations. PMID: 8306353 [PubMed - indexed for MEDLINE] Childs Nerv Syst. 1993 Nov;9(7):391-3. Related Articles, Links Neuroimaging in lissencephalies. Schuierer G, Kurlemann G, von Lengerke HJ. Institut fur Klinische Radiologie, Westfalische Wilhelms-Universitat, Munster, Germany. Based on the published literature and on our own experiences in the imaging of lissencephalies with ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) we propose a strategy for the use of the different methods depending on the clinical symptoms and the age of the patient. In newborns and babies with suspected lissencephaly ultrasound should be used as the first method. If there is a cortical malformation and a more thorough examination seems necessary, CT can be used in type I lissencephaly. However, due to its excellent grey-white matter contrast MRI is the best method for imaging of lissencephalies. Especially in the diagnosis of type II lissencephaly, MRI is definitely superior to CT and US, and so it should be used in all patients with Walker-Warburg syndrome and other congenital muscular dystrophies as well as in all doubtful cases. It must always be remembered that the extent of the cortical dysplasias is quite variable, as is the presence of further malformations. PMID: 8306353 [PubMed - indexed for MEDLINE] Ultrasound Obstet Gynecol. 1998 Oct;12(4):276-9. Related Articles, Links Antenatal diagnosis of isolated lissencephaly by ultrasound and magnetic resonance imaging. Greco P, Resta M, Vimercati A, Dicuonzo F, Loverro G, Vicino M, Selvaggi L. Institute of Obstetrics and Gynecology, University of Bari, Italy. Lissencephaly (agyria) is a cortical dysplasia associated with a disturbance in the migration of neocortical neurons. Because of abnormal sonographic findings in the brain of a 24-week fetus, we carried out serial magnetic resonance imaging (MRI) examinations which raised the suspicion of isolated lissencephaly. In the second trimester, an area of damage depicted as low-intensity signals was identified by MRI inside the cortical parenchyma. In the same cortical area, agyria was detected later in pregnancy, and postnatally calcification was observed by computerized tomography (CT) scan. We believe that ultrasound and targeted MRI examination can improve our understanding of some disorders of neuronal migration and that earlier diagnosis is feasible if both methods are employed and interpreted by sound criteria.
-- James S. Smeltzer, MD, FACOG, SMFM Consultant, Maternal Fetal Medicine Wellstar Physicians' Group Northwest Women's Care 787 Campbell Hill St Marietta GA 30060 James.Smeltzer@wellstar.org VM 678-290-3035 Off 770-528-0260 Page 404-318-3451
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