Ultrasound Evaluation of the Central Nervous System

Total Page:16

File Type:pdf, Size:1020Kb

Ultrasound Evaluation of the Central Nervous System Ultrasound Evaluation of the Ultrasound Evaluation of the Central Nervous System Central Nervous System ••CNSCNS malformations are the second most Mani Montazemi, RDMS frequent category of congenital anomaly, Director of Ultrasound Education & Quality Assurancee after congenital heart disease Baylor College of Medicine Division of Maternal-Fetal Medicine ••PoorPoor timing of the examination, rather than Department of Obstetrics and Gynecology Texas Children’s Hospital, Pavilion for Women poor sensitivity, can be an important factor Houston Texas & in failing to detect a CNS abnormality Clinical Instructor Thomas Jefferson University Hospital Radiology Department Fetal Head Philadelphia, Pennsylvania Fetal Head Central Nervous System Brain Development 9 -13 weeks Rhombencephalon 5th Menstrual Week •Gives rise to hindbrain •4th ventricle Arises from the posterior surface of the embryonic ectoderm Mesencephalon •Gives rise to midbrain A small groove is found along •Aqueduct the midline of the embryo and the edges of this groove fold over to form a neuro tube that Prosencephalon gives rise to the fetal spinal •Gives rise to forebrain rd cord and brain •Lateral & 3 ventricles Fetal Head Fetal Head Ventricular view Neural Tube Defects ••LateralLateral ventricles ••ChoroidChoroid plexus Group of malformations: Thalamic view • Anencephaly ••MidlineMidline falx •Anencephaly ••CavumCavum septiseptipellucidi pellucidi ••CephalocelesCephaloceles ••ThalamiThalami ••SpinaSpina bifida Cerebellar view ••CerebellumCerebellum ••CisternaCisterna magna Fetal Head Fetal Head 1 Anencephaly Anencephaly ••LethalLethal abnormality • Defect is covered by a membrane known as ••AbsenceAbsence of the brain & •Defect is covered by a membrane known as lack of the cranial vault cerebrovasculosa ––NoNo soft tissue above ••OftenOften contiguous with cervical spine defect orbits ••TheThe prevalence of anencephaly in the United States in 2001 was 9.40 per 100,000 live births National Center for Health Statistics Fetal Head Fetal Head Anencephaly Anencephaly ••FetalFetal face from the orbits to the ••BulgingBulging eyes chin is usually normal ••LargeLarge tongue ••FrontalFrontal bone is defective above the ••VeryVery short neck orbits ••ParietalParietal bones & occipital bone are absent Fetal Head Fetal Head Anencephaly Anencephaly ••ElevatedElevated MSAFP ––LeakageLeakage thru open neural tube ••PolyhydramniosPolyhydramnios after 25 wks ––FailureFailure to swallow ––ExcessiveExcessive micturition ––FailureFailure of reabsorption of CSF Preterm labor and delivery Routine 2nd ultrasound 96% MSAFP 78% Fetal Head Kooper et al, Prenat Diagn. 2007 Jan;27(1):29-33 Fetal Head 2 Early Recognition of Anencephaly Anencephaly ••MoreMore common ––inin girls than boys ––inin whites than blacks ––inin Irish compared to other ethnic groups ––inin mothers at the younger and older extremes of age ••AssociatedAssociated malformations ––SpinaSpina bifida “crown-chin to crown-rump length ratio” ––CleftCleft lip or palate SepulvedaW, Sebire NJ, FungTY, Pipi E, Nicolaidas KH – Clubfoot Am J Obstet Gynecol. 1997, 176(4):852 –Clubfoot Fetal Head Fetal Head Cephalocele Cephalocele ••ProtrusionProtrusion of intracranial contents through a ••HerniatedHerniated bony defect of the skull ––BrainBrain tissue & CSF ––85% 85% • Size - variable •Size -variable ••EncephaloceleEncephalocele ––MeningesMeninges & CSF ––15% 15% ••CranialCranial meningocele Fetal Head Fetal Head Cephalocele Cephalocele ••75%75% Occipital ••OtherOther CNS anomalies common ––WesternWestern hemisphere ––AbsentAbsent cavum septiseptipellucidi pellucidi ••13%13% Frontal ––AnomalousAnomalous corpus callosum ––AsianAsian population ––DorsalDorsal interhemisphericinterhemisphericcysts cysts ••12%12% Parietal ––ChiarimalformationsChiari malformations ––DandyDandy Walker malformation ––CerebellarcorticalCerebellar cortical dysplasia Fetal Head Fetal Head 3 Occipital meningocele with an Cephalocele associated Dandy-Walker cyst Fetal Head Fetal Head Cephalocele Cephalocele Usually occurs as an isolated lesion, but may be a part of a syndrome ••Meckel-GruberMeckel-Gruber syndrome ––Cepahalocele+Cepahalocele + B/L polycystic Kid + post-axial polydpolydactylyactyly ••Walker-WarburgWalker-Warburg syndrome ––Lissencephaly+Lissencephaly + cerebellarcerebellarhypoplasia+ hypoplasia + Dandy-Walker ccystyst + occular abnormalities ••AmnioticAmniotic band Syndrome ––CanCan involve any part of skull Fetal Head Fetal Head Structural Midline Defects NTD – Cranial Signs ••HighHigh incidence of associated anomalies ••LemonLemon sign: head deformity ––StructuralStructural & chromosomal ••BananaBanana sign: cerebellar deformity ••KaryotypingshouldKaryotyping should be offered ••VentriculomegalyVentriculomegaly Fetal Head Fetal Head 4 Spina Bifida or Spinal Dysraphism ••AA defect that can occur Splayed dorsal ossification centers anywhere along the spinal axis ••LowerLower spine more common than higher ••SpinalSpinal cord and nerve roots exposed Fetal Head Fetal Head Remember Spina Bifida There are several forms of spina bifida ••OssificationOssification occurs from cervical to There are several forms of spina bifida coccygeal •Ventral•Ventraldefectsdefects (rare) ––SplittingSplitting of the vertebral body ––LowerLower levels ossify later ––OccurrenceOccurrence of a cyst that is neuroentericneuroentericin in ––LumbosacralLumbosacral area appears open & wider origin Higher level Lower level •Dorsal•Dorsaldefectsdefects (most common) ––Occulta(closedOcculta (closed spina bifida) ––Aperta(openAperta (open spina bifida) Fetal Head Fetal Head Closed Spina Bifida Skin-Covered NTD ••SpinaSpina bifida occultaocculta(15%) (15%) ––SmallSmall defect completely covered by skin ––Asymptomatic/incidentalAsymptomatic/incidental findings SpinalThere cordis excess extending soft tissuedown belowdistributed L5, compatible broadly ove witr hthe tethering defect Fetal Head Fetal Head 5 Skin-Covered NTD NTD ••LesionLesion level is most predictive of ambulatory function ––HigherHigher lesion levels associated with disphagia ––TheThe absence of covering membrane associated with scoliosis Fetal Head Fetal Head Open Spina Bifida Classifications of Spina Bifida ••SpinaSpina bifida apertaaperta(85%) (85%) AB ––NeuralNeural canal may be exposed ––DefectDefect may be covered by a thin meningealmeningealmembrane membrane A) Meningocele – If the tumor contains purely meningesmeninges && CSFCSF B) Myelomeningocele – protrusion of a sac containing CSF & neural elementelementss Fetal Head Fetal Head Meningocele Vs. Myeloschisis Myelomeningocele It contains solid component due to presence of neural elements within the herniated sac Fetal Head Fetal Head 6 Reversal of Chiari Malformation “Healed” back at birth Fetal Head Fetal Head Cerebellar View - Cisterna Magna ••Size:Size: 2-10 mm ––<< 2 mm spina bifida (ACII) ––>> 10 mm Dandy-Walker T P FH P CSP T FH Fetal Head Fetal Head Arnold-Chiari II Spina Bifida - Arnold-Chiari ••ShallowShallow posterior fossa ••HerniationofHerniation of the cerebellar vermis through ••SmallSmall cerebellar diameter foramen magnum ••“Banana”sign“Banana” sign if severe ••MalformationMalformation is present in almost every case of ••FourthFourth ventricle is displaced downward thoracolumbar, lumbar, and lumbosacral myelomeningocele myelomeningocele inside the neural canal Fetal Head Fetal Head Search for ONTD 7 31 yo woman for “size and dates” evaluation MSAFP was normal No risk factors for fetal anomalies Fetal Head Fetal Head Coronal sonogram of the sacral spine Mid sagittal sonogram of the sacral spine Fetal Head Fetal Head Axial sonogram of the brain Mid sagittal sonogram of the distal spine at the level of ventricular atrium Fetal Head Fetal Head 8 Axial sonogram of the brain WhatSkin is your Covered best guess Spina at the diagnosis? Bifida at the level of posterior fossa Fetal Head Fetal Head Once you have observed the spina bifida cystica, Open neural tube defect WhatWith a closedis thelesion significance one would anticipate of the what is the key sonographic observation that leads to that the mother would demonstrate a normal MSAFP is associatedthe conclusion with that Arnold-Chiari this is a “closed” II malformation lesion? MSAFP test is“normal” only useful for MSAFP?detection of the open NTD The presence of a normal MSAFP does not exclude the possibility of the open NTD because only 80-85% of open Myelomeningoceles are detected by MSAFP testing Fetal Head Fetal Head WhichThe is more AFAFP sensitive is positive for confirming in virtually that the The closedWhich lesions lesion typically has have the a better better prognos is In part this is due to the lack of the Chiari II malformation lesion is “skin ALLcovered”:open NTDsMSAFP or AFAFP? andprognosis: a lack of development open ofor hydrocephalus closed? Fetal Head Fetal Head 9 Dandy-Walker Complex Dandy-Walker Malformation ••DefectDefect in the cerebellar vermis through which the •Dandy-Walker malformation cyst communicates with the 4thth ventricle – Complete or partial agenesis of the cerebellar vermis –Complete or partial agenesis of the cerebellar vermis ••CerebellarCerebellar hemispheres are separated ––EnlargedEnlarged posterior fossa •Dandy-Walker variant ––PartialPartial agenesis of the cerebellar vermis ––WithoutWithout enlargement of the posterior fossa •Mega cisterna magna ––NormalNormal vermis & 4thth ventricle Fetal Head Fetal Head Cisterna Magna – Caution Cisterna Magna – Caution InferiorInferior vermisvermis << 1818 wkswks Reevaluation at 20 to 22 postmenstrual weeks is
Recommended publications
  • Unusual Presentation of Congenital Dermal Sinus: Tethered Spinal Cord with Intradural Epidermoid and Dual Paramedian Cutaneous Ostia
    Neurosurg Focus 33 (4):E5, 2012 Unusual presentation of congenital dermal sinus: tethered spinal cord with intradural epidermoid and dual paramedian cutaneous ostia Case report EFREM M. COX, M.D., KATHLeeN E. KNUDSON, M.D., SUNIL MANJILA, M.D., AND ALAN R. COHEN, M.D. Division of Pediatric Neurosurgery, Rainbow Babies and Children’s Hospital; and Department of Neurological Surgery, The Neurological Institute, University Hospitals Case Medical Center, Cleveland, Ohio The authors present the first report of spinal congenital dermal sinus with paramedian dual ostia leading to 2 intradural epidermoid cysts. This 7-year-old girl had a history of recurrent left paramedian lumbosacral subcutaneous abscesses, with no chemical or pyogenic meningitis. Admission MRI studies demonstrated bilateral lumbar dermal sinus tracts and a tethered spinal cord. At surgery to release the tethered spinal cord the authors encountered para- median dermal sinus tracts with dual ostia, as well as 2 intradural epidermoid cysts that were not readily apparent on MRI studies. Congenital dermal sinus should be considered in the differential diagnosis of lumbar subcutaneous abscesses, even if the neurocutaneous signatures are located off the midline. (http://thejns.org/doi/abs/10.3171/2012.8.FOCUS12226) KEY WORDS • tethered spinal cord • epidermoid cyst • neural tube defect • congenital dermal sinus • dual ostia ONGENITAL dermal sinus tracts of the spine are a Spinal congenital epidermoid cysts arise from epi- rare form of spinal dysraphism, and are hypoth- thelial inclusion
    [Show full text]
  • Facts About Spina Bifida 1995-2009 Bifida 1995-2009
    Facts about Spina Facts about Spina Bifida 1995-2009 Bifida 1995-2009 January 9, 2012 Definition and Types United States Estimates Spina Bifida is a type of neural tube defect where the Each year, about 1,500 babies are born with Spina Bifida in spine does not form properly within the first month of the U.S. The lifetime medical cost associated with caring for pregnancy. There are three types of Spina Bifida: Oc- a child that has been diagnosed with Spina Bifida is estimated 4 culta, Meningocele, and Myelomeningocele. at $460,923 in 2009. Occulta, the mildest form, occurs when there is a In 1992, the Centers for Disease Control and Prevention division between the vertebrae. However, the spi- (CDC) recommended that women of childbearing age con- nal cord does not protrude through the back. The sume 400 micrograms of synthetic folic acid daily. Subse- spinal cord and the nerve usually are normal. This quently, the Food and Drug Administration (FDA) required type of spina bifida usually does not cause any dis- the addition of folate to enriched cereal-grain products by abilities. January 1998. Since then, the incident rate for Spina Bifida of . Meningocele, the least common form, occurs when post-fortification (1998-2006) was 3.68 cases per 10,000 live the covering for the spinal cord but not the spinal births, declined 31% from the pre-fortification (1995-1996) cord protrudes through the back. There is usually rate of 5.04 cases per 10,000 live births.4 little or no nerve damage. This type of spina bifida can cause minor disabilities.
    [Show full text]
  • A Anencephaly
    Glossary of Birth Anomaly Terms: A Anencephaly: A deadly birth anomaly where most of the brain and skull did not form. Anomaly: Any part of the body or chromosomes that has an unusual or irregular structure. Aortic valve stenosis: The aortic valve controls the flow of blood from the left ventricle of the heart to the aorta, which takes the blood to the rest of the body. If there is stenosis of this valve, the valve has space for blood to flow through, but it is too narrow. Atresia: Lack of an opening where there should be one. Atrial septal defect: An opening in the wall (septum) that separates the left and right top chambers (atria) of the heart. A hole can vary in size and may close on its own or may require surgery. Atrioventricular septal defect (endocardial cushion defect): A defect in both the lower portion of the atrial septum and the upper portion of the ventricular septum. Together, these defects make a large opening (canal) in the middle part of the heart. Aniridia (an-i-rid-e-a): An eye anomaly where the colored part of the eye (called the iris) is partly or totally missing. It usually affects both eyes. Other parts of the eye can also be formed incorrectly. The effects on children’s ability to see can range from mild problems to blindness. To learn more about aniridia, go to the U.S. National Library of Medicine website. Anophthalmia/microphthalmia (an-oph-thal-mia/mi-croph-thal-mia): Birth anomalies of the eyes. In anophthalmia, a baby is born without one or both eyes.
    [Show full text]
  • Susceptibility Weighted Imaging: a Novel Method to Determine the Etiology of Aqueduct Stenosis
    THIEME 44 Techniques in Neurosurgery Susceptibility Weighted Imaging: A Novel Method to Determine the Etiology of Aqueduct Stenosis Chanabasappa Chavadi1 Keerthiraj Bele1 Anand Venugopal1 Santosh Rai1 1 Department of Radiodiagnosis, Kasturba Medical College, Manipal Address for correspondence Chanabasappa Chavadi, DNB, Flat No. C- University, Mangalore, India 1-13, 3rd Floor, K.M.C Staff Quarters, Light House Hill Road, Mangalore 575001, India (e-mail: [email protected]). Indian Journal of Neurosurgery 2016;5:44–46. Abstract The stenosis of aqueduct of Sylvius (AS) is a very common cause of obstruction to cerebrospinal fluid. Multiple etiologies are proposed for this condition. Because treatment is specific for correctable disorder, assessment of etiology gains importance. A case of pediatric hydrocephalus was diagnosed with stenosis of AS on magnetic resonance imaging (MRI). Susceptibility-weighted imaging (SWI) demonstrated blooming in the distal aqueduct and lateral ventricle, which was not Keywords seen on routine MRI sequences. The findings suggest that old hemorrhage is a cause ► susceptibility of chemical arachnoiditis and adhesions causing aqueduct stenosis and weighted imaging hydrocephalus. To our knowledge literature is very scarce, wherein SWI is being ► aqueductal stenosis used to confirm blood products as a cause of aqueduct stenosis; hence SWI should be ► magnetic resonance routine protocol in imaging of pediatric hydrocephalus. Etiology, clinical presentation, imaging role of imaging, and, in particular, SWI in evaluation of aqueductal stenosis is ► hydrocephalus discussed. Introduction Case Report Aqueduct of Sylvius (AS) is the narrowest segment of the An 8-month-old child presented with increased head size, cerebrospinal fluid (CSF) pathway and is the most common site developmental delay, and an episode of seizure.
    [Show full text]
  • Maternal Vitamin B12 Status and Risk of Neural Tube Defects in a Population with High Neural Tube Defect Prevalence and No Folic Acid Fortification Anne M
    Maternal Vitamin B12 Status and Risk of Neural Tube Defects in a Population With High Neural Tube Defect Prevalence and No Folic Acid Fortification Anne M. Molloy, Peadar N. Kirke, James F. Troendle, Helen Burke, Marie Sutton, Lawrence C. Brody, John M. Scott and James L. Mills Pediatrics 2009;123;917-923 DOI: 10.1542/peds.2008-1173 The online version of this article, along with updated information and services, is located on the World Wide Web at: http://www.pediatrics.org/cgi/content/full/123/3/917 PEDIATRICS is the official journal of the American Academy of Pediatrics. A monthly publication, it has been published continuously since 1948. PEDIATRICS is owned, published, and trademarked by the American Academy of Pediatrics, 141 Northwest Point Boulevard, Elk Grove Village, Illinois, 60007. Copyright © 2009 by the American Academy of Pediatrics. All rights reserved. Print ISSN: 0031-4005. Online ISSN: 1098-4275. Downloaded from www.pediatrics.org. Provided by Trinity Health Sciences Centre on November 4, 2009 ARTICLE Maternal Vitamin B12 Status and Risk of Neural Tube Defects in a Population With High Neural Tube Defect Prevalence and No Folic Acid Fortification Anne M. Molloy, PhDa, Peadar N. Kirke, FFPHMIb, James F. Troendle, PhDc, Helen Burke, BSocScb, Marie Sutton, MB, MPHb, Lawrence C. Brody, PhDd, John M. Scott, ScDe, James L. Mills, MD, MSc Schools of aMedicine and eImmunology and Biochemistry and Immunology, Trinity College, Dublin, Ireland; bChild Health Epidemiology Unit, Health Research Board, Dublin, Ireland; cDivision of Epidemiology, Statistics, and Prevention Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; dMolecular Pathogenesis Section, Genome Technology Branch, National Human Genome Research Institute, Bethesda, Maryland The authors have indicated they have no financial relationships relevant to this article to disclose.
    [Show full text]
  • Pushing the Limits of Prenatal Ultrasound: a Case of Dorsal Dermal Sinus Associated with an Overt Arnold–Chiari Malformation and a 3Q Duplication
    reproductive medicine Case Report Pushing the Limits of Prenatal Ultrasound: A Case of Dorsal Dermal Sinus Associated with an Overt Arnold–Chiari Malformation and a 3q Duplication Olivier Leroij 1, Lennart Van der Veeken 2,*, Bettina Blaumeiser 3 and Katrien Janssens 3 1 Faculty of Medicine, University of Antwerp, 2610 Wilrijk, Belgium; [email protected] 2 Department of Obstetrics and Gynaecology, University Hospital Antwerp, 2650 Edegem, Belgium 3 Department of Medical Genetics, University Hospital and University of Antwerp, 2650 Edegem, Belgium; [email protected] (B.B.); [email protected] (K.J.) * Correspondence: [email protected] Abstract: We present a case of a fetus with cranial abnormalities typical of open spina bifida but with an intact spine shown on both ultrasound and fetal MRI. Expert ultrasound examination revealed a very small tract between the spine and the skin, and a postmortem examination confirmed the diagnosis of a dorsal dermal sinus. Genetic analysis found a mosaic 3q23q27 duplication in the form of a marker chromosome. This case emphasizes that meticulous prenatal ultrasound examination has the potential to diagnose even closed subtypes of neural tube defects. Furthermore, with cerebral anomalies suggesting a spina bifida, other imaging techniques together with genetic tests and measurement of alpha-fetoprotein in the amniotic fluid should be performed. Citation: Leroij, O.; Van der Veeken, Keywords: dorsal dermal sinus; Arnold–Chiari anomaly; 3q23q27 duplication; mosaic; marker chro- L.; Blaumeiser, B.; Janssens, K. mosome Pushing the Limits of Prenatal Ultrasound: A Case of Dorsal Dermal Sinus Associated with an Overt Arnold–Chiari Malformation and a 3q 1.
    [Show full text]
  • Sylvian Aqueduct Syndrome and Global Rostral Midbrain Dysfunction Associated with Shunt Malfunction
    Sylvian aqueduct syndrome and global rostral midbrain dysfunction associated with shunt malfunction Giuseppe Cinalli, M.D., Christian Sainte-Rose, M.D., Isabelle Simon, M.D., Guillaume Lot, M.D., and Spiros Sgouros, M.D. Department of Pediatric Neurosurgery and Pediatric Radiology, Hôpital Necker•Enfants Malades, Université René Decartes; and Department of Neurosurgery, Hôpital Lariboisiere, Paris, France Object. This study is a retrospective analysis of clinical data obtained in 28 patients affected by obstructive hydrocephalus who presented with signs of midbrain dysfunction during episodes of shunt malfunction. Methods. All patients presented with an upward gaze palsy, sometimes associated with other signs of oculomotor dysfunction. In seven cases the ocular signs remained isolated and resolved rapidly after shunt revision. In 21 cases the ocular signs were variably associated with other clinical manifestations such as pyramidal and extrapyramidal deficits, memory disturbances, mutism, or alterations in consciousness. Resolution of these symptoms after shunt revision was usually slow. In four cases a transient paradoxical aggravation was observed at the time of shunt revision. In 11 cases ventriculocisternostomy allowed resolution of the symptoms and withdrawal of the shunt. Simultaneous supratentorial and infratentorial intracranial pressure recordings performed in seven of the patients showed a pressure gradient between the supratentorial and infratentorial compartments with a higher supratentorial pressure before shunt revision. Inversion of this pressure gradient was observed after shunt revision and resolution of the gradient was observed in one case after third ventriculostomy. In six recent cases, a focal midbrain hyperintensity was evidenced on T2-weighted magnetic resonance imaging sequences at the time of shunt malfunction. This rapidly resolved after the patient underwent third ventriculostomy.
    [Show full text]
  • Neural Tube Defects, Folic Acid and Methylation
    Int. J. Environ. Res. Public Health 2013, 10, 4352-4389; doi:10.3390/ijerph10094352 OPEN ACCESS International Journal of Environmental Research and Public Health ISSN 1660-4601 www.mdpi.com/journal/ijerph Review Neural Tube Defects, Folic Acid and Methylation Apolline Imbard 1,2,*, Jean-François Benoist 1 and Henk J. Blom 2 1 Biochemistry-Hormonology Laboratory, Robert Debré Hospital, APHP, 48 bd Serrurier, Paris 75019, France; E-Mail: [email protected] 2 Metabolic Unit, Department of Clinical Chemistry, VU Free University Medical Center, De Boelelaan 1117, Amsterdam 1081 HV, The Netherlands; E-Mail: [email protected] * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +33-1-4003-4722; Fax: +33-1-4003-4790. Received: 27 July 2013; in revised form: 30 August 2013 / Accepted: 3 September 2013 / Published: 17 September 2013 Abstract: Neural tube defects (NTDs) are common complex congenital malformations resulting from failure of the neural tube closure during embryogenesis. It is established that folic acid supplementation decreases the prevalence of NTDs, which has led to national public health policies regarding folic acid. To date, animal studies have not provided sufficient information to establish the metabolic and/or genomic mechanism(s) underlying human folic acid responsiveness in NTDs. However, several lines of evidence suggest that not only folates but also choline, B12 and methylation metabolisms are involved in NTDs. Decreased B12 vitamin and increased total choline or homocysteine in maternal blood have been shown to be associated with increased NTDs risk. Several polymorphisms of genes involved in these pathways have also been implicated in risk of development of NTDs.
    [Show full text]
  • Encephalocele
    Encephalocele An encephalocele (pronounced en-sef-a-lo-seal) is a rare birth defect affecting the brain. It is one type of neural tube defect. The neural tube What is it? is a channel that usually folds and closes during the first few weeks of pregnancy. Normally, it forms the brain and spinal cord. Neural tube defects occur when the neural tube does not close as a baby grows in the womb. Neural tube defects can range in size and occur anywhere along the neck or spine. An encephalocele is a sac-like projection of brain tissue and membranes outside the skull. Encephaloceles can be on any part of the head but often occur on the back of the skull, as pictured below. Encephalocele Image courtesy of the Centers for Disease Control and Prevention, National Center on Birth Defects and Developmental Disabilities Children with an encephalocele may have additional birth defects, such as hydrocephalus, microcephaly, seizures, developmental delay, intellectual disability, and problems with coordination or movement. Hydrocephalus is extra fluid around the brain and is also called “water on the brain.” Microcephaly is a small head size. About 375 babies in the United States are born with an encephalocele How common is it? each year. That’s about 1 in every 10,000 babies. The cause of encephaloceles is unknown in most babies. There may be many factors that cause it. Taking folic acid can decrease the chance of having a baby with neural tube defects. Women who want to become What causes it? pregnant or are pregnant should take folic acid every day.
    [Show full text]
  • CONGENITAL ABNORMALITIES of the CENTRAL NERVOUS SYSTEM Christopher Verity, Helen Firth, Charles Ffrench-Constant *I3
    J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.74.suppl_1.i3 on 1 March 2003. Downloaded from CONGENITAL ABNORMALITIES OF THE CENTRAL NERVOUS SYSTEM Christopher Verity, Helen Firth, Charles ffrench-Constant *i3 J Neurol Neurosurg Psychiatry 2003;74(Suppl I):i3–i8 dvances in genetics and molecular biology have led to a better understanding of the control of central nervous system (CNS) development. It is possible to classify CNS abnormalities Aaccording to the developmental stages at which they occur, as is shown below. The careful assessment of patients with these abnormalities is important in order to provide an accurate prog- nosis and genetic counselling. c NORMAL DEVELOPMENT OF THE CNS Before we review the various abnormalities that can affect the CNS, a brief overview of the normal development of the CNS is appropriate. c Induction—After development of the three cell layers of the early embryo (ectoderm, mesoderm, and endoderm), the underlying mesoderm (the “inducer”) sends signals to a region of the ecto- derm (the “induced tissue”), instructing it to develop into neural tissue. c Neural tube formation—The neural ectoderm folds to form a tube, which runs for most of the length of the embryo. c Regionalisation and specification—Specification of different regions and individual cells within the neural tube occurs in both the rostral/caudal and dorsal/ventral axis. The three basic regions of copyright. the CNS (forebrain, midbrain, and hindbrain) develop at the rostral end of the tube, with the spinal cord more caudally. Within the developing spinal cord specification of the different popu- lations of neural precursors (neural crest, sensory neurones, interneurones, glial cells, and motor neurones) is observed in progressively more ventral locations.
    [Show full text]
  • Chiari Type II Malformation: Past, Present, and Future
    Neurosurg Focus 16 (2):Article 5, 2004, Click here to return to Table of Contents Chiari Type II malformation: past, present, and future KEVIN L. STEVENSON, M.D. Children’s Healthcare of Atlanta, Atlanta, Georgia Object. The Chiari Type II malformation (CM II) is a unique hindbrain herniation found only in patients with myelomeningocele and is the leading cause of death in these individuals younger than 2 years of age. Several theories exist as to its embryological evolution and recently new theories are emerging as to its treatment and possible preven- tion. A thorough understanding of the embryology, anatomy, symptomatology, and surgical treatment is necessary to care optimally for children with myelomeningocele and prevent significant morbidity and mortality. Methods. A review of the literature was used to summarize the clinically pertinent features of the CM II, with par- ticular attention to pitfalls in diagnosis and surgical treatment. Conclusions. Any child with CM II can present as a neurosurgical emergency. Expeditious and knowledgeable eval- uation and prompt surgical decompression of the hindbrain can prevent serious morbidity and mortality in the patient with myelomeningocele, especially those younger than 2 years old. Symptomatic CM II in the older child often pre- sents with more subtle findings but rarely in acute crisis. Understanding of CM II continues to change as innovative techniques are applied to this challenging patient population. KEY WORDS • Chiari Type II malformation • myelomeningocele • pediatric The CM II is uniquely associated with myelomeningo- four distinct forms of the malformation, including the cele and is found only in this population. Originally de- Type II malformation that he found exclusively in patients scribed by Hans Chiari in 1891, symptomatic CM II ac- with myelomeningocele.
    [Show full text]
  • Non-Tumoural Aqueduct Stenosis and Normal Pressure Hydrocephalus in the Elderly
    J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.49.5.529 on 1 May 1986. Downloaded from Journal of Neurology, Neurosurgery, and Psychiatry 1986;49:529-535 Non-tumoural aqueduct stenosis and normal pressure hydrocephalus in the elderly JAN VANNESTE, RON HYMAN From the Department of Neurology, Sint Lucas Ziekenhuis, Amsterdam, and the Department of Biological Psychiatry, University Hospital, Utrecht, The Netherlands SUMMARY From 1981 to 1985 a prospective study on normal pressure hydrocephalus was per- formed. One of the aims of this study was to determine the site of CSF obstruction. Among 17 consecutive patients with a tentative diagnosis of normal pressure hydrocephalus, nine appeared to have non-communicating hydrocephalus most probably due to primary non-tumoural aqueduct stenosis. This unexpected finding provides evidence that non-tumoural aqueduct stenosis is a frequent cause of normal pressure hydrocephalus in older patients. Some clinical, aetiological and therapeutic aspects in this particular subgroup are discussed. Normal pressure hydrocephalus is a syndrome com- stenosis. All of these were aged 60 years or over. This Protected by copyright. bining the non-specific clinical triad ofgait instability, particular group is discussed. mild to moderate mental deterioration and occa- sionally urinary incontineiice with chronic hydro- Patients cephalus and-normal CSF pressure at random lumbar punctures. - This syndrome is known to occur in The clinical profile was similar in all patients and is sum- both non-communicating and communicating hydro- marised in table 1. Two illustrative cases are briefly cephalus,1 4-6 but most articles on normal pressure described. Case 2 A 69-year-old man complained of slight gait hydrocephalus deal with communicating hydro- difficulties for one year.
    [Show full text]