DOCSLIB.ORG

Craniopagus Twins: Surgical Anatomy and Embryology and Their Implications

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Craniopagus Twins: Surgical Anatomy and Embryology and Their Implications J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.39.1.1 on 1 January 1976. Downloaded from Journal of Neurology, Neurosurgery, and Psychiatry, 1976, 39, 1-22 Craniopagus twins: surgical anatomy and embryology and their implications J. E. A. O'CONNELL1 From the Department of Neurological Surgery, St. Bartholomew's Hospital, London SYNOPSIS Craniopagus is of two types, partial and total. In the partial form the union is of limited extent, particularly as regards its depth, and separation can be expected to be followed by the survival of both children to lead normal lives. In the total form, of which three varieties can be recognized, the two brains can be regarded as lying within a single cranium and a series of gross intracranial abnormalities develops. These include deformity of the skull base, deformity and displacement of the cerebrum, and a gross circulatory abnormality. It is considered that these and other abnormalities, unlike the primary defect, which is defined, are secondary ones; explanations for them, based on anatomy and embryology, are put forward. The implications of the various anomalies are discussed and the ethical aspects of attempted separation in these major unions considered. Protected by copyright. The birth of conjoined twins is an infrequent future. The practical problems resulting from occurrence. Its incidence is estimated as one in disordered anatomy are discussed and their 50 000 births (Potter, 1961). The union is a solution, complete or partial, described. The cephalic one in 2.0% which makes the incidence abnormal anatomy is analysed and related to of craniopagus twins one in 2.5 million births. embryological development. The nature of the The occurrence is thus a rarity, although, since primary congenital defect is discussed. A classi- numerous cases are not reported in the literature, fication of craniopagus is produced, differentia- it is likely that its frequency is greater than these ting partial from total unions so that confusion figures indicate. Should the twins survive, the in the literature between the different types of possibility of their separation will be raised with case may be avoided in the future. Finally, the a neurosurgeon and if the union is an extensive ethical problems which arise in connection with one, as it commonly is, the problem is a daunt- the surgical treatment of total vertical cranio- ing one. Not only is it unlikely that the surgeon pagus are discussed. http://jnnp.bmj.com/ will have had any previous experience of the con- The material studied has been the records of dition, but until recent times there was little in three personally treated cases of craniopagus the literature to guide him. The first report mentioned above and previously reported. For (Grossman et al., 1953) described the separation the present paper, certain clinical features and of a pair of such twins with the survival of one results of investigation as well as operative of them. Subsequently (O'Connell, 1964; findings are reconsidered. The postmortem O'Connell, 1968) came descriptions of separation studies made in each of the twins of the second on October 1, 2021 by guest. operations in three cases of total vertical and third pairs who died during surgery are craniopagus, one of each pair surviving. This correlated with the other findings. In addition, study of personal material has been made in the through the kindness of colleagues, postmortem certain knowledge that further attempts to studies of another example of craniopagus, not separate craniopagus twins will be made in the seen during life, have been possible. The small but increasing literature dealing with cranio- I Address for reprint requests: Fishing Cottage, ltchen Abbas, near Winchester, Hampshire. pagus has been reviewed and where appropriate (Accepted 16 July 1975.) related to the present work. 1 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.39.1.1 on 1 January 1976. Downloaded from 2 J. E. A. O'Connell CLASSIFICATION OF CRANIOPAGUS much of the dura mater of one twin from that of the other. The result after separation was excellent in According to the site of the cephalic junction, it one child but the other, whose superior sagittal sinus has been customary to classify cases of cranio- was possibly injured at operation, has survived pagus as parietal, frontal, or occipital, over 60% disabled and had repeated operations for cerebro- of them being parietal. This method ofclassifica- spinal fluid fistula and ventricular dilatation (Fig. Ia). tion is inadequate since it makes no distinction The second pair (Baldwin and Dekaban, 1958) had a between unions of limited superficial extent and frontal union (Fig. 1 b); this was an oval area measur- depth and the extensive unions in which the two ing 8.0 cm x 6.5 cm and united the children's right cranial cavities are in wide connection. It is frontal regions. There was a dural defect within this area but intact leptomeninges covered the exposed proposed that the cases be placed in two groups, frontal cortex of each cerebrum. Separation and partial and total. In partial craniopagus, the survival of both were achieved without defect and surface area of the heads involved is usually they were developing well seven years later. In the relatively small and the crania may be intact and third pair (Wolfowitz et al., 1968), the union was also simply fused in this area; or there may be a a frontal one but more localized (Fig. ic), so that cranial defect and the dura mater of the twins there was some mobility of one head from the other. be in contact and possibly fused within the The essential of the operative procedure was the defect; or the dura mater may be absent and the separation of a relatively small area of dura mater of leptomeninges covering the related areas of one child from a similar area in the other, and this cerebra are in contact with one another. The was achieved with the survival ofboth children. From what it will be realized that follows, such partial Protected by copyright. abnormality extends no deeper and is, in fact, unions are an entirely different problem from the simply a defect of cerebral coverings and fre- total ones. quently a limited one. It should be noted that occasionally the junction in partial craniopagus In addition to these three cases of localized may appear to be extensive, yet radiological craniopagus treated surgically in recent years, examination reveals that a layer of bone repre- others must clearly have been born, if the senting the fused skulls of the twins extends over incidence of craniopagus twins is one in two- much of the junction. Such a superficial union and-a-half million births. Of a series of 22 cases must, of course, be classified as partial cranio- (Robertson, 1953) two were frontal and five pagus. In total craniopagus there is an extensive occipital. Details are not available, but it is area of surface involvement and the cranial likely that several of these were cases of the cavities are widely connected; indeed, the two partial form. No doubt there have been other brains are contained within a common cranium. reports of cases of localized craniopagus This leads to the very important alterations in throughout the world but the literature is not a cerebral development and circulation which will true guide to the frequency ofsuch abnormalities. be described later in detail. Partial craniopagus http://jnnp.bmj.com/ is thus essentially an extracranial abnormality 2. Total craniopagus and total vertical craniopagus a gross intracranial In this variety the union is extensive. It is one. The partial unions may be frontal, parietal, commonly vertical and described in the literature or occipital; total craniopagus is, from its as parietal. However, very widespread unions nature, likely to be biparietal and, since it is a can occur elsewhere. Klar (1963) described an very wide union, it is thought can better be extensive frontal union and the author has seen described as vertical. radiographs of twins with an extensive parieto- on October 1, 2021 by guest. occipitotemporal union. In some of the reports 1. Partial craniopagus of such extensive unions in situations other than Three pairs of twins of this type have been the vertical one (Sapinski, 1966), it seems possible reported in the literature, all having been that the wide union was vertical at an early treated surgically. developmental stage. Later intrauterine forces The first of these (Voris et al., 1957) was a central altered the relationship of the long axes of the vertical union in which the dura mater of both infants to one another so that a gross angulation children was intact and a thin layer ofskull separated occurred at the site of junction between the J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.39.1.1 on 1 January 1976. Downloaded from Craniopagus twins: surgical anatomy and embryology and their implications 3 4 H.K I ( 1i J ..... .; . _r >' > A Protected by copyright. '^''M-. C--i<>wi;FR $ ....... ..4Fr . / .......... a} X '; 8 Al oV'. ( I-,) (p A Y .; f: VIV_E i .t.fi. +kG 'x2''@} http://jnnp.bmj.com/ rIB on October 1, 2021 by guest. 'C Wv>%'.A.. ( K,. FIG. 1 Partial craniopagus: (a) Voris et al. (1957); (b) Baldwin and Dekaban (1958); (c) Wolfowitz et al. (1968). J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.39.1.1 on 1 January 1976. Downloaded from 4 J. E. A. O'Connell the skull is involved and the appearance is that of a common cranium for the two brains. Examination of personal material suggests that according to the degree of rotation of one twin's head on that of the other, around the longi- tudinal axis, three types of total vertical cranio- pagus can be distinguished.
Load more

Recommended publications
  • Representations of Conjoined Twins
    University of Wollongong Research Online University of Wollongong Thesis Collection 1954-2016 University of Wollongong Thesis Collections 2015 Representations of conjoined twins Claire Marita Fletcher University of Wollongong Follow this and additional works at: https://ro.uow.edu.au/theses University of Wollongong Copyright Warning You may print or download ONE copy of this document for the purpose of your own research or study. The University does not authorise you to copy, communicate or otherwise make available electronically to any other person any copyright material contained on this site. You are reminded of the following: This work is copyright. Apart from any use permitted under the Copyright Act 1968, no part of this work may be reproduced by any process, nor may any other exclusive right be exercised, without the permission of the author. Copyright owners are entitled to take legal action against persons who infringe their copyright. A reproduction of material that is protected by copyright may be a copyright infringement. A court may impose penalties and award damages in relation to offences and infringements relating to copyright material. Higher penalties may apply, and higher damages may be awarded, for offences and infringements involving the conversion of material into digital or electronic form. Unless otherwise indicated, the views expressed in this thesis are those of the author and do not necessarily represent the views of the University of Wollongong. Recommended Citation Fletcher, Claire Marita, Representations of conjoined twins, Master of Arts in Creative Writing thesis, Faculty of Law, Humanities and the Arts, University of Wollongong, 2015. https://ro.uow.edu.au/theses/ 4691 Research Online is the open access institutional repository for the University of Wollongong.
    [Show full text]
  • The Role of Rapid Tissue Expansion in Separating Xipho-Omphalopagus Conjoined Twins in Vietnam
    Breast/Trunk Case Report The role of rapid tissue expansion in separating xipho-omphalopagus conjoined twins in Vietnam Tran Thiet Son1,2,3, Pham Thi Viet Dung1, Ta Thi Hong Thuy1, Vu Duy Kien4, Nguyen Thanh Liem5 1Department of Plastic and Reconstructive Surgery, Hanoi Medical University Hospital, Hanoi; 2Department of Plastic Reconstructive Aesthetic Surgery, Saint Paul Hospital, Hanoi; 3Department of Plastic and Reconstructive Surgery, Bach Mai Hospital, Hanoi; 4OnCare Medical Technology Company Limited, Hanoi; 5Department of Pediatric Surgery, Vietnam National Children’s Hospital, Hanoi, Vietnam Conjoined twins are rare, and each set of conjoined twins has a unique conjoined anatomy. It Correspondence: Tran Thiet Son is necessary to perform separation to increase the chance of patient survival. Tissue expan- Department of Plastic and Reconstructive Surgery, Hanoi sion is an advanced technique for providing sufficient soft tissue and skin for wound closure. Medical University Hospital, No.1 Ton We report the successful application of rapid tissue expansion in 10-month-old xipho-om- That Tung Street, Hanoi 116001, phalopagus conjoined twins in Vietnam. A tissue expander was placed on the anterior body Vietnam between the sternum and umbilicus with a baseline of 70 mL sterile saline (0.9% NaCl). The Tel: +84-903444244 E-mail: [email protected] first injection into the tissue expander began on the 6th day after expander insertion, and in- jections continued every 2 days with approximately 30–70 mL per injection according to the expansion of the skin. The expander reached 335 mL after six injections and within 10 days. In order to prepare for surgical separation, expansion was completed on the 15th day after insertion.
    [Show full text]
  • Twin-To-Twin Transfusion Syndrome: an Overview Richa Saxena1, Kanav Midha2
    REVIEW ARTICLE Twin-to-twin Transfusion Syndrome: An Overview Richa Saxena1, Kanav Midha2 ABSTRACT Twin-to-twin transfusion syndrome (TTTS) is a severe problem that affects 10–15% of monochorionic (MC) multiple pregnancies. Connecting placental vessels on chorionic plate between donor and recipient twin is accountable for inequality of blood flow. There is an indication for the superiority of fetoscopic laser ablation over serial amnioreductions regarding survival and neurological outcome for stages II–IV TTTS. However, the optimal management of stage I is still debated. In this review, we discuss the basics of twin gestation, optimal management, pathophysiology, long-term neurodevelopmental outcome, and future aspects of TTTS. Keywords: Dizygotic, Fetus, Gestation, Monozygotic, Twin–twin transfusion syndrome. World Journal of Anemia (2018): 10.5005/jp-journals-10065-0041 INTRODUCTION 1Jaypee Brothers Medical Publishers, New Delhi, India Development of two or more embryos simultaneously in a pregnant 2Department of Pharmaceutical Sciences, Chitkara University, uterus is termed as “multifetal gestation.” Development of two Chandigarh, India fetuses (whether through monozygotic or dizygotic fertilization) Corresponding Author: Richa Saxena, Jaypee Brothers Medical simultaneously is known as twin gestation; development of three Publishers, New Delhi, India, Phone: +91 9971234834, e-mail: synapse94@ fetuses simultaneously as triplets; four fetuses as quadruplets; five hotmail.com fetuses as quintuplets, and so on. The incidence of twin gestation How to cite this article: Saxena R, Midha K. Twin-to-twin Transfusion is about 1 per 80 live births. The incidence varies among different Syndrome: An Overview. World J Anemia 2018;2(3–4):96–102. countries and ethnic groups, with the incidence being highest Source of support: Nil in African countries, lowest in Japan and intermediate among Conflict of interest: None Caucasians.
    [Show full text]
  • Parapagus Conjoined Twins: Complicated Anatomy Precludes Separation
    Case Report Full text online at http://www.jiaps.com Parapagus conjoined twins: Complicated anatomy precludes separation Arbinder K. Singhal, Gautam S. Agarwal, Shilpa Sharma, Arun K. Gupta*, Devendra K. Gupta Departments of Pediatric Surgery and *Radiodiagnosis, All India Institute of Medical Sciences, New Delhi, India Correspondence: Dr. D. K. Gupta, Department of Pediatric Surgery, All India Institute of Medical Sciences, New Delhi - 110 029, India. E-mail: [email protected] ABSTRACT A parapagus set of male conjoined twins was brought to our institution at 12 h after birth. An extensive sharing of the abdominal viscera (single liver, hindgut), abdominal aorta, pelvis (single rectum and anus), genitalia (one set) and vertebral column was found. The surgical separation was not considered due to medical and ethical issues. KEY WORDS: Parapagus, conjoint twins INTRODUCTION were cyanosed. The right twin was intubated and required ventilation for 24 h; after that, both the babies Conjoined twins occur in one in 50-100,000 live births remained stable. and are now thought to result from the fission of the notochordal anlage; followed by subsequent fusion of Babygram showed two separate vertebral columns with the embryos.[1] Parapagus twins joined anterolaterally scoliosis and separate hemisacra, which joined distally result from two nearly parallel notochords in close [Figure 2]. Echocardiogram, ultrasonogram with doppler proximity. This anomaly represents less than 0.5% of and contrast enhanced computed tomographic (CECT) all reported cases of conjoined twins.[2] We present one scan revealed two structurally normal hearts with liver such surviving set of conjoined twins. wedged in between; two separate thoracic aortas; two separate inferior vena cavae with ipsilateral drainage of MATERIALS AND METHODS hepatic veins; a central large liver with a single gall bladder; single spleen on the left side; and two normal A set of male conjoined twins, born to a third gravida kidneys, one in each flank.
    [Show full text]
  • The First Successful Separation of Conjoined Twins in 1689: Some Additions and Corrections
    The First Successful Separation of Conjoined Twins in 1689: Some Additions and Corrections Erwin J. O. Kompanje Department of Neurological Surgery, Erasmus Medical Center Rotterdam, the Netherlands he surgical separation of a pair of conjoined twins in Curiosa sive Ephemeridum Medico-Physicarum Tthe year 1689 by Johannes Fatio was the subject of Germanicarum Academiae Imperialis Leopoldinae a recent article in this journal. The reference used as Naturae Curiosorum (König 1689; Zwinger 1690). publication of the case was Fatio’s book, Der Arzney These two articles must be considered as the two ear- Doctor, Helvetisch-Vernüftige Wehe-Mutter, published liest sources concerning this case. The article of König in 1752, although the case was presented in literature (König, 1689) is illustrated with the same engraved by three earlier sources. Two articles were published plate (Figure 1) as Fatio (Figure 3), with some differ- in the Miscellanea Curiosa sive Ephemeridum Medico- ences. König’s plate can be considered as the first Physicarum Germanicarum Academiae Imperialis engraving of the case, leaving Fatio’s plate as a copy Leopoldinae Naturae Curiosorum in 1689 by Emanuel from this engraving. In 1689 Johannes Fatio provided König and another in 1690 by Theodor Zwinger who described and illustrated the case in detail. Besides the details of the case to Zwinger, which formed the these articles, a Flug Blatt was published on the case basis of Zwinger’s article. The girls depicted on the between 1689 and 1695. Fatio copied the engraved engraving were named Elisabet (Elisabetham) and plate in his book from König’s engraving. These two Catherina (Catharinam).
    [Show full text]
  • Separating Conjoined Twins: Legal Reverberations of Jodie and Mary's Predicament
    Loyola of Los Angeles International and Comparative Law Review Volume 24 Number 1 Article 3 1-1-2002 Separating Conjoined Twins: Legal Reverberations of Jodie and Mary's Predicament Jennifer N. Sawday Follow this and additional works at: https://digitalcommons.lmu.edu/ilr Part of the Law Commons Recommended Citation Jennifer N. Sawday, Separating Conjoined Twins: Legal Reverberations of Jodie and Mary's Predicament, 24 Loy. L.A. Int'l & Comp. L. Rev. 65 (2002). Available at: https://digitalcommons.lmu.edu/ilr/vol24/iss1/3 This Notes and Comments is brought to you for free and open access by the Law Reviews at Digital Commons @ Loyola Marymount University and Loyola Law School. It has been accepted for inclusion in Loyola of Los Angeles International and Comparative Law Review by an authorized administrator of Digital Commons@Loyola Marymount University and Loyola Law School. For more information, please contact [email protected]. NOTES AND COMMENTS SEPARATING CONJOINED TWINS: LEGAL REVERBERATIONS OF JODIE AND MARY'S PREDICAMENT On December 10, 2000, a coroner recorded a special verdict for the death of a baby girl in England. 1 The coroner faced an unusual situation - a death from surgery when it was known beforehand the patient was going to die.2 The coroner admitted that all surgeries carry a risk of mortality, but in this case the mortality rate from the surgery was known beforehand to be one hundred percent.3 The special verdict read: "Mary died following surgery separating her from her conjoined twin, which surgery was permitted by an order of the [British] High Court, confirmed by the Court of Appeal."'4 I.
    [Show full text]
  • Multiple Pregnancies
    Learning Objectives Using Ultrasound to Manage Twins After this presentation, the learner will be able to discuss: • Diagnosis and dating in twin pregnancies • Sonographic characteristics that distinguish dichorionic from monochorionic twins • Prenatal ultrasound screening in twins • Complications unique to monochorionic twins Lynn L. Simpson, MD Chief, Division of Maternal Fetal Medicine • Ultrasound surveillance recommendations for twins Columbia University Medical Center, New York Diagnosis and Dating of Twins Importance of Pregnancy Dating • Diagnosis best in the first trimester and dating optimal using crown-rump length • Timing for screening − 20% of first trimester twin pregnancies result in singleton live births and diagnostic testing − “Vanishing twin” is associated with favorable prognosis of surviving twin if dichorionic • Accurate interpretation of twin growth • If discrepancy in dates between the twins, date using the larger twin • Scheduling of twin deliveries − Avoids missing diagnosis of IUGR Types of Twins Determination of Chorionicity • All dizygotic twins are dichorionic • All monochorionic twins are monozygotic • Not all monozygotic twins are monochorionic • Optimal in first trimester − close to 100% accuracy • Incorrect assignment in up to 10% of cases when chorionicity determined in second trimester 2-3 days 3-8 days 8-13 days (28%) (70%) (1%) Lee et al, 2006 Blumenfeld et al, 2014 1 Determination of Chorionicity Intertwin Membrane • Gestational sacs • Amniotic sacs • Placenta number • Intertwin membrane • Gender
    [Show full text]
  • The Siamese Twins, the Bunker Family, and Nineteenth-Century U.S
    American Family, Oriental Curiosity: The Siamese Twins, the Bunker Family, and Nineteenth-Century U.S. Society Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Joseph Andrew Orser Graduate Program in History The Ohio State University 2010 Dissertation Committee: Judy Tzu-Chun Wu, Adviser John Brooke Alan Gallay Copyright by Joseph Andrew Orser 2010 Abstract This dissertation examines the cultural and social spaces that conjoined brothers Chang and Eng Bunker occupied, interrogating the insights their lives offer into nineteenth-century ideas of race, class, gender, and respectability. Chang and Eng were conjoined twins of Chinese descent whose stage name, the Siamese Twins, derived from the country of their birth. The brothers toured the United States as “Oriental” curiosities from 1829 to 1839, and then settled in North Carolina as farmers, becoming slaveholders, marrying white sisters, and eventually fathering twenty-one children between them. In 1849, the twins returned to touring, this time taking two daughters along with them; until their deaths in 1874, Chang and Eng exhibited themselves and their offspring, touring as the Siamese Twins and Children. Through promotional literature, personal correspondence, visual images and newspaper reports, this work traces the evolution of public discourse about the twins and their families, contributing to other considerations of the twins and the course of American Orientalism. This dissertation goes further, however, by introducing early Asian Americans to considerations of the turbulent terrain of class and respectability in the 1830s and 1840s; the increasingly divisive debates over slavery, nativism, and sectionalism; and the tensions of national reunion in the years following the Civil War.
    [Show full text]
  • Introduction
    CLINICAL NEUROSURGERY SUPPLEMENT TO NEUROSURGERY CLINICAL NEUROSURGERY VOLUME 57 VOLUME 57 CLINICAL NEUROSURGERY i Copyright Ó2010 THE CONGRESS OF NEUROLOGICAL SURGEONS All rights reserved. This book is protected by copyright. No part of this book may be reproduced in any form or by any means, including photocopying, or utilized by any information storage or retrieval system without written permission from the copyright holder. Accurate indications, adverse reactions, and dosage schedules or drugs are provided in this book, but it is possible that they may have changed. The reader is urged to review the package information data of the manufacturer of the medications mentioned. Printed in the United States of America (ISSN: 0069-4827) ii CLINICAL NEUROSURGERY Volume 57 Proceedings OF THE CONGRESS OF NEUROLOGICAL SURGEONS New Orleans, Louisiana 2009 iii Preface The 59th Annual Meeting of the Congress of Neurological Surgeons was held in New Orleans, Louisiana, from October 24-29, 2009. Volume 57 of Clinical Neurosurgery represents the official compilation of the invited scientific manuscripts from the plenary sessions, The Presidential Address by Dr David Adelson, and biographic and bibliographic information of the Honored Guest, Dr James T. Rutka. Dr Nathan Selden, Annual Meeting Chairman, and Drs Ali Rezai and Russell Lonser, Scientific Program Chair and Vice Chair respectively, organized a superb meeting which was very well attended with more than 2800 medical attendees. The theme of this year’s Annual Meeting, A Culture of Excellence, exemplified how neurosurgeons define, pursue, and measure excellence in their everyday practice and specialty. Dr David Adelson delivered his inspirational Presidential Address entitled, ‘‘Neurosurgery: A Culture of Excellence,’’ and talked about the concept of ‘‘excellence.’’ This meeting was also a joint meeting with our neurosurgical colleagues from the Neurological Society of India (NSI) and the American Association of South Asian Neurosurgeons (AASAN).
    [Show full text]
  • An Attempt at Dissolution of the Notion of Self a Thesis
    AN ATTEMPT AT DISSOLUTION OF THE NOTION OF SELF A THESIS SUBMITTED TO THE GRADUATE SCHOOL OF SOCIAL SCIENCES OF MIDDLE EAST TECHNICAL UNIVERSITY BY DARIA SUGORAKOVA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN THE DEPARTMENT OF PHILOSOPHY FEBRUARY 2014 Approval of the Graduate School of Social Sciences Prof. Dr. Meliha Altunışık Director I certify that this thesis satisfies all the requirements as a thesis for the degree of Doctor of Philosophy. Prof. Dr. Ahmet İnam Head of Department This is to certify that we have read this thesis and that in our opinion it is fully adequate, in scope and quality, as a thesis for the degree of Doctor of Philosophy. Assoc. Prof. Dr. Erdinç Sayan Supervisor Examining Committee Members Prof. Dr. David Grünberg (METU, Phil) Assoc. Prof. Dr. Erdinç Sayan (METU, Phil) Prof. Dr. Ayhan Sol (METU, Phil) Assoc. Prof. Dr. İskender Taşdelen (Anadolu U., Phil) Assist. Prof. Dr. Hilmi Demir (Bilkent U., Phil) I hereby declare that all information in this document has been obtained and presented in accordance with academic rules and ethical conduct. I also declare that, as required by these rules and conduct, I have fully cited and referenced all material and results that are not original to this work. Name, Last name: Signature: iii ABSTRACT AN ATTEMPT AT DISSOLUTION OF THE NOTION OF SELF Daria Sugorakova Ph.D., Department of Philosophy Supervisor: Assoc. Prof. Dr. Erdinç Sayan February 2014, 139 pages The purpose of this thesis is to provide a plausible approach to the problems of self and personal continuity that arise in various thought experiments and reported extraordinary real-life cases.
    [Show full text]
  • Multiple Births
    Intensive Care Nursery House Staff Manual Multiple Births INTRODUCTION: Multiple gestations are high-risk pregnancies. The rate of monozygotic (MZ) twins is relatively constant at 3-5/1000 deliveries, whereas the dizygotic (DZ) twinning rate varies from 4-50/1000 deliveries and is influenced by race, heredity, maternal age, parity and nutrition. The incidence of multiple births is increasing, partly due to older maternal age and use of assisted reproductive technology. ZYGOSITY and PLACENTATION: MZ twins result when a single ovum is fertilized and subsequently divides into two embryos. The placenta-membrane relationship, determined by timing of the division (Table 1), may be dichorionic-diamnionic (di-di), monochorionic-diamnionic (mono-di), or monochorionic-monoamnionic (mono-mono). Conjoined twins are very rare and occur when the embryo incompletely divides after the 13th day of fertilization. DZ twins develop from two fertilized ova and the placenta is always di-di. Higher-order fetuses may be either MZ or multizygotic. The perinatal mortality rate is closely related to type of placentation (Table) with mono-mono twins at highest risk. Zygosity can be determined for most twins by placentation, gender and blood type. Immunologic studies or DNA analyses can prove zygosity. Table. Zygosity and placentation. Timing of Percent Vascular Perinatal Zygosity division Placentation of twins shunts mortality MZ first 3d di-di 10% very rare low 4th-8th d mono-di 22% very common higher 9th-13th d mono-mono 1% very common highest DZ 2 fertilized ova di-di 66% very rare lowest Note: Di-di placenta can develop with either DZ or MZ.
    [Show full text]
  • Conjoined Twins in West Africa
    Arch Dis Child: first published as 10.1136/adc.55.8.626 on 1 August 1980. Downloaded from Archives of Disease in Childhood, 1980, 55, 626-630 Conjoined twins in West Africa OLUWATOPE A MABOGUNJE AND JAMES H LAWRIE Department ofSurgery, Ahmadu Bello University Hospital, Zaria, Nigeria SUMMARY 12 cases of conjoined twins from West Africa were reported between 1936 and 1978. Eight sets were liveborn and were surgically separated either in local hospitals or abroad. Four were stillborn. Two new cases of stillborn conjoined twins were recently delivered at this hospital. The most common type and the ones most likely to be born alive were the omphalopagi. Surgical separation was successful in 5 cases but the twins separated at Zaria died about a month later. Emergency operations were performed on the pygopagus and ischiopagus, and one member of the former but both of the latter died. The thoracopagus and dicephalus twins were stillborn. However, necropsy findings in one ofthe thoracopagi indicate that surgical separation would have been feasible had the twins been born alive. The internal mechanical factors causing cardiac defects in such twins may be relevant to the study ofthe pathogenesis ofcongenital cardiac malformations. The incidence of conjoined twins in West Africa is twins delivered recently in this hospital-namely, a not precisely known. Studies of such twins contribute thoracopagus and a dicephalus. to the knowledge of embryonic duplication, fetal development, and the mechanism of congenital Material malformations. Noonan' has stressed the relevance All data relating to cases of thoracopagus conjoined twins in the study of the of conjoined twins reported mechanism of cardiac malformations.
    [Show full text]