Atlas of Regional Anatomy of the Brain Using MRI

(1)

Contents I

J. C. Tamraz, Y. G. Comair

Atlas of Regional Anatomy of the Brain Using MRI

Softcover Edition

(2)

Contents III

1234

J. C. Tamraz, Y. G. Comair

Atlas of

Regional Anatomy of the Brain

Using MRI

With Functional Correlations

Foreword by Hans Otto Lüders

With 458 Figures in 817 Separate Illustrations

123

(3)

IV Contents

Jean C. Tamraz, MD, PhD Professor and Chairman Department of Neuroradiology Hotel-Dieu de France Hospital Saint-Joseph University Beirut, Lebanon

Youssef G. Comair, MD, FRCSC Professor and Chief

Division of Neurosurgery American University of Beirut Consultant Neurosurgeon The Cleveland Clinic Foundation 44122 Cleveland, Ohio, USA

ISBN 3-540-27876-1 Springer-Verlag Berlin Heidelberg New York ISBN 978 3-540-27876-4 Springer-Verlag Berlin Heidelberg New York

Library of Congress Cataloging-in-Publication Data Tamraz, J. C. (Jean Chucri), 1954-

Atlas of regional anatomy of the brain using MRI : with functional correlations / J.C. Tamraz and Y.G. Comair.

p. ; cm.

Includes bibliographical references and index.

ISBN 3540640991 (hardcover; alk. paper) ISBN 3540278761 (softcover; alk. paper) 1. Brain--Anatomy--Atlases. 2. Brain--Magnetic resonance imaging--Atlases. I.

Comair, Y. G. (Youssef G.)

[DNLM: 1. Brain--anatomy & histology--Atlases. 2. Magnetic Resonance Imaging--Atlases. WL 17 T159a 2000]

QM455.T35 2000

611’.81’0222--dc21 99-044535

This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, speciﬁ cally the rights of translation, reprinting, reuse of illustrations, recitations, broadcasting, reproduction on microﬁ lm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer-Verlag. Violations are liable for prosecution under the German Copyright Law.

Springer is part of Springer Science+Business Media http//www.springeronline.com

The use of general descriptive names, trademarks, etc. in this publication does not imply, even in the absence of a speciﬁ c statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.

Product liability: The publishers cannot guarantee the accuracy of any information about dos- age and application contained in this book. In every case the user must check such information by sonsulting the relevant literature.

Cover-Design: Studio Calamar

Typesetting: Verlagsservice Teichmann, Mauer Printed on acid-free paper – 21/3151xq – 5 4 3 2 1

(4)

Contents V

Foreword

The anatomical dissections of Mundini dei Luzzi in 1316, mark the beginning of an era extending over more than 5 centuries in which the study of the brain was limited, almost exclusive1y, to description of its gross anatomy derived from the inspection of gross anatomical specimens. In the 19th century, new techniques like histology and electrical stimu1ation were developed allowing the ﬁ rst correlation studies of cortical anatomy and brain function. Shortly thereafter, the development of recording techniques of evoked potentials and spontaneous brain waves (EEG) further enhanced our understanding of brain function as a function of its anatomical correlation. One major limitation of all these studies was that at that time no technique was available to deﬁ ne the anatomy of the brain without its direct visualization. In other words, precise anatomo- functional correlation studies were only possible in experimental studies in animals, the unusual setting of human craniotomies and by careful clinico-pathological studies. These last studies also shed some light on the functions of structures that had been affected by a pathological process, and in the late 19th century and early 20th century, research efforts of clinical neuroscientists focused on anatomo-functional correlation studies making brain anatomy one of their pillars. However, soon these research techniques reached a limit and, progressively research efforts focused on pathogenesis, therapeutics and the development of clinical diagnostic techniques. Clinicians soon realized that precise knowledge of brain anatomy was not necessarily an essential clinical tool and brain anatomy classes in neuroscience curricula became only of secondary importance.

However, technological advances that had its beginnings in the early 1950’s eventually lead to a reversal of this trend. A pioneer role in this development was played by the French school lead of Talairach and Bancaud. Taking advantage of newly developed imaging techniques, Talairach realized that angiography could be used effectively to deﬁ ne “non-invasively” the sulcal anatomy of the brain. This led to the development of the “Talairach Atlas”, which even today, can be applied practically. Equally important, however, was the collaboration of Talairach with Bancaud that established functional correlations of the anatomical studies of Talairach. These pioneer studies of Talairach and Bancaud certainly led to signiﬁ - cant contributions of our understanding of human anatomy and its physiological correlates. Unfortunately, the studies had only a limited impact in the general clinical neurosciences since they were only applicable to a very selected number of patients.

Recent neuroimaging developments, particularly high resolution MRI, provided the tools necessary to make detailed brain anatony available to all neu- roscientist on a routine basis. This availability, and the expanded understanding of human anatomo-neurophysiological correlates, has led to a resurgence of the interest of clinical neurophysiologist in gross human brain anatomy and its functional corre1ates.

Tamraz and Comair’s book on regional anatomy of the human brain using MRI, is certainly a welcome addition that fulﬁ lls our growing need for books

(5)

VI Contents

correlating anatomy, function and MRI. There are two facts that make this book particularly appealing for clinicians. Both authors are busy clinicians who, on a daily basis, apply the information provided in the book to their clinical practice.

This assures that all the information provided has immediate clinical relevance.

In addition, the book is greatly inﬂ uenced by Professor Tamraz and Professor Comair’s exposure to the Paris and Montreal’s schools, respectively, both stress- ing brain anatomy and its relationship to neurophysiology. The immediate clinical practicality of the book and the stress on correlating anatomy and function, make this book a unique and valuable contribution to the clinical neuroscience community, and should become a standard textbook for trainees in the clinical neurosciences. The clinical neurosciences will greatly proﬁ t from the practical approach to gross neuroanatomy, neuroimaging and correlative neurophysi ology offered in this book.

Hans O. Lüders

Chairman and Professor

Department of Neurology

The Cleveland Clinic Foundation

(6)

Contents VII

Preface

Imaging of the human nervous system has traditionally attracted clinicians interested speciﬁ cally in the ﬁ elds of neurology, neurosurgery and radiology.

However, interest has suddenly widened to include neurophysiologists, computer scientists, biophysicists and developers of biomedical technology. Several factors are responsible for this phenomenon. We believe that the most important is the development of magnetic resonance imaging (MR).

Angiography and ventriculography visualized brain cavities and computer tomography offered uni-dimensional views of structures. With MR, however, structures came to life. Suddenly patients could walk out of the machine with an atlas-like image of their brain. This advance revived the interest in correlating morphology with function.

Progress in reformatting techniques has facilitated the study of morphology.

Details of the sulcal and gyral anatomy of the brain and its individual variations can be seen thanks to surface- and volume-rendering techniques that have allowed us to extract the brain out of its envelopes. The functional areas can therefore be readily identiﬁ ed by the trained eye. The core brain structures are visually dissected given the high contrast between gray and white matter.

Activation studies have traditionally been performed by expensive, labor-in- tensive techniques that do not visualize the details of morphology. Functional MR has the capability of combining morphology and function in a process similar to the mapping performed in the operating room by pioneering neurosurgeons who identiﬁ ed eloquent cortical areas.

In less than two decades a remarkable evolution in brain science has occurred and impacted on the diagnosis, natural history and treatment of disease process- es. MR is presently a tool used for diagnosis and treatment.

The purpose of this book is to facilitate the study of brain anatomy by formu- lating a methodological analysis of functionally oriented morphology. Since the study of the human cortex has not received much attention in radiological or neurosurgical atlases, we have devoted a large part of this work to the study of the surface anatomy of the brain. Following an introductory chapter on the gyral and sulcal development and organization, functional areas are studied separately in four chapters, each devoted to essential cortical function. Primary motor cortex, speech, limbic system and vision are discussed individually. In addition to the standard sectioning methods, imaging of functional areas relied on extensive use of 3-D rendering and the introduction of innovative oblique sections displaying the temporalization process of the cerebral surface and core brain structures.

These oblique cuts have the advantage of displaying in few images important cortical areas such as the primary motor-sensory cortex, the speech-related perisylvian areas and the amygdalar-hippocampal memory structures.

In order to appreciate the temporal evolution of brain imaging the ﬁ rst chapter reviews the progression in visual depiction of brain structures from rudimentary to cross-sectional and ﬁ nally to realistic and precise illustrations, reminiscent of the progress in neuroimaging. This introduction is followed by an overview of

ToClaire, Caroline and Eve JC T

ToLiliane, Andréa and Marc Elie YG C

(7)

VIII Contents

the major referential brain systems and a proposal for a sylvian reference plane that is, in our view, the most natural way of studying brain structures in cross section.

The ﬁ nal chapters include three new MR atlases. The ﬁ rst comprises coronal sections acquired perpendicular to the proposed sylvian orientation. This is followed by two oblique approaches acquired along the forniceal plane and the ventricular plane.

The study of brain anatomy stands as a linking factor in the multidisciplinary effort to understand brain function. We hope that this book can contribute to- wards this crucial task.

Jean C. Tamraz Youssef G. Comair

Acknowledgments

It is obvious that this volume could not have been ﬁ nished without the published ﬁ ndings and morphological, functional and imaging materials derived from collaborative works developed over the past 20 years by highly specialized teams in Paris, Montreal and Cleveland.

I am deeply indebted to my mentors in Paris for their invaluable teaching and encourage- ment. They had a profound inﬂ uence on my academic course in neuroanatomy and neuroradiology: Professors André Delmas, Chairman of Anatomy at the Institut d’Anatomie;

Emmanuel A. Cabanis, Head of Neuroradiology at the Centre Hospitalier National d’Ophtal- mologie des Quinze-Vingts who trained me in neuroradiology; and Roger Saban, Honorary Professor at the Museum National d’Histoire Naturelle, who introduced me to the fi elds of comparative anatomy and anthropology. The anatomical material included is part of a pre- vious work developed under the leadership of E.A. Cabanis at the Institut d’Anatomie, and the primate brains and teratologic specimens are derived from the historical collections obtained from the Laboratory of Comparative Anatomy of the Museum in Paris. I would also like to express my deep gratitude to Professor Alex Coblentz, Director of the Centre Uni- versitaire Scientifi que et Biomédical des Saints-Pères, for his major support and counseling, and to Professors Georges Salamon, Ugo Salvolini, Henri Duvernoy, Marie-Germaine Bousser and Olivier Lyon-Caen who greatly contributed to our training in the fi elds of neuroimaging, neuroanatomy and clinical neurological sciences. Finally, I am extremely grateful for the collaborative work of Dr. Claire Outin-Tamraz at Trad Hospital, who provided us with part of the MR material to complete this book, and I have also benefi ted in the last few years from discussions at Hôtel-Dieu de France with my colleagues in the Departments of Neuroscience

and Imaging. JCT

Essential contributions to human brain morphology, function and structural organization were made by successive generations of functional neurosurgeons. I was fortunate enough to train at the Montreal Neurological Institute, where some of these essential advances were made. It was a pleasure to train under Professor André Olivier, a master neurosurgeon and anatomist. Long before MR allowed us to see sulcal and gyral anatomy in vivo, Professor Olivier’s teaching of stereoangiography made these structures visible and allowed us to comprehend the complex three-dimensional anatomy of the structures and the vari- ous pathologies that were subsequently dealt with in the operating room. The unique milieu of the Montreal Neurological Institute and the close collaboration between neuroradiology and neurosurgery was a model followed in this book. The content of this book stems from a desire to apply brain anatomy to our clinical practice. At the Cleveland Clinic Foundation, I was priviledged to be associated with Professor Hans Lüders. Our frequent discussions and his profound knowledge of applied electrophysiology and functional localization encouraged us to go ahead with this project. Finally, I am particularly indebted to my colleagues in the epilepsy and neuroradiology programs in Montreal and Cleveland, in particular, Professors Romeo Ethier, Denis Melanson and Paul Ruggieri. YGC

The authors express their sincere gratitude to the publisher, Springer-Verlag, especially Dr.

Ute Heilmann and her co-workers, Mrs. Wilma Mc Hugh, Dr. Catherine Ovitt and Mr. Kurt Tei- chmann, for their help and unfailing patience during the preparation and publication of this atlas.

(8)

Contents IX

1 Historical Review of Cross-Sectional Anatomy of the Brain . . . 1

2 Cephalic Reference Lines Suitable for Neuroimaging. . . 11

I Cranial Reference Lines and Planes. . . 11

A Historical Background and Overview . . . 11

B The Need for a Consensus . . . 12

C Classiﬁ cation of the Cephalic Reference Planes . . . 13

D The Choice of a Nomenclature . . . 13

II Brain Horizontal Reference Lines and Planes . . . 13

A The Bicommissural Reference Plane. . . 14

1 Biometric Data . . . 15

2 Anatomic and Imaging Correlations. . . 17

B The Delmas and Pertuiset Reference Plane. . . 22

2 Topometric Findings . . . 22

C The Neuro-ocular Plane . . . 24

2 Topometric and Biometric Findings . . . 27

D The Callosal Plane . . . 28

E The Chiasmatico-Commissural Plane . . . 29

1 Biometric Findings. . . 29

F Anatomic and Physiologic Reference Planes. . . 35

1 The “Plan Vestibulaire Horizontal” . . . 38

2 The “Plan des Axes Orbitaires” . . . 38

III Brain Vertical Reference Lines and Planes . . . 39

A The Anterior Commissure-Mamillary Planes . . . 39

1 The Commissuro-Mamillary Reference Line. . . 39

2 The Commissuro-Mamillary Plane . . . 40

B The Commissural-Obex Reference Plane . . . 41

1 Biometric Findings. . . 41

References . . . 48

3 Brain Cortical Mantle, Ventricles and White Matter Core . . . 51

I Historical Notes and Landmarks . . . 51

II Cytoarchitecture and Brain Mapping . . . 51

A Gross Morphology and Fissural Patterns of the Brain . . . 56

Contents

(9)

X Contents

1 Gross Morphology . . . 56

2 Brain Sulcation: Classiﬁ cations . . . 57

3 Sulcal and Gyral Anatomy . . . 57

B The Lateral Surface of the Cerebral Hemisphere . . . 57

1 Lateral Fissure of Sylvius . . . 57

2 Central Sulcus (Rolando) . . . 69

3 Inferior Frontal Sulcus. . . 74

4 Superior Frontal Sulcus . . . 74

5 Precentral Sulcus . . . 74

6 The Intraparietal Sulcus . . . 74

7 Superior Temporal Sulcus . . . 78

8 Frontomarginal Sulcus . . . 78

C Gyri of the Lateral Surface of the Cerebral Hemisphere. . . 78

1 The Frontal Lobe . . . 78

a Inferior Frontal Gyrus . . . 78

b Middle Frontal Gyrus. . . 78

c Superior Frontal Gyrus . . . 80

d Precentral Gyrus . . . 80

2 The Parietal Lobe . . . 80

a Postcentral Gyrus . . . 80

b Inferior Parietal Gyri . . . 80

c Superior Parietal Gyrus . . . 81

3 The Temporal Lobe . . . 81

a Superior Temporal Gyrus . . . 81

b Middle Temporal Gyrus. . . 81

c Inferior Temporal Gyrus . . . 81

4 The Occipital Lobe . . . 81

5 The Insula of Reil . . . 83

D The Mesial Surface of the Cerebral Hemisphere . . . 83

1 Cingulate Sulcus . . . 86

2 Parieto-occipital Sulcus . . . 86

3 Calcarine Sulcus . . . 86

4 Rostral Sulci . . . 86

5 Gyri of the Mesial Surface of the Cerebral Hemisphere . . . 86

a The Gyrus Rectus . . . 86

b The Cingulate Gyrus . . . 87

c The Medial Frontal Gyrus . . . 91

d The Paracentral Lobule . . . 91

e The Precuneus. . . 91

f The Cuneus . . . 92

g The Lingual Gyrus . . . 93

E The Basal Surface of the Cerebral Hemisphere . . . 93

1 The Frontal Orbital Lobe . . . 93

a Olfactory Sulcus and Gyrus Rectus . . . 93

b Orbital or Orbitofrontal Sulci and Gyri . . . 93

2 The Temporal Basal Lobe . . . 93

a Collateral Sulcus and Parahippocampal Gyrus . . . 93

b Occipitotemporal Sulcus and Fusiform Gyrus . . . 96

F White Matter Core and Major Association Tracts . . . 96

III Vascular Supply of the Brain. . . 101

A The Arterial Supply of the Brain . . . 101

1 The Internal Carotid Artery . . . 101

(10)

Contents XI

a The Ophthalmic Artery . . . 102

b The Posterior Communicating Artery . . . 102

c The Anterior Choroidal Artery. . . 103

d The Anterior Cerebral Artery . . . 103

e The Middle Cerebral Artery . . . 105

2 The Arterial Circle of Willis . . . 105

B Vascular Supply of the Posterior Fossa . . . 110

1 The Posterior Inferior Cerebellar Artery . . . 110

2 The Anterior Inferior Cerebellar Artery. . . 111

3 The Superior Cerebellar Artery . . . 111

C The Cerebral Venous System . . . 111

References . . . 113

4 Central Region and Motor Cortex . . . 117

I Introduction. . . 117

II Embryology of the Sensorimotor Cortex . . . 117

III Morphology and Imaging . . . 117

A The Central Sulcus. . . 117

B The Precentral Sulcus . . . 120

C The Postcentral Sulcus . . . 121

D Topographical and Functional Anatomy and Imaging . . . 121

1 The Primary Sensorimotor Cortex or Central Cortex . . . 121

a The Primary Motor Cortex or Precentral Gyrus . . . 122

b The Postcentral Gyrus . . . 125

c Motor and Sensory Representation in the Primary Sensorimotor Cortex . . . 125

2 The Premotor Cortex . . . 126

3 The Supplementary Motor Area . . . 128

V The Pyramidal Tract. . . 129

VI Vascular Supply of the Sensorimotor Cortex . . . 133

A Arterial Supply of the Sensorimotor Cortex . . . 133

1 Arterial Supply of the Lateral Aspect of the Hemisphere . . . 133

2 Arterial Supply to the Mesial Aspect of the Hemisphere . . . 134

B Venous Drainage of the Sensorimotor Cortex . . . 134

1 The Lateral Venous Drainage System . . . 134

2 The Mesial Venous Drainage System . . . 135

VII Imaging Approaches for the Localization of the Central Sulcus . . . 135

References . . . .136

5 Perisylvian Cognitive Region. . . 139

I The Lateral Fissure and the Perisylvian Opercula. . . 139

II The Insula of Reil . . . 139

A The Preinsular Area. . . 139

B The Insular Lobe . . . 139

C The Anatomic Relationships of the Insula. . . 142

D Vascular Relationships of the Insula. . . 144

(11)

XII Contents

E Function of the Insula. . . 145

III The Anterior Speech Region . . . 145

A Sulcal Anatomy of the Anterior Speech Region . . . 146

1 The Horizontal Ramus . . . 146

2 The Vertical Ramus . . . 146

3 The Inferior Precentral Sulcus . . . 149

B Gyral Anatomy of the Anterior Speech Region. . . 149

1 The Pars Triangularis . . . 149

2 The Pars Opercularis . . . 149

IV The Posterior Speech Area . . . 150

A Sulcal Anatomy of the Posterior Speech Area. . . 151

1 The Third Segment of the Lateral Fissure . . . 151

2 The Inferior Parietal Sulci. . . 152

3 Posterior Extent of the Parallel Sulcus . . . 152

B Gyral Anatomy of the Posterior Speech Area . . . 153

1 Anatomy of Heschl’s Gyrus . . . 153

2 Anatomy of the Temporal Planum . . . 156

3 Imaging of the Posterior Speech Area . . . 156

V The Cerebral Asymmetries . . . 156

6 Limbic Lobe and Mesial Temporal Region . . . 161

I The Limbic Lobe or “Grand Lobe Limbique”. . . 161

A Morphology and Topographical Anatomy. . . 161

B Imaging of the Limbic Lobe. . . 161

1 The “Forniceal Plane” . . . 163

II Anatomy of the Mesial Temporal Region . . . 163

A The Temporal Polar Cortex . . . 163

B The Entorhinal Area . . . 166

C The Perirhinal Area . . . 166

D The Amygdala. . . 168

1 Morphology, Topographical Anatomy and Imaging of the Amygdala . . . 168

a The Basolateral Group of Nuclei . . . 168

b The Corticomedial Group of Nuclei . . . 169

c The Central Group of Nuclei . . . 170

d Boundaries of the Amygdaloid Bodies . . . 170

2 Functional and Clinical Considerations . . . 171

3 Clinical Considerations and Targeting . . . 171

E The Hippocampal Formation . . . 172

1 Embryology . . . 172

The Choroid Plexus, Tela, Taenia, and Lamina Afﬁ xa . . . 173

2 Morphology and Imaging . . . 173

3 Anatomy of the Hippocampal Formation . . . 174

a The Hippocampus Proper . . . 174

b The Hippocampal Head. . . 174

c The Hippocampal Body . . . 176

d The Hippocampal Tail . . . 176

4 Cytoarchitectonics and Intrinsic Circuitry . . . 177

5 Vascular Supply of the Mesial Temporal Region. . . 179

(12)

Contents XIII

7 Clinical Considerations . . . 181

F The Uncus . . . 181

7 The Basal Forebrain, Diencephalon and Basal Ganglia . . . 185

I Regional Anatomy and Imaging of the Interbrain . . . 185

II The Basal Forebrain and Related Structures . . . 186

A The Septal Region . . . 187

1 Morphology and Topographical Anatomy and Imaging . . . 187

B The Substantia Innominata . . . 190

1 Morphology and Topographical Anatomy and Imaging . . . 190

2 Functional and Clinical Considerations. . . 191

III The Thalamus . . . 191

A Topographical and Nuclear Organization . . . 193

B Functional Aspects and Clinical Considerations . . . 199

The Thalamic Radiations . . . 199

C The Vascular Supply to the Thalamus . . . 200

IV The Epithalamus . . . 200

A The Pineal Gland . . . 200

B The Habenula . . . 200

C The Posterior Commissure. . . 200

V The Hypothalamus . . . 201

A Cytoarchitecture of the Hypothalamus . . . 203

1 The Medial Hypothalamic Zone . . . 203

2 The Lateral Hypothalamic Region. . . 203

B Connections of the Hypothalamus . . . 204

C Functional Aspects and Clinical Considerations . . . 205

D Vascular Supply to the Hypothalamus . . . 205

VI The Subthalamic Region, Subthalamus, or Ventral Thalamus. . . 205

A The Subthalamic Nucleus (Corpus Luysi) . . . 206

1 Morphology and Topographical Anatomy . . . 206

B The Zona Incerta . . . 206

C The Prerubral Field . . . 207

D Vascular Supply to the Subthalamic Region . . . 207

VII The Basal Ganglia . . . 207

A Morphology and Imaging. . . 207

B Topographical Anatomy of the Lenticular Nucleus . . . 209

C Topographical Anatomy of the Caudate Nucleus . . . 209

D Functional Aspects and Clinical Considerations . . . 212

E Functional Neurosurgery . . . 213

F Arterial Supply to the Basal Ganglia . . . 214

VIII The Internal Capsule and Corona Radiata . . . 216

A Gross Morphology and Imaging . . . 216

B Topographical and Functional Anatomy . . . 216

C Arterial Supply to the Internal Capsule . . . 217

(13)

XIV Contents

Synoptical Atlas of Cross-Sectional Anatomy of the Interbrain

Using the Commissural-Obex (PC-OB) Reference Plane . . . 220

From the Genu of Corpus Callosum to the Anterior Commissure . . . 220

From the Anterior Commissure to the PC-OB Reference Plane . . . 222

From the PC-OB Plane to the Splenium of Corpus Callosum . . . 223

Abbreviations. . . 225

8 The Brainstem and Cerebellum. . . 227

II The Brainstem . . . 227

A The Midbrain . . . 228

1 The Rostral Midbrain: Superior Collicular Level . . . 230

2 The Caudal Midbrain: Inferior Collicular Level . . . 230

3 The Midbrain-Diencephalic Junction . . . 231

4 The Red Nuclei and Substantia Nigra. . . 231

a The Red Nucleus: Morphology and Functional Anatomy . . . 231

b Functional and Clinical Considerations . . . 232

c The Substantia Nigra: Morphology and Functional Anatomy . 232 d Functional and Clinical Considerations . . . 234

5 The Cerebral Peduncles or Crus Cerebri . . . 235

B The Pons . . . 236

1 Isthmus Rhombencephali: Upper Pons Level . . . 236

2 The Pons at the Level of the Trigeminal Nerve Root . . . 237

3 The Pons at the Level of the Advent of the Cerebellum. . . 237

C The Medulla Oblongata. . . 238

D The Brainstem Reticular Formation . . . 239

a The Raphe Nuclei or Median Zone . . . 239

b The Medial Reticular Zone . . . 240

c The Lateral Reticular Zone . . . 240

E Vascular Supply to the Brainstem . . . 240

1 At the Midbrain Level . . . 240

2 At the Pontine Level . . . 241

3 At the Medullary Level . . . 241

II The Cerebellum . . . 242

A Developmental Anatomy and Phylogenesis. . . 242

a Structural Organization. . . 243

b The Deep Cerebellar Nuclei . . . 249

3 Vascular Supply to the Cerebellum . . . 252

9 Optic Pathway and Striate Cortex. . . 257

II Short History of the Anatomy of the Visual Pathways . . . 257

III Elements of Ontogenesis, Phylogenesis and Teratology . . . 260

(14)

Contents XV

A Ontogenesis of the Visual System . . . 260

B Phylogenesis of the Anterior Optic Pathways . . . 261

1 The Eyes . . . 261

2 The Optic Nerves . . . 262

3 The Chiasm . . . 262

4 The Lateral Geniculate Body . . . 262

5 The Visual Cortex. . . 262

6 Approach to Evolution Using Magnetic Resonance Imaging . . . . 263

C Elements of Teratology: The Spectrum of Cyclopia. . . 264

IV Morphology and Functional Anatomy and Magnetic Resonance Imaging of the Visual System . . . 268

A Cephalic Orientations and Visual Pathway . . . 268

1 The Neuro-ocular Plane . . . 268

a Anatomical Imaging Correlations . . . 268

b Oculo-orbital Topometry . . . 268

2 The Chiasmatico-Commissural Plane. . . 271

a Anatomic Correlations. . . 271

B The Eyes. . . 273

C The Optic Nerves . . . 273

1 The Intraocular Optic Nerve . . . 273

2 The Intraorbital Optic Nerve . . . 273

3 The Intracanalicular Optic Nerve . . . 274

4 The Intracranial Optic Nerve . . . 280

D The Optic Chiasm . . . 280

E The Optic Tract and the Lateral Geniculate Body . . . 282

F The Geniculocalcarine Tract or Optic Radiation . . . 285

G The Striate Visual Cortex (Area 17) . . . 288

H The Parastriate (Area 18) and Peristriate (Area 19) Cortex . . . 289

I The Superior Colliculi as Related to the Visual System. . . 289

J Vascular Supply to the Visual Pathway. . . 293

V Magnetic Resonance Approach to Neuro-ophthalmological Disorders . . . 293

A The Orbital Region . . . 293

B The Chiasmal Region . . . 294

C The Optic Radiations and Striate Cortex. . . 294

10 Atlas of Cross-Sectional Anatomy of the Brain . . . 299

I Atlas of Cross-Sectional Anatomy Using the Commissural-Obex Reference Plane (Figs. 10.1, 10.2) . . . 299

A From the Frontal Pole to the Genu of the Corpus Callosum (Figs. 10.3–10.10) . . . 299

B From the Genu of the Corpus Callosum to the Anterior Commissure (Figs. 10.11–10.16) . . . 302

C From the Anterior Commissure to the Commissural-Obex Reference Plane (Figs. 10.17–10.24) . . . 303

D From the Commissural-Obex Plane to the Splenium of the Corpus Callosum (Figs. 10.25–10.32) . . . 306

(15)

XVI Contents

E Posterior to the Splenium Toward the Occipital Pole

(Figs. 10.33–10.45) . . . 309 Abbreviations. . . 310 II Atlas of Cross-Sectional Anatomy Using MR Oriented According

to the Ventricular Reference Plane (Figs. 10.46–10.59) . . . 312 III Atlas of Cross-Sectional Anatomy Using the Forniceal Reference

Plane (Figs. 10.60–10.89). . . 316

Subject Index 325