Manual of Neuroanesthesia

The Essentials

Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor, Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor

• Publisher: CRC Press
• Year: 2017
• eBook ISBN: 9781351650403
• Edition: 1
• Topic: Medicine
• Subtopic: Anesthesiology & Pain Management

This book will provide all the basic details of neuroanaesthesia and how management of different neurosurgical cases may differ. Simple issues such as neurological examination of patient, understanding CT-scan and MRI scans along with anaesthetic management are discussed in simple language, making this book a ready-reckoner. The title provides an insight into all possible aspects of anesthetic management of neurosurgical and commonly encountered neurologic patients. The book also includes chapters related to allied specialities such as critical care, neurology and neuroradiology, making it a complete package.

PART I

Basic principles of neuroanesthesia

1 Anatomical considerations

Gyaninder P. Singh

2 Intracranial pressure

Vasudha Singhal

3 Cerebral perfusion pressure

Nicole Collins and Alaa Abd-Elsayed

4 Brain protection

Judith Dinsmore and Rebecca Campbell

1

Anatomical considerations

GYANINDER P. SINGH

Introduction

Central nervous system

Brain

Spinal cord

Peripheral nervous system

Cranial nerves

Spinal nerves

Cerebrospinal fluid

References

Introduction

The nervous system in humans can be divided into two main parts, the central nervous system and the peripheral nervous system. The brain and spinal cord form the main divisions of the central nervous system (CNS). The cranial and spinal nerves along with their ganglia comprise the peripheral nervous system (Table 1.1). The organization of nervous system is shown in the flow chart.

Central nervous system

Brain

The skull houses the brain and is composed of 28 bones that are mostly paired, but those situated in the midline are unpaired. Internally, the skull cavity is divided into the anterior, middle, and posterior cranial fossa. Vessels and nerves pass in and out of the skull through various foramina (Table 1.2).

The CNS develops from a hollow cylindrical tube called the neural tube. During embryogenesis, the developing brain (i.e., anterior part of the neural tube) is seen to be divided into five continuous parts (telencephalon, diencephalon, mesencephalon, metencephalon, and myelencephalon) from anterior to posterior. As the developing brain enlarges, some regions overgrow the other areas. Thus, some areas get submerged (hidden from the surface) as the brain grows and folds over itself.¹ The cavity of the neural tube is retained as ventricles in the brain and central canal in the spinal cord, which forms a continuous channel filled with cerebrospinal fluid (CSF) (Figure 1.1).

Gross anatomy of the brain

The brain is enclosed in a bony cranial cavity and is surrounded by three layers of meninges: the outer dura mater, the middle arachnoid mater, and the innermost pia mater. The brain is divided into the forebrain, midbrain, and hindbrain² (Figure 1.2).

Forebrain

This is divided into the diencephalon (central part) and the telencephalon or cerebrum. Hidden from the surface of the brain, the diencephalon consists of a dorsal thalamus and a ventral hypothalamus, and the subthalamus and epithalamus as its other divisions. The thalamus is an important station for all sensory systems except the olfactory pathway. The subthalamus consists of the cranial part of red nucleus and the substantia nigra. The epithalamus consists of the habenular nuclei and the pineal gland. The habenular nucleus is the center for integration of the olfactory, visceral, and somatic afferent pathways. The pineal gland does not contain nerve cells but adrenergic sympathetic fibers derived from the superior cervical sympathetic ganglia. The hypothalamus controls and integrates the functions of the autonomic nervous system and the endocrine system and plays a vital role in maintaining body homeostasis.²

Organization of nervous system

Table 1.1 Division of Nervous System and Cavities of the Brain and Spinal Cord

Central nervous system
a. Brain	Cavities
Forebrain (or prosencephalon)
Telencephalon	Right and left lateral ventricles
Cerebral cortex, basal ganglia, limbic system
Diencephalon	Third ventricle
Thalamus, hypothalamus
Midbrain (or mesencephalon)	Cerebral aqueduct
Hindbrain (or rhombencephalon)	Fourth ventricle
Metencephalon
Pons
Cerebellum
Myelencephalon
Medulla oblongata
b. Spinal cord	Central canal
Cervical segments
Thoracic segments
Lumbar segments
Coccygeal segments
Peripheral nervous system
a. Cranial nerves and their ganglia (12 pairs)
12 cranial (I–XII) nerves
b. Spinal nerves and their ganglia (31 pairs)
08 cervical
12 thoracic
05 lumbar
05 sacral
01 coccygeal

Table 1.2 Foramina of Skull and Structure Passing through them

Cranial fossae (bones forming)	Foramina	Structures passing
Anterior cranial fossa (frontal, ethmoid, sphenoid: body and lesser wing) Middle cranial fossa (parietal, temporal, sphenoid: body and greater wing)	Cribriform plate of ethmoid Foramen cecum Anterior ethmoidal canal Posterior ethmoidal canal Optic canal Superior orbital fissure	Olfactory nerve filaments Anterior ethmoidal nerves and vessels Emissary vein Anterior ethmoidal nerve and vessels Posterior ethmoidal nerves and vessels Optic nerve surrounded by meninges Ophthalmic artery nerves: oculomotor, trochlear, abducent, lacrimal, frontal, nasociliary nerve, filaments from internal carotid artery, sympathetic plexus Vessels: orbital branch of middle meningeal artery, recurrent branch of ophthalmic artery, superior ophthalmic vein, inferior ophthalmic vein
	Foramen rotundum	Maxillary nerve
	Foramen ovale	Mandi...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Foreword
• Preface
• Editors
• Contributors
• Part I: Basic Principles Of Neuroanesthesia
• Part II: Examining the Neurosurgical Patient
• Part III: Monitoring the Neurosurgical Patient
• Part IV: Anaesthesia for the Neurosurgical Patient
• Part V: Positioning the Neurosurgical Patient
• Part VI: Fluid Management of the Neurosurgical Patient
• Part VII: Case-Specific Management
• Part VIII: Perioperative Complications In Neurosurgical Patients
• Part IX: Basics of Neuroradiology
• Part X: Basics of Neurointensive Care
• Part XI: Special Considerations
• Appendix: Scales and scores
• Index