The cerebrospinal venous system (CSVS) consists of the interconnected venous systems of the brain (the cerebral venous system) and the spine (the vertebral venous system).
The anatomic connections between the cerebral and vertebral venous systems was accurately depicted in 1819 by Gilbert Breschet, a French physician later to become Professor of Anatomy at Faculté de médecine de Paris. [1] However, the significance and physiology of this venous complex remained obscure for more than a century, until the seminal work of Oscar Batson. Batson, a Professor of Anatomy at the University of Pennsylvania, in 1940 detailed the anatomy and physiology of the cerebrospinal venous system and its role in the spread of metastases. [2] Batson’s work remains primarily known for its accurate depiction of the vertebral venous system as the route of metastasis of cancer from the prostate to the spine, and the vertebral venous system is often referred to as Batson venous plexus or Batson’s plexus. It is less commonly recognized that Batson’s detailed experiments also demonstrated the direct anatomic connection between the vertebral and cerebral venous system, an anatomical and physiological fact that was later confirmed by others. [3] [4] [5] [6] It was later recognized that the cerebrospinal venous system represents a main route for efflux of venous blood from the brain. [4] [5] [6] Modern imaging methodology, including MR scanning, have detailed the anastomoses of the cerebral and spinal venous systems in the suboccipital region. [7] [8] Batson, and others had recognized that blood flow in the cerebrospinal venous system was bi-directional, a unique feature that was enabled by a general lack of venous valves in these venous plexuses. [9] [10] [11] This bi-directional flow was thought to have physiologic significance with regard to the maintenance of pressure hemostasis within the cranium with changes in posture. [12] [13] The terms “cerebrospinal venous system” and “CSVS” were coined in a 2006 review [14] that has itself been cited in a number of subsequent articles and reviews. [15] [16] [17] [18] [19] [20] [21]
Beginning in 1937 Batson began a series of injection experiments investigating the anatomy and physiology of the cerebrospinal venous system. [2] His carefully documented results demonstrated the continuity of the venous systems of the brain and the spine, as injections of contrast dyes into venous systems feeding into the spinal venous plexus led to the appearance of contrast material in the cerebral veins (Figures 5 and 7, Batson 1940). [2] [9] Batson noted "the extensive filling of the vertebral veins, the superior longitudinal sinus, transverse sinus as well as other dural and cerebral veins" following injection of radiopaque material into a superficial venule in the left breast (Batson 1940, Figure 5, page 143). Subsequent studies by multiple independent authors replicated Batson's findings of the continuity of the cerebral and vertebral venous systems, and the important physiological consequences of this continuity. For example, in 1996, Arnautovic et al., summarizing the results of their own work and that of others, stated: "In addition to confirming that the vertebral venous plexus is a direct continuation of the cranial venous sinuses, our study showed that it is also indirectly connected to these sinuses via the suboccipital cavernous sinus. The vertebral venous plexus is involved in regulating intracranial pressure, transmitting the influence of the respiratory and cardiac pressures to the intracranial compartment and equalizing the pressures within the venous system. [8] ". The continuity of the cerebral and vertebral venous systems was therefore essential to an understanding of both normal physiology, as well as to an understanding of the distribution of tumor metastases, as Batson had so elegantly demonstrated.
It is now recognized that the cerebrospinal venous system represents not only a route for dissemination of metastases, but also a route for dissemination of infection throughout the cerebrospinal axis, in both directions. [17] [22] [23]
In 1957 Batson wrote, ""It seems incredible that a great functional complex of veins would escape recognition as a system until 1940 .... In the first four decades of the last [19th] century, our knowledge of the vertebral veins was developed and then almost forgotten. [9] ". During the past half century, our appreciation of Batson's findings and concepts has grown, expanding beyond his explanation for previously inexplicable routes of tumor metastasis. In 2011, researchers from the Department of Neurological Surgery at Ohio State Medical Center summarized the significance and current understanding of several aspects of the CSVS in their review article: "Today, the vertebral venous plexus is considered part of the cerebrospinal venous system, which is regarded as a unique, large-capacitance, valveless plexiform venous network in which flow is bidirectional that plays an important role in the regulation of intracranial pressure with changes in posture and in venous outflow from the brain, whereas in disease states, it provides a potential route for the spread of tumor, infection, or emboli.". [20]
The cerebrospinal venous system may serve as a route for therapeutic delivery of large molecules to the brain [24] and spinal cord, [25] as discussed: "... the drug enters the brain through the cerebrospinal venous system..."(Sun Sentinel, December 9, 2012, page 21A). [26]
Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates.
Veins are blood vessels in the circulatory system of humans and most other animals that carry blood toward the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart. In the systemic circulation arteries carry oxygenated blood away from the heart, and veins return deoxygenated blood to the heart.
Articles related to anatomy include:
The ventricular system is a set of four interconnected cavities known as cerebral ventricles in the brain. Within each ventricle is a region of choroid plexus which produces the circulating cerebrospinal fluid (CSF). The ventricular system is continuous with the central canal of the spinal cord from the fourth ventricle, allowing for the flow of CSF to circulate.
Pia mater, often referred to as simply the pia, is the delicate innermost layer of the meninges, the membranes surrounding the brain and spinal cord. Pia mater is medieval Latin meaning "tender mother". The other two meningeal membranes are the dura mater and the arachnoid mater. Both the pia and arachnoid mater are derivatives of the neural crest while the dura is derived from embryonic mesoderm. The pia mater is a thin fibrous tissue that is permeable to water and small solutes. The pia mater allows blood vessels to pass through and nourish the brain. The perivascular space between blood vessels and pia mater is proposed to be part of a pseudolymphatic system for the brain. When the pia mater becomes irritated and inflamed the result is meningitis.
In neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous system. The other two meningeal layers are the arachnoid mater and the pia mater. It envelops the arachnoid mater, which is responsible for keeping in the cerebrospinal fluid. It is derived primarily from the neural crest cell population, with postnatal contributions of the paraxial mesoderm.
Cerebral circulation is the movement of blood through a network of cerebral arteries and veins supplying the brain. The rate of cerebral blood flow in an adult human is typically 750 milliliters per minute, or about 15% of cardiac output. Arteries deliver oxygenated blood, glucose and other nutrients to the brain. Veins carry "used or spent" blood back to the heart, to remove carbon dioxide, lactic acid, and other metabolic products. Because the brain would quickly suffer damage from any stoppage in blood supply, the cerebral circulatory system has safeguards including autoregulation of the blood vessels. The failure of these safeguards may result in a stroke. The volume of blood in circulation is called the cerebral blood flow. Sudden intense accelerations change the gravitational forces perceived by bodies and can severely impair cerebral circulation and normal functions to the point of becoming serious life-threatening conditions.
The emissary veins connect the extracranial venous system with the intracranial venous sinuses. They connect the veins outside the cranium to the venous sinuses inside the cranium. They drain from the scalp, through the skull, into the larger meningeal veins and dural venous sinuses.
The arachnoid mater is one of the three meninges, the protective membranes that cover the brain and spinal cord. It is so named because of its resemblance to a spider web. The arachnoid mater is a derivative of the neural crest mesoectoderm in the embryo.
The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica.
The superior sagittal sinus, within the human head, is an unpaired area along the attached margin of the falx cerebri. It allows blood to drain from the lateral aspects of anterior cerebral hemispheres to the confluence of sinuses. Cerebrospinal fluid drains through arachnoid granulations into the superior sagittal sinus and is returned to venous circulation.
A dural arteriovenous fistula (DAVF) or malformation is an abnormal direct connection (fistula) between a meningeal artery and a meningeal vein or dural venous sinus.
The inferior ophthalmic vein is a vein of the orbit that - together with the superior ophthalmic vein - represents the principal drainage system of the orbit. It begins from a venous network in the front of the orbit, then passes backwards through the lower orbit. It drains several structures of the orbit. It may end by splitting into two branches, one draining into the pterygoid venous plexus and the other ultimately into the cavernous sinus.
The condylar canal is a canal in the condyloid fossa of the lateral parts of occipital bone behind the occipital condyle. Resection of the rectus capitis posterior major and minor muscles reveals the bony recess leading to the condylar canal, which is situated posterior and lateral to the occipital condyle. It is immediately superior to the extradural vertebral artery, which makes a loop above the posterior C1 ring to enter the foramen magnum. The anteriomedial wall of the condylar canal thickens to join the foramen magnum rim and connect to the occipital condyle.
The internal vertebral venous plexuses lie within the vertebral canal in the epidural space, and receive tributaries from the bones and from the spinal cord.
In vertebrates, a venous plexus is a normal congregation anywhere in the body of multiple veins.
The Batson venous plexus is a network of valveless veins in the human body that connect the deep pelvic veins and thoracic veins to the internal vertebral venous plexuses. Because of their location and lack of valves, they are believed to provide a route for the spread of cancer metastases. These metastases commonly arise from cancer of the pelvic organs such as the rectum and prostate and may spread to the vertebral column or brain. The plexus is named after anatomist Oscar Vivian Batson, who first described it in 1940. Batson's plexus is part of the Cerebrospinal venous system.
Anterior spinal veins are veins that receive blood from the anterior spinal cord.
The following outline is provided as an overview of and topical guide to human anatomy: