2. ā¢ The venous drainage of the brain occurs
through a complex system of:
ā¢ Deep and
ā¢ Superficial veins
ā¢ devoid of valves and
ā¢ With thin walls that lack muscular tissue.
ā¢ They pierce the arachnoid mater and
the inner layer of the dura mater to
open into the dural venous sinuses.
3.
4.
5. Superficial and Deep venous system
ā¢ The superficial venous system drains
ā¢ the superficial fifth of the thickness of the cerebrum
ā¢ the deep venous system drains
ā¢ the remaining four fifths of the depth of the cerebrum.
9. Superior cerebral veins : Drains Superolateral and Medial surface
ā¢ Superolaterally
ā¢ On the frontal and parietal lobes
ā¢ venous drainage directed
ā¢ the superior sagittal sinus superiorly or
ā¢ Superficial sylvian vein infeiorly
ā¢ On the temporal lobe,
ā¢ Venous drainage
ā¢ the superficial sylvian vein superiorly or
ā¢ inferiorly toward the dural sinuses below the temporal lobe
ā¢ Known as temporal cerebral veins
ā¢ 8 to 12 in number
10. ā¢ Medially:
ā¢ The medial frontal veins
ā¢ drain the medial surface of the frontal lobe.
ā¢ They can empty either
ā¢ superiorly into the superior sagittal sinus or
ā¢ inferiorly into the inferior sagittal sinus or
ā¢ into the veins that pass around the corpus callosum and drain into the anterior end of the basal vein.
ā¢ The medial parietal veins
ā¢ drain the medial surface of the parietal lobe.
ā¢ They can either empty
ā¢ superiorly into the superior sagittal sinus or
ā¢ course around the splenium of the corpus callosum and drain inferiorly into the vein of Galen or its tributaries.
ā¢ On both lobes, the veins commonly curve over the superior margin of the hemisphere onto
the upper part of the lateral surface where they join the terminal end of the veins from
the lateral surface before emptying into the superior sagittal sinus.
ā¢ Contdā¦
11. ā¢ The posterior pericallosal veins,
ā¢ one on each side,
ā¢ drain the posterior part of the cingulate gyrus and the precuneus and
ā¢ terminate in either
ā¢ the vein of Galen or
ā¢ the internal cerebral vein.
ā¢ The anterior and posterior calcarine veins drain the occipital lobe.
ā¢ The anterior calcarine or internal occipital vein arises
ā¢ drain the anterior portion of the cuneus and lingual gyrus and
ā¢ passes forward to join the posterior pericallosal vein near the splenium
ā¢ terminates in either the internal cerebral vein or the vein of Galen.
ā¢ The posterior calcarine vein
ā¢ drain the area bordering the posterior part of the calcarine fissure and
ā¢ then curves sharply upward on the cuneus to reach the superior sagittal sinus.
12. INFERIOR CEREBRAL VEINS
ā¢ Inferior frontal
ā¢ Anterior : Drains to SSS
ā¢ frontoorbital and frontopolar
ā¢ Posterior : joins deep sylvian vein
ā¢ Olfactory and posterior fronto-orbital
ā¢ Inferior temporal
ā¢ Medial : Empties into basal vein
ā¢ Lateral : drains into the sinuses in the anterolateral part of the tentorium
ā¢ composed of the anterior, middle, and posterior temporobasal veins.
ā¢ The temporobasal veins appear to radiate from the preoccipital notch across the inferior surface of the temporal
lobe.
ā¢ Occipitobasal veins : empties into lateral tentorial sinus
ā¢ anterolaterally toward the preoccipital notch and
ā¢ frequently joins the posterior temporobasal vein before emptying into the lateral tentorial sinus.
16. ā¢The vein of Trolard, or the superior anastomotic vein,
ā¢ is the largest anastomotic vein crossing the lateral surface of the
brain
ā¢ between the superior sagittal sinus and the sylvian fissure.
ā¢ It is more frequently located at the parietal lobe.
19. DEEP VENOUS SYSTEM
ā¢ Deep middle cerebral vein
ā¢ Ventricular group of veins
ā¢ Cisternal group of veins
ā¢ Basal vein of Rosenthal
ā¢ Internal cerebral veins
ā¢ Vein of Galen
20. Deep Middle cerebral vein
ā¢ Lies in the deep part of the sylvian fissure.
ā¢ begins as a vein in the central sulcus of the insula and
ā¢ runs anteriorly and inferiorly toward the limen insulae, where it joins other
insular veins to form a common trunk.
21. Ventricular group of veins
ā¢ The ventricular veins are named mainly according to the location
ā¢ frontal horn veinsāanterior caudate and anterior septal veins;
ā¢ veins of the body of the lateral ventricleā
ā¢ thalamostriate, thalamocaudate, posterior caudate and posterior septal veins;
ā¢ atrium and occipital horn veinsāmedial and lateral atrial veins;
ā¢ temporal horn veinsāinferior ventricular, amygdalar, and transverse hippocampal veins;
ā¢ deep thalamic veinsāanterior and superior thalamic veins;
ā¢ superficial thalamic veinsāanterior, superior, and posterior superficial thalamic veins;
ā¢ choroidal veinsāsuperior and inferior choroidal veins.
24. Basal vein of Rosenthal
ā¢ The basal vein originates below the APS and is divided into three segments :
ā¢ the first, or anterior or striate segment:
ā¢ originates from the junction of the
ā¢ anterior cerebral vein
ā¢ inferior striate,
ā¢ olfactory,
ā¢ fronto-orbital, and
ā¢ deep middle cerebral veins
ā¢ under the APS and runs posteriorly under the optic tract
ā¢ This point corresponds to the most medial (before its termination into the vein of Galen) and usually
most inferior part of the basal vein and
ā¢ laterally indicates the location of the apex of the uncus.
25.
26. ā¢ The second, or middle or peduncular segment,
ā¢ Starts where the peduncular vein joins the basal vein.
ā¢ It runs laterally
ā¢ between uncus and crus cerebri
ā¢ turns around the crus cerebri,
ā¢ generally where the inferior ventricular vein joins the basal vein;
ā¢ Two segment :
ā¢ anterior peduncular and
ā¢ posterior peduncular
ā¢ The main tributaries of the second segment are the peduncular or
interpeduncular, inferior ventricular, inferior choroidal, hippocampal,
and anterior hippocampal veins.
27. ā¢The third, or posterior or posterior mesencephalic segment:
ā¢ runs medially, superiorly, and posteriorly from the lateral mesencephalic sulcus under the
pulvinar of thalamus and penetrate the quadrigeminal cistern.
ā¢ generally drains into the vein of Galen.
ā¢ The main tributaries of the third segment are the:
ā¢ lateral mesencephalic,
ā¢ posterior thalamic,
ā¢ posterior longitudinal hippocampal,
ā¢ medial temporal, and
ā¢ medial occipital veins.
ā¢ Sometimes, the precentral cerebellar, superior vermian, internal occipital, splenial, medial atrial, and
direct lateral and lateral atrial subependymal veins may drain into the third segment of the basal vein.
30. Veins of the Posterior Fossa
ā¢ The veins of the brainstem form a superficial venous plexus deep to the arteries.
ā¢ The posterior fossa venous system is divided into three groups:
ā¢ the anterior or petrosal group,
ā¢ which drains into the superior and inferior petrosal sinuses;
ā¢ the superior or galenic group,
ā¢ which drains into the vein of Galen; and
ā¢ the posterior or tentorial group,
ā¢ which drains into the sinuses near the torcula.
31.
32. THE ANTERIOR OR PETROSAL GROUP
(1) veins related to the anterior aspect of the brainstemā
ā¢ the anterior pontomesencephalic,
ā¢ transverse pontine,
ā¢ anterior medullary, and
ā¢ parenchymal perforating veins;
(2) veins in the wing of the precentral cerebellar fissureāthe brachial veins;
(3) veins on the superior and inferior surfaces of the cerebellar hemispheresā
ā¢ the superior and inferior hemispheric veins, including the veins of the great horizontal fissure;
(4) veins on the
ā¢ cerebellar side (the medial tonsillar vein) and
ā¢ medullary side (the retro-olivary vein and vein of the inferior cerebellar peduncle of the
cerebellomedullary fissure); and
(5) the vein of the lateral recess of the fourth ventricle
33. ā¢ THE SUPERIOR OR GALENIC GROUP
(1) the mesencephalic tributariesā
ā¢ the median anterior pontomesencephalic,
ā¢ lateral anterior pontomesencephalic,
ā¢ lateral pontomesencephalic,
ā¢ lateral mesencephalic, peduncular,
ā¢ posterior mesencephalic, and
ā¢ tectal veinsāand
(2) the cerebellar tributaries
ā¢ the precentral cerebellar vein and its variants and
ā¢ the superior vermian vein.
34. THE POSTERIOR OR TENTORIAL GROUP
ā¢includes the
ā¢ inferior vermian vein
ā¢ its superior and inferior retrotonsillar tributaries
ā¢ the superior and inferior hemispheric veins.
35. Petrosal surface:
Drained by The superior petrosal
vein:
ā¢ formed by the junction of
the transverse pontine and
pontotrigeminal (brachial)
veins and the vein of the
cerebellopontine fissure
(great horizontal fissure).
ā¢ veins running on the petrosal
surface of the cerebellum and
the anterior surface of the
brainstem tend to drain into the
petrosal sinuses via the superior
petrosal vein,
ā¢ except for the veins running on
the surface of the midbrain,
which drain into the galenic
system. 1.Anterior Pontomesencephalic vein 4.Anterior medullary vein
2.Vein of great horizontal fissure
3.Transverse medullary vein
36.
37. Tentorial surface and posterior brainstem drainage
ā¢ The tentorial surface and the posterior aspect of the brainstem are served by
three draining systems:
1. MIDLINE :
ā¢ the midline portion
ā¢ of the cerebellomesencephalic fissure, the veins near the central lobule and culmen
ā¢ (superior vermian veins)
ā¢ The intermediate portion
ā¢ of the wing of the central lobule and the quadrangular lobule
ā¢ (superior hemispheric veins, anterior group)
ā¢ Both of which tend to drain into the vein of Galen.
2. LATERALLY :
ā¢ of the wing of the central, quadrangular, and simple lobules and the tentorial part of the superior
semilunar lobule
ā¢ (superior hemispheric veins, lateral group) tend to
ā¢ drain into the superior petrosal sinus.
38. 3. POSTERIORLY :
ā¢ The veins draining the declive, folium (declival vein), and the intermediate portion of the
simple and superior semilunar lobules
ā¢ (superior hemispheric veins, posterior group)
ā¢ tend to drain into the torcula or transverse or tentorial sinus in the tentorium cerebelli
39. SUBOCCIPITAL SURFACE OF CEREBELLAR HEMISPHERE
ā¢ The suboccipital surface of the cerebellar hemispheres :
ā¢ Drained by inferior hemispheric veins
ā¢ Drainage of the inferior vermis :
ā¢ via the inferior vermian veins,
ā¢ which are formed by the junction of the superior and inferior retrotonsillar veins running in the
retrotonsillar space.
40. INFERIOR ROOF OF 4th VENTRICLE AND LATERAL RECESS
ā¢ drained by the
ā¢ vein of the lateral recess of the fourth ventricle, (aka vein of the cerebellomedullary
fissure)
ā¢ joins the vein of the middle cerebellar peduncle (the vein of the cerebellopontine fissure)
ā¢ and finally empties into the superior petrosal sinus via the superior petrosal vein.
ā¢ It can also anastomose with the retrotonsillar veins at the retrotonsillar space to establish
communication between the petrosal and the tentorial groups of venous drainage.