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Ventricular system: topographic and endoscopic | 3D Neuroanatomy - medical atlas

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Neuroanatomy

Text of Ventricular system: topographic and endoscopic | 3D Neuroanatomy - medical atlas

  • 3D NEUROSURGICAL APPROACHES - ISSN 2254-95953D NEUROSURGICAL APPROACHES - ISSN 2254-9595(HTTP://WWW.3DNEUROANATOMY.COM/CATEGORY/3D-(HTTP://WWW.3DNEUROANATOMY.COM/CATEGORY/3D-

    NEUROSURGICAL-APPROACHES/)NEUROSURGICAL-APPROACHES/)

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    Ventricular system: topographic and endoscopic

    Volumen: 4, Number: 1

    Abarca-Olivas, J (1); Verd-Martnez, I (2); Bartschi, P (1); Gonzlez-Lpez, P (1); Moreno-Lpez, P (1); Lloret-

    Garca, J (1,2).

    MAR2014

    (http://www.3dneuroanatomy.com)

    Navigate to...Navigate to...

  • (1) Department of Neurosurgery, Hospital General Universitario de Alicante, Alicante (Spain)

    (2) Department of Histology and Anatomy , Universidad MIguel Hernndez, San Juan, Alicante (Spain).

    Introduction

    (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven2.jpg)

    The brain ventricles are anatomical interconnected cavities where the cerebral spinal fluid flows through.

    The cerebral ventricular system is composed by the four well known cavities: the two lateral ventricles, the

    third ventricle and the fourth ventricle.

    Each lateral ventricle communicates with the third ventricle through the foramen of Monro and the third

    ventricle communicates with the fourth through the Silvian acqueduct.

    The lateral ventricles and third ventricle approach are particularly difficult because they are deeply

    located, because they are completely surrounded by nervous tissue (among which the motor and sensory

    areas, the visual pathway), because of their curved shape, because of their wide variety in size among

    individuals and because the tiny foramen through which they connect with each other are prone to

    obstruction.

  • (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven3.jpg)The lateral ventricles and the third

    ventricle are in close relationship with a complex arterial irrigation system and particularly with a deep

    venous system draining through the complex Galenic system. In this picture we can see that the transition

    from the lateral ventricle to the third ventricle contains both internal cerebral veins.

    (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven4.jpg)The ventricular system relationship

    with the surrounding nervous structures will determinate the capacity to approach the cerebral lesions as

    well as to explain neurological deficits produced by excessive dilation in hydrocephalus or by primary

    growing masses or by secondary invasion.

    CC: Corpus callosum; CH: Chiasma; CN: caudate nucleus; F: fornix; M: midbrain; T: Thalamus.

    The lateral ventricles

  • (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven6.jpg)Five parts can be described :

    -The frontal horn (orange shade): anterior to the foramen of Monro

    -The body (blue shade): from the foramen of Monro up to the point where the septum pellucidum ends

    and the union point of the corpus callosum and the fornix .

    -The atrium (yellow shade): a triangle limited by the temporal horn and occipital horn and by the body

    -The occipital horn (white shade): a projection to the occipital horn

    -The temporal horn (green shade) : a projection to the temporal lobe.

    Frontal horn

  • (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven8.jpg)In this axial view we see the lateral

    ventricle part anterior to the foramen of Monoro.

    The medial wall is determined by the septum pellucidum (SP)

    The lateral wall is determined by the head of the caudate nucleus (CN)

    The anterior wall is determined by the genu of corpus callosum (GCC)

    (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven9.jpg)Boundaries on this sagittal oblique

    view.

    The lateral wall is determined by the head of the caudate nucleus.

    The anterior wall is determined by the genu of corpus callosum.

    The floor is determined by the rostrum of the corpus callosum.

    The columns of the fornix (CF) are seen in the posterior inferior medial wall

    (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven10.jpg)Coronal view boundaries.

    The roof is determined by by the corpus callosum .(CC)

    The lateral wall is determined by the head of the caudate.(CN)

    The medial view is determmined by the septum pellucidum (SP) and b the columns of the fornix (CF)

    Body of the lateral ventricle

  • (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven12.jpg)Axial view of the floor of the lateral

    ventricle from anterior to posterior:

    Anteriorly we see the foramen of Monro (FM), medialy the body of the fornix (F) and the septum

    pellucidum. On the midline we see the choroid plexus (ChP) that originates from the choroid fissure

    (which separates the fornix from the thalamus , we will see it later in the transition part from lateral to

    third ventricle) and stays lateral to the thalamic fissure (T)

    On the lateral side we see the caudate nucleus, which separates itself from the thalamus through the

    striatal-thalamic groove (ETS) (site where the thalamostriate vein goes through and the stria terminalis)

    (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven13.jpg)Saggital view of the lateral

    ventricle.

    On the medial wall we can see that the superior part of septum pellucidum has been removed and we se

    the fornix (F) that lies inferiorly.

    The lateral wall is composed by the caudate nucleus (CN) lying inside the body of the lateral ventricle.

    The roof is determined by the corpus callosum (CC)

  • (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven14.jpg)In this coronal picture we see the

    roof shaped by the corpus callosum (CC).

    The lateral wall is composed by the head of the caudate nucleus (CN) .

    The medial wall is composed superiorly by septum pellucidum (SP) and inferiorly by the body of the fornix

    (F)

    The floor from medial to lateral we can see the fornix (F) , the choroid fissure(ChF) (which is the choroid

    plexus-ChP-fixing point and is a corridor towards the third ventricle. Pay attention to the internal cerebral

    vein(ICV) ) and finally the thalamus (T).

    Between the thalamus and the caudate nucleus we have the striatal-thalamic groove (ETS) through

    which runs the thalamostriate vein.

    (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven15.jpg)Before describing the endoscopic

    anatomy of the lateral ventricle body, we should explain the trajectory we have to perform with the

    endoscope to get through the foramen of Monro and reach the premammillary body region of the third

    ventricle.

    In this anatomical pi.ece where the right hemisphere has been removed and where an osteotomy at the

    level of the left coronal suture has been performed, we can see the endoscope entry point through the

    Kotchers landmark: 1 cm anterior to the coronal suture and 2 cm lateral to saggital suture.

    The direction of the endoscope on the saggital plane is towards the external acoustic canal (CAE) and on

    the coronal plane is towards the pupila

  • (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven16.jpg)Endoscopic view of the floor of the

    lateral ventricle body. We see the foramen of Monro.

    The limits are :

    Medially and anteriorly : The column of the fornix (CF)

    Laterally : The caudate nucleus and the caudate vein (cv)

    Posteriorly : The choroid plexus pathway from the third ventricle up to the lateral ventricle , the choroid

    fissure origin, the septal vein (SV) and the thalamostriate vein (TEV)

    Inferiorly: the thalamus (T)

    (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven17.jpg)Ventricular body endoscopic picture

    from the foramen of Monro through a 45 optics.

    The floor from left to right , we have the fornix (F), the choroid plexus (ChP), the thalamus (T), the caudate

    nucleus (CN) on the right . We can clearly see the stria terminalis (ST) on the upper right.

    The roof is determined by the corpus callosum (CC).

  • (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven18.jpg)Thalamostriate vein (ETV) pathway

    from the foramen of Monro (FM) through the striatal-thlamic groove , which separates the floor of the

    lateral ventrilcle between the thalamus(T) and the cuadate nucleus(CN)

    Ventricular atrium and occipital horn

    (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven20.jpg)The anatomical landmark to locate

    the ventricular atrium from the cerebral surface is the transverse gyrus .

    We know that the transverse gyrus is guiding us directly to the ventricular atrium (A), which is exposed in

    this picture after a brain slice has been dissected.

  • (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven21.jpg)From this view we can recognize the

    following structures:

    On the medial wall: superiorly lies the forceps major (FM) of the corpus callosum (CC) and inferiorly we

    can see the the calcar avis (CA) which is an intraventricular projection of the calcarine fissure .

    The floor is formed by the collateral trigone (CT), which is an intraventricular projection of the collateral

    sulcus.

    (http://www.3dneuroanatomy.com/wp-content/uploads/2013/12/ven22.jpg)In this picture the choroid plexus is

    elevated and we can see again the calcar avis (CA) on the medial inferior part .

    On the floor ( on a forward projection towards the temporal horn as a collateral eminence (CE)) the

    collateral trigone (CT) and on the anterior atrial wall we can dis