3 Cran Vault Dura 12(1)

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Cranial Vault & DuraCranial Vault & DuraCranial Vault & DuraCranial Vault & Dura

Paul F. Aravich, Ph.D.Paul F. Aravich, Ph.D.Medical Gross Anatomy & Embryology 2012Medical Gross Anatomy & Embryology 2012

Department of Pathology & AnatomyGlennan Center for Geriatrics & Gerontology &

Department of Physical Medicine & RehabilitationEastern Virginia Medical School

Norfolk, [email protected]

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Cranial Vault & DuraCranial Vault & Dura

Objectives: Concept map:Objectives: Concept map:Cranial Vault & DuraCranial Vault & Dura

Objectives: Concept map:Objectives: Concept map: The organization of the scalp and its danger zone.The organization of the scalp and its danger zone. Blood supply to the scalpBlood supply to the scalp Openings for the cranial nervesOpenings for the cranial nerves Dura mater & its reflections in the cranial vaultDura mater & its reflections in the cranial vault Dural sinuses & the venous drainage of the brainDural sinuses & the venous drainage of the brain Internal carotid, vertebral & middle meningeal aaInternal carotid, vertebral & middle meningeal aa

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Clinical correlatesClinical correlatesClinical correlatesClinical correlates

Scalp infections & lacerationsScalp infections & lacerations Periorbital Ecchymosis: Black eye vs. Raccoon eyesPeriorbital Ecchymosis: Black eye vs. Raccoon eyes CSF rhinorrhea & CSF otorrhea CSF rhinorrhea & CSF otorrhea Basilar venous plexus & metastatic/infection spreadBasilar venous plexus & metastatic/infection spread Internal carotid artery aneurysm & CN II optic nerveInternal carotid artery aneurysm & CN II optic nerve Fracture of the pterion and type of hemorrhageFracture of the pterion and type of hemorrhage Cavernous sinus thrombusCavernous sinus thrombus

Clinical correlates

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Outline: Outline: Cranial Vault & DuraCranial Vault & DuraOutline: Outline: Cranial Vault & DuraCranial Vault & Dura

ScalpScalp Cranial nerve openingsCranial nerve openings Dura materDura mater Dural sinusesDural sinuses Internal carotid, vertebral & middle meningeal aaInternal carotid, vertebral & middle meningeal aa

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Scalp & its layersScalp & its layers spell S.C.A.L.P.spell S.C.A.L.P.Scalp & its layersScalp & its layers spell S.C.A.L.P.spell S.C.A.L.P.

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Skin

Connective tissue (sub. cut. tissue): vessels/nn

Aponeurosis, epicranial see next slide

Loose connective tissue to allow movement of 1st 3 layers

Pericranium (periostium) tissue lining bone

Scalp: Soft tissue covering cranial vault. Usually has hair.

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Factory/machine accidents entangling hair: Often pull-off scalp proper, causing a scalping injury

Clinical correlate

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Epicranial aponeurosisEpicranial aponeurosis: : for for occipitofrontalis moccipitofrontalis mEpicranial aponeurosisEpicranial aponeurosis: : for for occipitofrontalis moccipitofrontalis m

Aponeurosis = broad flat t.Aponeurosis = broad flat t. Connects 2 bellies of the:Connects 2 bellies of the:

Occipitofrontalis mOccipitofrontalis m A A m of facial expressionm of facial expression, e.g., e.g. frontal frontal belly belly wrinkles foreheadwrinkles forehead & &

-elevates eyelids -elevates eyelids “I can’t believe that”“I can’t believe that”

OccipitalOccipital belly smoothes belly smoothes forehead skin forehead skin

CN VII facial nCN VII facial n

-innervates both bellies-innervates both bellies Fig

. 7.1

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Occipital belly Frontal belly

Occipitofrontalis m

Epicranial aponeurosis

FYI: other mm attach to the epicranial aponeurosis, e.g., superior auricular m, which elevates the auricle (external ear)

FYI. AKA galea aponeurosis

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Scalp Arteries, e.g.Scalp Arteries, e.g.Scalp Arteries, e.g.Scalp Arteries, e.g. Internal carotid aInternal carotid a: 2 brr of: 2 brr of

ophthalmic aophthalmic a Supraorbital a.Supraorbital a. Supratrochlear aSupratrochlear a..

See Orbit lectureSee Orbit lecture

External carotid a. brrExternal carotid a. brr e.g.,e.g.,

Occipital aOccipital a.. Superficial temporal aSuperficial temporal a.. FYI post. auricular a. etc.FYI post. auricular a. etc.

Fig. 7.14 B, p. 537, Grant's Atlas 1999

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Occipital a.

Supratrochlear a.

Supra-orbital a.

Note multiple anastomoses between internal carotid (sup orb/sup

trochlear aa) & external carotid aa (superficial temp/occ. etc. aa)

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Laceration of scalpLaceration of scalp aa: aa:Laceration of scalpLaceration of scalp aa: aa: Bleed like crazyBleed like crazy

Bleed from Bleed from bothboth ends of laceration ends of laceration Due to lots of anastomosesDue to lots of anastomoses FYI. Also, held open by subcutaneous collagen fibersFYI. Also, held open by subcutaneous collagen fibers FYI. Good news: washes away infections better than other sites FYI. Good news: washes away infections better than other sites

Scalp lacerationsScalp lacerations Most common head laceration requiring surgeryMost common head laceration requiring surgery

Clinical correlate

http://www.aafp.org/afp/2008/1015/p945.html

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FYI. For hemostasis (stoppage of bleeding): provide local anesthetic w/ epinephrine & manual pressure; clip/clamp larger aa

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Diploic veins of skullDiploic veins of skull:: Diploic veins of skullDiploic veins of skull::

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They are in the diploe “Di-Plo-E” (AKA spongy layer or cancellous bone) of the calvaria (skullcap). Bone marrow is also in the diploe By contrast, the external & internal surfaces of the calvaria are made of compact (cortical) bone.

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Emissary veinsEmissary veins: connect the skull : connect the skull surface w/ cranial vaultsurface w/ cranial vaultEmissary veinsEmissary veins: connect the skull : connect the skull surface w/ cranial vaultsurface w/ cranial vault

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Emissary v.

They drain into Dural sinus: part of the venous drainage system of brain; discussed later

Diploic v.

Superficial v

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CalvariaCalvaria has has foramina for emissary vvforamina for emissary vv..CalvariaCalvaria has has foramina for emissary vvforamina for emissary vv..

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Emissary v. foramina (present in various skull bones)

FYI. Indentations for arachnoid granulations are bigger: Granulations shunt CSF into dural sinuses

anterior

posterior

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Epicranial aponeurosis:Epicranial aponeurosis:scalp danger zonescalp danger zoneEpicranial aponeurosis:Epicranial aponeurosis:scalp danger zonescalp danger zone Infections Infections deep to epicranial aponeurosisdeep to epicranial aponeurosis

Can gain access to cranial vaultCan gain access to cranial vault Via Emissary veinsVia Emissary veins Scalp infection then becomes intracranial infectionScalp infection then becomes intracranial infection

Infections Infections superficial to epicranial aponeurosissuperficial to epicranial aponeurosis Much less likely to cause intracranial infectionMuch less likely to cause intracranial infection

Clinical correlates

Q. Name another “danger space?” Ans. Retropharyngeal danger space. A fascial plane behind the visceral compartment of the neck

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Boxes: scalp proper. Most of vv. are deep to epicran aponeurosis

Dural sinus

Emissary vEmissary v

The Scalp danger space: deep to epicranial aponeurosis

Scalp epicranial aponeurosis

Superficial v

Diploic v

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Periorbital Ecchymosis Periorbital Ecchymosis ec-key-mosis ec-key-mosis

“P“Peri:” around eyes. “Ecchymosis:” subcutaneous hematomaeri:” around eyes. “Ecchymosis:” subcutaneous hematomaPeriorbital Ecchymosis Periorbital Ecchymosis ec-key-mosis ec-key-mosis

“P“Peri:” around eyes. “Ecchymosis:” subcutaneous hematomaeri:” around eyes. “Ecchymosis:” subcutaneous hematoma

Occipitofrontalis muscle: attachments:Occipitofrontalis muscle: attachments: Posterior attachment: mostly occipital bone Posterior attachment: mostly occipital bone & part of temporal bone & part of temporal bone

-prevents scalp bleeding/infection from going into neck-prevents scalp bleeding/infection from going into neck Lateral attachment: mostly zygomatic archesLateral attachment: mostly zygomatic arches

-prevents scalp bleeding/infection from going laterally-prevents scalp bleeding/infection from going laterally Anterior attachmentAnterior attachment: : skin of forehead/eyelidsskin of forehead/eyelids, , not bonenot bone

Scalp blood Scalp blood can can drain drain into into loose connective tissue of eyelids/root noseloose connective tissue of eyelids/root nose ““Black eye: Black eye: locallocal periorbital bleed; occurs periorbital bleed; occurs w/in hrs post traumaw/in hrs post trauma ““Raccoon Raccoon eyes: eyes:

Occurs Occurs 2-3 days post trauma2-3 days post trauma Always BilateralAlways Bilateral One cause: One cause: bleed from anterior basilar skull Fx can drain into lidsbleed from anterior basilar skull Fx can drain into lids

(i.e., fracture to cribriform plate in floor of anterior cranial fossa)(i.e., fracture to cribriform plate in floor of anterior cranial fossa)

Clinical correlate

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Black eye vs Raccoon eyesBlack eye vs Raccoon eyesBlack eye vs Raccoon eyesBlack eye vs Raccoon eyes

http://en.wikipedia.org/wiki/Black_eye

http://hgimg.com/bookimages/5/2461.1.jpg

Local periorbital subcutaneous hematoma due to bleed from facial trauma

Bilateral subcutaneous hematoma due to bleed from basilar skull fracture

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Scalp lacerationsScalp lacerationsScalp lacerationsScalp lacerations

Lacerations Lacerations superficial to epicranial aponeurosissuperficial to epicranial aponeurosis Do not gape (aponeurosis holds edges close)Do not gape (aponeurosis holds edges close)

Lacerations Lacerations deep to epicranial aponeurosisdeep to epicranial aponeurosis Gape widely; Gape widely; much more bleedingmuch more bleeding

FYI: especially in coronal plane due to opposite pulls of 2 bellies of occipitofront mFYI: especially in coronal plane due to opposite pulls of 2 bellies of occipitofront m

Suture to adjacent epicranial aponeurosisSuture to adjacent epicranial aponeurosis

Clinical correlates

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Fig

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CN III/IV/V1/VI:* superior orbital fissure “count”

V3 trigeminal n. mandibular br.-foramen ovale

middle meningeal a.: foramen spinosum

CN I olfactory-cribriform plate ethmoid bone foramina

*CN III-oculomotor, IV-trochlear, V1 trigeminal-ophthalmic br, VI-abducens

V2 trigeminal n. maxillary br.-foramen rotundum

Review. Cranial vault Openings: CN I –VI

CN II optic-optic canal; w/ ophthalmic a.Lesser wing

Greater wing

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Fig

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4B

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527

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CN VII/VIII-facial/vestibulocochlear: internal auditory meatus on upper posterior face of petrous part of temporal bone

CN IX/X/XI:* jugular foramen on post. lower face of petrous; “count”

CN XII hypoglossal: hypoglossal canal in occipital bone*CN’s: IX-glossopharyngeal, X-vagus,

XI-spinal accessory

Review. Openings: CN VII - XII

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CN’s: cranial vaultCN’s: cranial vaultCN’s: cranial vaultCN’s: cranial vault

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“Superior” view of cranial vault w/ dura; orbital portion of frontal bone removed to show eye

eye eyeI I

II II

III IIIIV hard to see

IV hard to see

VV

VIVI

VII/VIII VII/VIII

IX/X

/XI

IX/X

/XI

cord

XII XII

Hypophyseal fossa

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Middle cranial fossa

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CN II optic n: CN II optic n: nearnearcerebral part ofcerebral part of internal internal carotid acarotid a

CN II optic n: CN II optic n: nearnearcerebral part ofcerebral part of internal internal carotid acarotid a

Aneurysm hereAneurysm here Can affect visionCan affect vision

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“Superior” view of cranial vault w/ dura; orbital portion of frontal bone removed to show eye

eye eye

III III

V

Internal carotid a cerebral segment

Internal carotid a

CN II CN II

cord

XII

Hypophyseal fossa

IX/X

/XI

VII/VIII

VIClinical correlate

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10 CN’s 10 CN’s connect connect w/ w/ brainstembrainstem

10 CN’s 10 CN’s connect connect w/ w/ brainstembrainstem

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Hemisected head

Clivus: mostly made from basilar part of occipital bone*

Squamous (“plate-like”) part of Occipital bone Dotted line:

foramen magnum

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*AKA “basiocciput”

All but CN’s CN I olfactory, & XI spinal acc

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Review. Review. MeningesMeninges: “3 mothers” or : “3 mothers” or coverings for the central nervous systemcoverings for the central nervous systemReview. Review. MeningesMeninges: “3 mothers” or : “3 mothers” or coverings for the central nervous systemcoverings for the central nervous system Tuff mother: Tuff mother: Dura materDura mater

Superficial/outer layerSuperficial/outer layer Adheres directly to inside surface of cranial vaultAdheres directly to inside surface of cranial vault

Spider mother: Spider mother: Arachnoid materArachnoid mater IntermediateIntermediate

Tender mother: Tender mother: Pia materPia mater DeepestDeepest Adheres directly to brain/cordAdheres directly to brain/cord

LeptomeningesLeptomeninges: arachnoid mater + pia mater: arachnoid mater + pia mater

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Dura: Dura: adheres to adheres to the inside surface the inside surface of the cranial vaultof the cranial vault

Dura: Dura: adheres to adheres to the inside surface the inside surface of the cranial vaultof the cranial vault

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“Superior” view of cranial vault w/ orbital portion of frontal bone removed to show eye

eye eye

cord

Hypophyseal fossa

cliv

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Middle cranial fossa e.g., dura

lining basal surface of posterior cranial fossa

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Base of cranial vault w/o dural liningBase of cranial vault w/o dural liningBase of cranial vault w/o dural liningBase of cranial vault w/o dural lining

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Basilar skullAnterior

Posterior

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Review. Cranial vault Meninges: Review. Cranial vault Meninges: 3 “spaces3 “spaces” superficial to deep” superficial to deepReview. Cranial vault Meninges: Review. Cranial vault Meninges: 3 “spaces3 “spaces” superficial to deep” superficial to deep

Epidural: a potential “space” (dura normally adheres to inside of cranial vault)

Subdural: a potential “space” (fluid-filled subarachnoid abuts against it)

Subarachnoid space (actual space)

Brain (also spinal cord, optic n & olfactory n)

bone

Contents. Middle meningeal a (br external carotid a)*dura

arachnoid

pia

Contents 1, e.g., cerebrospinal fluid (CSF)FYI: arachnoid trabecula

*Rupture of middle meningeal a: epidural hematoma

Contents 2: most of the extent of major brain aa Contents 3: most of the extent of major brain vv

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Epidural & Subdural potential spacesEpidural & Subdural potential spacesEpidural & Subdural potential spacesEpidural & Subdural potential spaces

Anterior Posterior

Epidural space superficial to dura

mater

Wooden applicator in subdural space between dura & arachnoid

Arachnoid mater (clear shinny membrane) over vessels/CSF, which are deep

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Brr of middle meningeal a

Lateral view of brain w/ part of dura removed

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Dural repairDural repairDural repairDural repair

Suture/seal after cranial surgerySuture/seal after cranial surgery Fascia lata from pt’s own thighFascia lata from pt’s own thigh

Fascia lata is deep fascia on lateral thighFascia lata is deep fascia on lateral thigh Synthetic duraSynthetic dura Bovine pericardial sacBovine pericardial sac 2011 FDA advisory2011 FDA advisory11 cautioning against certain cautioning against certain

Cadaveric dura transplantsCadaveric dura transplants b/c of risk of fatal prion infection b/c of risk of fatal prion infection Creutzfeldt-Jakob DiseaseCreutzfeldt-Jakob Disease

1http://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/PublicHealthNotifications/ucm241829.htm

Sutures + “Dura Seal”

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Blue pin through arachnoid mater. Note how the arachnoid jumps over sulci (valleys), unlike deeper pia mater, which adheres to brain and penetrates sulci

FYI gyri

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Meninges: 3Meninges: 3 Differences between Cord/Brain Differences between Cord/BrainMeninges: 3Meninges: 3 Differences between Cord/Brain Differences between Cord/Brain

Spinal Cord

vertebrae

duraarachnoid

pia

FYI: arachnoid trabecula

1. Unlike Brain: Actual epidural space exists with cord

2. Unlike Brain: Contains fat & internal vertebral venous plexus

Subarachnoid space (actual space)

3. Unlike Brain: Subdural space is NOT clinically relevant in cord

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Dural tears & basilar skull FxDural tears & basilar skull FxDural tears & basilar skull FxDural tears & basilar skull Fx Trauma- (or surgically) induced torn dura/arachnoidTrauma- (or surgically) induced torn dura/arachnoid CSF rhinorrheaCSF rhinorrhea

CSF (clear fluid) leaks out of CSF (clear fluid) leaks out of nosenose Following Head injury via:Following Head injury via:

Basal skull FxBasal skull Fx of of cribriform plate of ethmoid cribriform plate of ethmoid (i.e., Fx of base of (i.e., Fx of base of anterior cranial fossa) anterior cranial fossa)

CSF otorrheaCSF otorrhea

CSF leaks out of CSF leaks out of earear Following head injury viaFollowing head injury via Basal skull FxBasal skull Fx of of petrous part temporal bone petrous part temporal bone Ruptured ear drum Ruptured ear drum also neededalso needed for CSF for CSF to to leak out of earleak out of ear

Clinical correlates

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3 Dural reflections3 Dural reflections3 Dural reflections3 Dural reflections

Plate 97, Netter

Anterior attachment of falx cerebri: crista galli of ethmoid bone not seen

#1. Falx cerebri: ÷ R/L cerebral hemispheres drops down from

cranial dura like a curtain

In addition to lining the bones of the cranial vault, there are sheets of dura that reflect away from the bone & follow contours of brain

FYI. Falx cerebelli: vertically oriented fold ÷ R/L lobes of cerebellum

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3 Folds of dura, cont.

From, e.g., top of petrous portion of temporal bone and A/P clinoid processes

To falx cerebri, cut here

#3. Diaphragma sellae: separates pituitary from brain

#2. Tentorium cerebelli: makes a tent above cerebellum to separate it from cortex

Superior view of cranial vault

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Diaphragma sellae Diaphragma sellae “diaphragm of the saddle”“diaphragm of the saddle”Diaphragma sellae Diaphragma sellae “diaphragm of the saddle”“diaphragm of the saddle”

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“Superior” view of cranial vault w/ orbital portion of frontal bone removed to show eye

eye eye

cord

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Middle cranial fossa

Dotted line: Diaphragma sellae separating pituitary from brain

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Falx cerebri

cerebellumTentorium cerebelli

Hemisected head

Other views

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SFalx cerebri

Tentorium cerebelli running “down hill”

Falx cerebri and tentorium cerebelliFalx cerebri and tentorium cerebelliFalx cerebri and tentorium cerebelliFalx cerebri and tentorium cerebelliBrain cut away at brainstem

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Dural sinusesDural sinusesDural sinusesDural sinuses There are There are 2 layers of dura2 layers of dura

Periosteal layerPeriosteal layer (superficial; against bone) (superficial; against bone) Meningeal layerMeningeal layer (deeper) (deeper)

Layers split to form dural sinusesLayers split to form dural sinusesA dural sinus is, therefore, A dural sinus is, therefore, a tube of duraa tube of dura

2 Functions of Dural sinuses2 Functions of Dural sinuses:: Drain Drain venous bloodvenous blood from brain from brain

-To -To internal jugular vvinternal jugular vv FYI: R is bigger than LFYI: R is bigger than L

Drain Drain cerebral spinal fluid from braincerebral spinal fluid from brain

Dural sinus

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6 Selected dural sinuses6 Selected dural sinuses6 Selected dural sinuses6 Selected dural sinuses Superior sagittal sinusSuperior sagittal sinus Inferior sagittal sinusInferior sagittal sinus Straight sinusStraight sinus Transverse sinusTransverse sinus Sigmoid sinusSigmoid sinus Cavernous sinusCavernous sinus

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Dural sinusesDural sinusesDural sinusesDural sinuses

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Falx cerebriInferior sagittal sinus; in lower part of falx cerebri

Superior sagittal sinus; in upper part of falx cerebri

Straight sinus; in medial part of tentorium cerebelli

Confluence of sinuses

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Transverse sinus: find indentation in occipital bone of dry skull; in tentor. cerebelli

Cavernous sinus -near pituitary gland Sigmoid sinus: find

indentation in occipital bone of dry skull

Straight sinus in tentorium cerebelli

Confluence of sinuses

Dural sinuses, cont.

FYI: superior petrosal sinus: top of petrous ridge

FYI: inferior petrosal sinus: bottom posterior face petrous ridge

pituitary

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Indentations: transverse & sigmoid sinusesIndentations: transverse & sigmoid sinusesIndentations: transverse & sigmoid sinusesIndentations: transverse & sigmoid sinuses

Blue arrow: transverse sinus

Black arrow: sigmoid sinus

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Orange arrow: jugular foramen for IJV

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Green wire traveling in opened superior sagittal sinus on top of falx cerebri

Green wire continuing into opened transverse sinus within tentorium cerebelli

General area of the confluence of sinuses

Occipital sinus deep

Posterior view of brain

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Superior sagittal sinus

Confluence of sinusesTransverse Sinus

Sigmoid Sinus

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Dural sinuses & internal jugular v posterior view

Internal jugular v

angiogram

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Cavernous sinus -near pituitary gland

Cavernous sinus: 3, 4, 51,52,6, int carotid a., & post. ganglionic. SNS on ICA “count” or say “O TOM CAS”

In the wall of the

sinus: CN III, IV, V1 & V2 “O TOM”34

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51 52

Within the sinus itself; the int. carotid artery and CN VI. “CA” plus

sympathetics on the ICA “S.” “O TOM CAS”

6

C

The unusual instance of an artery inside a venous system

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Cavernous sinus: Cavernous sinus: Internal carotid a & CN’s 3,4,5Internal carotid a & CN’s 3,4,511,5,522,6 ,6 “count”“count”Cavernous sinus: Cavernous sinus: Internal carotid a & CN’s 3,4,5Internal carotid a & CN’s 3,4,511,5,522,6 ,6 “count”“count”

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SStick: sup orbital fissure w/ III, IV, V1, VI

Orange: V2 heading for foramen rotundum

Pipe cleaner: internal carotid a w/ post. gang. SNS fibers from sup cerv gang

Sella turcica

A: Paralyze all eye movement: III, IV & VI

Box: Carotid sinus

cliv

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Superior view of the middle cranial fossa

Q: A cavernous sinus thrombus would have what affect on eye movement?

Cavernous sinus also has ophthalmic vv draining into it from orbit

Clinical correlate

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Cavernous Cavernous sinus sinus white boxwhite box

Cavernous Cavernous sinus sinus white boxwhite box

Black circle: hypophyseal fossa

IIII

IIIIII

VI VI VV1/2

Middle fossa

Posterior fossa

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Superior view of the base of the cranial vault

Green wires entering sinus w/ CN III

not seen-IV

ICA* ICA*

*ICA exiting sinus w/ SNS fibers

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Basilar venous plexus

Sits on clivus

Interconnects various sinuses

Also interconnects w/ internal vertebral venous plexus of spine

Allows spread of metastases & infections between brain/spine/trunk

Clinical correlates

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Internal vertebral venous plexusInternal vertebral venous plexus (of Batson):(of Batson): in cord in cord epidural epidural spacespace

Internal vertebral venous plexusInternal vertebral venous plexus (of Batson):(of Batson): in cord in cord epidural epidural spacespace

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Internal vertebral venous plexus allows malignancy/ infection spread between trunk/spine/brain

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Epidural fat

Epidural fat

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Brain: Blood SupplyBrain: Blood SupplyBrain: Blood SupplyBrain: Blood Supply

Fig. 10.2, p. 369, Blumenfeld. Neuroanatomy Through Clinical Cases. Sinauer, 2002

FYI Common carotid aa

FY

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FYI External carotid a

FYI Arch of aorta

Ver

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Internal carotid aInternal carotid a Br common carotid aBr common carotid a Most strokesMost strokes

Vertebral aaVertebral aa 11stst ascending br subclavian a ascending br subclavian a Travel through: Travel through:

--transverse foramina of 1transverse foramina of 1stst 6 cerv 6 cerv vertvert & through& through

--foramen magnumforamen magnum

-make -make basilar abasilar aIn

tern

al c

arot

id a

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Internal carotid arteryInternal carotid artery (red): (red): segmentssegmentsInternal carotid arteryInternal carotid artery (red): (red): segmentssegments

Grant’s Atlas 2005 Fig. 7.23B p. 621

Cervical seg. That part in

the neck. NO brr in neck

Petrous seg. That part inside carotid canal, which is in petrous part of temp bone

Cavernous seg. That part inside cavernous sinus

Cerebral seg

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Slide 4

Internal carotid artery segments. AP MRA (magnetic resonance angiogram). Does not “capture” stationary tissue

Cervical seg.

Petrous seg.

Cavernous seg.

Cerebral seg.

Klioze SD. The Brain. Dept. of Anatomy & Neurobiology & Dept. Radiology, EVMS

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Vertebral aa Vertebral aa dotted linesdotted linesVertebral aa Vertebral aa dotted linesdotted lines

Posterior view of clivus

Div

. Of a

nato

my.

EV

MS

cliv

usVIVI

VV

XI

III III

IXX

VII VIII

XII

Vertebral aa (reflected inferiorly) as they enter foramen magnum

56

Slide 4

Vertebral artery. AP MRA (magnetic resonance angiogram) Does not “capture” stationary tissue

Vertebral aa

ICA

ICA Klioze SD. The

Brain. Dept. of Anatomy & Neurobiology & Dept. Radiology, EVMS

Basilar a

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Middle Middle meningeal ameningeal aMiddle Middle meningeal ameningeal a

Q: A Q: A Fx of the Fx of the pterionpterion will will rupture what a. rupture what a. & cause what & cause what kind of bleed?kind of bleed?

A: A: ant. br ant. br middle middle meningeal ameningeal a; ; epidural bleedepidural bleed

Grant’s Atlas 2005 Fig. 7.12A p. 609

Posterior br of middle

meningeal a

Anterior br of middle meningeal artery is deep to Pterion “H” encircled in black

FYI. A/P brr sometimes called Frontal/Parietal brr

External carotid a

Maxillary a

Middle meningeal a

Clinical correlate

Medial view

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Craniotomy & CranioplastyCraniotomy & CranioplastyCraniotomy & CranioplastyCraniotomy & Cranioplasty CraniotomyCraniotomy: temporary removal of a bone flap: temporary removal of a bone flap

Epidural Video Epidural Video http://www.youtube.com/watch?v=dLMCwGmWvrw&feature=related

Store bone flap in abdominal subcutaneous space orStore bone flap in abdominal subcutaneous space or Store under the epicranial aponeurosis Store under the epicranial aponeurosis see next slide see next slide oror Freeze & store at a bone bankFreeze & store at a bone bank

CranioplastyCranioplasty: repair of damaged skull: repair of damaged skull Replace bone flap or useReplace bone flap or use Plastic implantPlastic implant

http://www.unifesp.br/dneuro/neurociencias/229_revisao.pdf

http://www.medscape.com/viewarticle/472974_4

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Middle meningeal aMiddle meningeal aMiddle meningeal aMiddle meningeal a

Div

. A

nato

my,

EV

MS

Basilar skull

Anterior

Posterior

Enters cranial vault via foramen spinosum in greater wing of sphenoid

Petrous part

temp bone

Foramen ovale

Foramen magnum

Indentation made by post br of middle meningeal a

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Cranial Vault & DuraCranial Vault & Dura

Objectives: Concept map:Objectives: Concept map:Cranial Vault & DuraCranial Vault & Dura

Objectives: Concept map:Objectives: Concept map: The organization of the scalp and its danger zone.The organization of the scalp and its danger zone. Blood supply to the scalpBlood supply to the scalp Openings for the cranial nervesOpenings for the cranial nerves Dura mater & its reflections in the cranial vaultDura mater & its reflections in the cranial vault Dural sinuses & the venous drainage of the brainDural sinuses & the venous drainage of the brain Internal carotid, vertebral & middle meningeal aaInternal carotid, vertebral & middle meningeal aa

3 Cran Vault Dura 12(1)

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