teae003ca8d94addb66aab5-c5d5615aae30db61d1ced35d35f0936c.r32.… · variants at the craniovertebral...

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Transorbital endoscopic

amygdalohippocampectomy

26 April, 2015

Tim Lucas, MD, PhD

Neurosurgery

[email protected]

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Financial DisclosuresNone

Lucas Lab Funding sources

T32

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TEA

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(Cranial) (Cranial)

Range of globe displacement: 4-7 mm

(4 cadaver approaches)

Lucas, et al., in preparation

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(Cranial) (Cranial)

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Distance from lateral orbital rim to lateral aspect of dural exposure:

Range 2.2-2.8 cm (over 4 cadaver approaches)

2

7postopChen et al., 2014

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9

Bony exposure

Anterior view (slight oblique)

Preop Postop

Craniectomy dimensions:

Medial-lateral: 8-14mm

Superior-Inferior: 11-14mm10

(Cranial)

(Lateral)

11 12

3

13

(Cranial)

(Anterior)

14

15

Extent of resection: Axial

Preop Postop

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Language sparing surgery

Sanai, et al., NEJM 2008;358:18-17

n=186 patients

Role for language mapping in dominant

hemisphere surgery

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Essential

language sites

7

13

15

fingers

tongue

index finger

motor

mouth/

tongue

sensory

2

12

13

9

15

tumor

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Limits of Trans Orbital Exposure

Range of medial-lateral exposure:

38-49.9 degrees


Range of rostral-caudal exposure:

60.4-81.5 degrees


22/04/2015

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Rings and Pillars: An Organized Approach to Development and

Variants at the Craniovertebral Junction

Jason Talbott, MD, PhDAssistant Professor in Neuroradiology

San Francisco General Hospital and UCSF Department of Radiology and Biomedical Imaging

introduction anatomy pathologyembryology

ANATOMY

A. NasionB. Tuberculum sellaC. BasionD. OpisthionE. Hard palateF. Anterior arch, atlasG. Posterior arch, atlasH. Odontoid processI. Body of axis

Smoker et al. Childs Nerv Syst (2008), 24:1123-1145

ANATOMY

H. Odontoid processI. Body of axisJ. Jugular tubercleK. Occipital condyleL. Lateral mass, atlas


ANATOMY

BO= Basiocciput

http://bookdome.com/health/anatomy/Anatomy-Human-Skeleton/Cranial-Bones-Part-2.html

EO= Exocciput

ANATOMY

https://my.statdx.com/#anatomyContent;craniocervical_junction_neurohttp://ajs.sagepub.com/content/32/4/1077/F1.expansion

BIOMECHANICAL MODEL

CENTRAL PIVOT: C2 VB Dens Basiocciput

TWO RINGS Foramen magnum

Lateral clivus Exocciput

Atlas

Pang et al. Childs Nerv Syst (2011), 27:253-64

https://my.statdx.com/#anatomyContent;craniocervical_junction_neuro

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EMBRYOLOGY

Dudek and Fix, Embryology, 1998

EMBRYOLOGY

SCEROTOME

C3

C4

C5

C6

C3

C4

C5

VERTEBRAL BODY RESEGMENTATION

Axial Lateral

Proatlas (C0)

O 1

O 2

O 3

O 4

C1

C2

C3

C1

C2

Proatlas Hypocentrum (prochordal bow)

C1 Hypocentrum (prochordal bow)

AXIAL LATERAL

Menezes et al. Neurosurg (2009), 64:945-54

IMAGING

• CT– Thin cut bone algorithm– 3D reformats for complex anomolies

• MRI– Cervicomedullary compression– Vascular compression– Aberrant CSF flow

• Plain Film– Dynamic flexion/extension

CVJ CraniometryChamberlain’s line Midline sagittal Basilar

impression/invagination

Wackenheim’s clivusbaseline

Midline sagittal Cranivertebraldislocation

Clivus-canal angle Midline sagittal “Craniovertebralkyphosis”

Basal angle Midline sagittal Platybasia

Atlanto-occipital joint axis angle

Coronal Occipital condyle hypoplasia

22/04/2015

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CVJ PATHOLOGY

Malformations of Central Pillar

AXIAL component of occipital sclerotomes, proatlas (C0) and C1 Sclerotomes

ODONTOID BASIOCCIPUT

Odontoid hypoplasia

Basiocciput hypoplasia

Os odontoideum Basilar impression

Ossiculumterminale

Basilar kyphosis

Os avis

Bifid dens

Modified from Pang et al. Childs Nerv Syst (2011), 27:253-64

Malformations of Surrounding Rings

LATERAL component and hypochordal bow of proatlas (C0) and C1 re-segmented sclerotomes

PROATLAS (C0) C1 SCLEROTOME

Third occipital condyle

Hypoplastic anterior C1 arch

Hypertrophic occipital condyle

Hypoplastic/aplastic C1 posterior arch

Atlas assimilation Aplasia lateral mass C1

Bifid anterior and posterior C1 arch

Modified from Pang et al. Childs Nerv Syst (2011), 27:253-64

CVJ PATHOLOGY

CENTRAL PILLAR


Axial component of occipital sclerotome, proatlas(C0) and C1 Sclerotomes


Odontoid hypoplasia

Bifid clivus


Ossiculumterminale

Basilar kyphosis

CENTRAL PILLAR

Odontoid Dysgenesis: Aplastic Dens

• Rare• Associated with…

• Spondyloepiphyseal dysplasia• Muccopolysaccharidoses• Metatropic dwarfism

• Associated with C1-C2 instability


Odontoid Dysgenesis: 3 yo with metatropic dysplasia

CENTRAL PILLAR

Odontoid Dysgenesis: Aplastic base of dens

CENTRAL PILLAR


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Odontoid Dysgenesis: Aplastic apical segment of dens

CENTRAL PILLAR


Odontoid Dysgenesis: Os Odontoideum

UCSF Teaching Filehttp://www.physio-pedia.com/Cervical_Instability

CENTRAL PILLAR

• Controversial congenital vsaquired• Likely both

• C1-C2 instability• Flex/extension

• Associated with many syndromes

Odontoid Dysgenesis: Ossiculum terminale persistens

CENTRAL PILLAR


Basiocciput:


Axial component of occipital sclerotome, proatlas(C0) and C1 Sclerotomes


Odontoid hypoplasia



Ossiculumterminale

Basilar kyphosis

Os avis Bifid clivus

Bifid dens

CENTRAL PILLAR

Basiocciput Hypoplasia: Newborn with CHARGE

CENTRAL PILLAR

UCSF Teaching File

Basiocciput Hypoplasia:

• Basilar invagination• CMJ compression• Occipital condyle

hypoplasia commonly associated

CENTRAL PILLAR


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Central Pillar: Basiocciput

Basilar invagination:

• Anterior (short clivus) and posterior (exoccipital) subtypes

• Platybasia• “Kyphotic” clivus-canal angle• Retroflexed dens (anterior)• CMJ compression• Occipital condyle hypoplasia


RINGS


Lateral component and hypochordal bow of proatlas (C0) and C1 resegmented sclerotomes


Atlas assimilation Hypoplastic anterior C1 arch

Occipital condyle hypoplasia



Aplasia lateral mass C1

3rd Occipital condyle


Assimilation of atlas:

• MC anomaly of CVJ (0.1-3% population)

• Anterior, lateral, posterior zones

• C1-C2 instability• Associated with…

• Basilar invagination• Klippel-Feil• Chiari I

UCSF Teaching File

RINGS

Occipital condyle hypoplasia:

RINGS


Occiptal condyle hyperplasia:

RINGS



Lateral component and hypocordal bow of proatlas (C0) and C1 resegmented sclerotomes


Atlas assimilation Hypoplastic anterior C1 arch

Hypoplasticoccipital condyle



Aplasia lateral mass C1


RINGS

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C1 Neural arch hypoplasia:

• Derived from lateral C1 sclerotome

• Partial to complete• Keller type• Usually stable• C1 posterior arch

“rachischisis” common (4% population

RINGS

UCSF Teaching File

Anterior C1 arch hypoplasia:

• Derived from C1 hypchordal bow

• True aplasia very rare

• Varying degrees of C1-C2 instability• Loss of TAL

attachment and dens

RINGS


SYNDROMES

Syndromes associated with CVJ anomolies:

• Down syndrome• Klippel Fiel• Achondroplasia• Mucopolysaccaridoses• Osteogenesis imperfecta


PILLAR AND RINGS


AXIAL component of occipital sclerotomes, proatlas (C0) and C1 Sclerotomes


Odontoid hypoplasia



Ossiculumterminale

Basilar kyphosis

Os avis

Bifid dens


LATERAL component and hypochordal bow of proatlas (C0) and C1 re-segmented sclerotomes


Third occipital condyle

Hypoplastic anterior C1 arch



Atlas assimilation Aplasia lateral mass C1


Conclusion

• Pillar-ring model of CVJ helps classify and conceptualize vast array of pathologies

• Embryology is your friend• Axial sclerotomes Pillar• Lateral sclerotomes Rings • Proatlas is like “C0”

• CT (thin cut with 3D reformats) for bony anomalies

• MRI for associated compressive pathology

REFERENCES

• Smoker et al. Childs Nerv Syst (2008), 24:1123-1145.

• Pang et al. Childs Nerv Syst (2011), 27:253-64.

• Dudek and Fix, Embryology, 1998.

• Menezes et al. Neurosurg (2009), 64:945-54

2/28/15

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Trauma at the Craniovertebral Junc8on: Don’t Lose Your Head

Lubdha M. Shah ASNR 2015

Objec8ves

•  Review anatomy of the craniovertebral junc8on

•  Discuss various trauma8c injuries of the CVJ – Consider the associated injuries

•  Summarize the complimentary role of different imaging modali8es in assessing CVJ injuries

Harris’ Rule of 12 AOD

•  BAI – distance between basion & rostral extension of posterior cor8cal margin of axis

•  3.4 mm (8.7-‐26) •  Higher sensi8vity on radiographs vs. CT

Rojas CA, et al. Reassessment of the Craniocervical Junc>on : Normal Values on CT. AJNR 2007

AOD

•  BDI – distance from most inferior por8on of basion to superior dens

•  5.7 mm (1.4 -‐9.1)

AOD

•  Powers ra8o – ra8o of distance between basion to spinolaminar line of atlas & distance from opisthion to posterior aspect of anterior C1 arch

•  BC/OA •  0.8 mm (0.6-‐1.2) •  Sensi8vity 33-‐60%

2/28/15

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AOD

•  ADI –  Predental space –  1.3 mm (0.6-‐2.4 mm) – Maintained by atlantodental, alar and transverse ligaments

AOD

•  Atlanto-‐occipital interval

•  Congruent through out joint space

•  1.0 mm (0.5-‐1.8)

•  AO disloca8on •  AO subluxa8on •  Hyperextension , lateral flexion, +/-‐ hyperflexion

•  Incompetence of alar ligament, tectorial membrane

•  Type 1 odontoid fx

Atlanto-‐occipital Dissocia8on Injuries

•  3 types (Traynelis) –  Anterior displacement of occiput

–  Longitudinal distrac8on with separa8on of occiput from C1

–  Posterior displacement of occiput with respect to C1

•  Does not address severity of injury

•  Rotatory subluxa8on

Atlanto-‐occipital Dissocia8on Injuries

•  Incidence higher in peds –  Atlanto-‐occipital joint less concave

–  Underdeveloped ligaments

•  High mortality -‐ brain stem injury

•  Injuries of upper cervical nerve roots

•  Vasospasm and dissec8on of vertebral or IC arteries

Atlanto-‐occipital Dissocia8on Injuries Diffusion Tensor Imaging •  Correla8on with white mader integrity •  May offer greater precision in assessing

neurologic deficit over neurologic examina8on alone

ADC dec in SCI pa8ents Hemorrhage greatest decrease, followed by quadriplegia

2/28/15

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Clivus Fracture

•  High-‐energy blunt trauma •  CN deficits, esp. VI and VII •  High mortality: – brainstem trauma – vertebrobasilar occlusion

Occipital Condylar Fracture •  Hi energy blunt trauma with

axial compression, lateral bending or rota8onal injury to alar ligament

•  Collet-‐Sicard syndrome: paralysis of CN 9,10,11,12

•  Type 1 –  Axial loading; ipsi alar ligament

may be compromised, but stability maintained by contra alar ligament & tectorial membrane

Occipital Condylar Fracture Type 2 –  Extends from occipital bone via condyle to enter FM

–  Stability maintained by intact alar ligaments & tectorial membrane

Type 3 Mediated via alar ligament tension Assoc. disrup8on of tectorial membrane & contra. alar ligament may cause instability

Jefferson C1 Fracture •  Axial loading injury •  Fall from height, diving injury

•  Simultaneous disrup8on of anterior & posterior arches of C1 +/-‐ disrup8on of ligaments

Jefferson Fracture •  Stable if transverse ligament is intact

•  Torn transverse ligament –  Combined offset of C1-‐C2 lateral masses >= 6.9 mm

– Widening of atlantoaxial interval >= 6.9 mm

•  Widening of ADI with dynamic maneuvers also suggests transverse ligament injury (not appropriate in acute semng)

2/28/15

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Transverse Ligament Injury

Dickman and Sonntag •  Type 1 – Midsubstance ligamentous injury

–  Surgical treatment •  Type 2 –  Avulsion of ligamentous inser8on

–  Trial of external mobiliza8on, poten8al of osseous helaing

Dickman CA, Sonntag VK. Injuries involving the transverse atlantal ligament: classifica8on and treatment guidelines based upon experience with 39 injuries. Neurosurgery. 1997 Apr;40(4) 886-‐7.

Odontoid Fracture •  Hyperflexion mechanism

–  5-‐15% of cervical spine fxs •  Anderson & D’Alonzo

Classifica8on –  Type 1

•  Upper dens •  Stable, immobiliza8on

–  Type 2 •  Base of dens •  Most common, non-‐union rate 10-‐77%

–  Type 3 •  Body of axis, facets

Roy-‐Camille Classifica8on – Poten8al for Dens Displacement

•  Type 1: Fx line inclined forwards, anterior dens displacement

•  Type 2: Fx line inclined backwards, posterior dens displacement

•  Type 3: Horizontal fracture, dens displaced anterior or posterior

Odontoid Fracture •  STIR commonly used to evaluate

acuity of fractures

•  STIR signal may be decreased or absent in acute dens fractures, par8cularly in elderly

Lensing FD, et al. Reliability of the STIR sequence for acute type II odontoid fractures. AJNR 2014 Aug;35(8):1642-‐6.

Trauma8c Spondylolisthesis

•  AKA Hangman’s Fracture •  Fracture of C2 pars interar8cularis due to hyperextension and distrac8on

•  Dens typically spared •  Extension to transverse foramen à vertebral artery injury

•  Other fx 1/3 of cases

Trauma8c Spondylolisthesis Levine & Edwards Type 1: Nondisplaced fracture thru neural arch

–  Hyperextension, axial load Type 2: Transla8on & angula8on

–  Hyperextension, axial load, rebound flexion

Type 2A: oblique fx with angula8on

–  Flexion, distrac8on Type 3: Posterior arch fx with facet disloca8on, angula8on

–  Flexion, compression

2/28/15

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Atlantoaxial Rotatory Subluxa8on Alar ligament disrup8on, rota8onal angle < 36 degrees and the contact surface between the facets is less than 60%

Atlantoaxial Rotatory Fixa8on Atlantoaxial subluxa8on, disloca8on

–  Fixa8on occurs within normal range of rota8on of C1-‐C2 joint

–  Flexion with rota8on force •  Pediatric pa8ents have

enhanced elas8city of ligaments, horizontally oriented, shallower joint surfaces of lateral masses, incompletely developed neck musculature, larger head-‐body rela8onship

•  Adults with RA, Down Syndrome, Morquio Syndrome and Marfan Syndrome

Atlantoaxial Rotatory Subluxa8on •  Lateral flexion with

contralateral rota8on “Cock-‐Robin”

•  Neural damage, death –  Time between injury &

reduc8on directly correlates with prognosis

–  Irreducible aser 1-‐3 months, requires surgery

–  Tx: trac8on for 6 weeks, analgesics, AA arthrodesis

•  CT and MRI before reduc8on to evaluate for addi8onal spine injuries

Atlantoaxial Rotatory Subluxa8on Fielding and Hawkins Classifica8on •  Type 1: rotatory subluxa8on, NO displacement of atlas (ADI≤ 3 mm) •  Type 2: rotatory subluxa8on with anterior displacement of atlas 3-‐5 mm •  Type 3: rotatory subluxa8on with anterior displacement of atlas > 5 mm •  Type 4: rotatory subluxa8on with posterior displacement of atlas

Summary

•  Review the complex func8onal CVJ anatomy – Key measurements in assessing trauma8c injury

•  Outlined important trauma8c CVJ injuries –  Iden8fied associated injuries

•  Compared different imaging modali8es in assessing CVJ injuries

References •  Levine AM, Edwards CC. The management of trauma8c

spondylolisthesis of the axis. J Bone Joint Surg Am. 1985 Feb;67(2):217-‐26.

•  Fielding JW, Hawkins RJ. Atlanto-‐axial rotatory fixa8on. (Fixed rotatory subluxa8on of the atlanto-‐axial joint). J Bone Joint Surg Am. 1977 Jan;59(1):37-‐44.

•  Prad H, Davies E, King L. Trauma8c injuries of the c1/c2 complex: computed tomographic imaging appearances. Curr Probl Diagn Radiol. 2008 Jan-‐Feb;37(1):26-‐38. Review.

•  Roy-‐Camille R, Saillant G, Judet T, et al (1980) [Factors of severity in the fractures of the odontoid process (author's transl)]. Rev Chir Orthop Reparatrice Appar Mot; 66:183–186. French.

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