a-049 rc 211 a. brain anatomy made easy

Brain Anatomy Made Easy

TA YousryInstitute of Neurology

National Hospital for Neurology and Neurosurgery

Queen Square

Subdivision of the cortex

Lobes

Gyri Location of primary functional cortex

Sensorimotor

Audition

Vision

Cortical Subdivisions

Surface Lobes Gyri and Sulci Cytoarchitectonic

Surface

Medial Lateral (convexity) Inferior (basal)

Lobes

Current concept

Lobes

Current concept

1) Frontal L 2) Parietal L

3) Temporal L 4) Occipital L

Lobes

Current concept



5) Insula

Lobes

Current concept



5) Insula 6) Limbic L

Lobes

Convexity

Frontal Parietal Temporal Occipital Insula

Lobes

Medial surface

Frontal Parietal Temporal Occipital Limbic

1. Lateral SurfaceFrontal lobe

3+1 Superior frontal

gyrus (F1) Middle (F2) Inferior (F3) Precentral G

(Transverse)

1. Lateral SurfaceTemporal lobe

3+1 Superior temp

gyrus (T1) Middle (T2) Inferior (T3)

Heschl’s gyrus (Transverse G)

1. Lateral Surface

Occipital lobe

3 Superior occip

gyrus (O1) Middle (O2) Inferior (O3)

1. Lateral Surface

Parietal lobe Postcentral G Superior parietal

Lobule (P1) Inferior parietal

Lobule (P2) Supramarginal G Angular G

2. Medial Surface

Frontal lobe Gyrus rectus Sup frontal gyrus Parac. lobule (ant)

Parietal lobe Parac. lobule (post) Precuneus

2. Medial Surface

Occipital lobe Cuneus Lingual gyrus

Limbic lobe Limbic gyrus Intralimbic gyrus

3. Inferior Surface

Frontal lobe Gyrus rectus Orbital gyri

Medial/Lateral/Anterior/Posterior

TP Naidich, Mount Sinai, New York

3. Inferior Surface

Temporal/Occipital lobes Inferior temporal/occipital gyrus (T3/O3) Fusiform gyrus (T4/O4) (lateral

occipito-temporal) Parahippocampal/Lingual gyrus (T5/O5)

(medial occipito-temporal)

Lobes

The subdivisions of the cerebrum are

purely arbitrary and do not correspond

exactly to any known functional

divisionsG. Yasargil

I. Primary Sensorimotor

Cortex

Motor Strip

Functional Organization

Somatotopie (Homunculus)

Precentral G

Postcentral G

Central Region

Components

Precentral gyrus Postcentral gyrus Paracentral lobule Subcentral gyrus

Methods of Identification

Cerebral Landmarks Axial

1. L sign 3. PrCG/Cortex Thickness/SI

2. Knob/Ω/ε 4. Bracket-Moustache-PM Sagittal

1. Medial sagittal (Pars marginalis)2. Knob/Hook3. Lateral sagittal

1st Axial Landmark“L” Sign

Lateral axial (Kido)

SFS—PreCS (88%)

2nd Axial Landmark

“Knob/Ω/ε” Sign

Knob (Yousry)

MHA (Genu medius)

(96%)

(90%) (10%) At SFS-PreCS junction (100% – path; 96% + path)

3rd Axial LandmarkThickness: Gyrus, Cortex - SI

a) Gyral thickness (Naidich)

PrecG > PostCG

(98%)

9.4T


Cortical thickness

3rd Axial Landmark Thickness: Gyrus, Cortex - SI


b) Cortical thicknessGPrec > GPostC

(Meyer 96)

Biega et al. AJNR 06


c) Cortical SICS < Frontal

(Karaarslan 03)

4th Axial LandmarkBracket-Moustache-Pars Marginalis

Medial axial (Naidich)

CS into Pb in 87%

A-028.jpgTP Naidich, New York

PARS MARGINALIS - LOW

TP Naidich, Mount Sinai, NY

PARS MARGINALIS - HIGH


1st Sagittal LandmarkPars Marginalis

Medial sagittal

CS anterior

PM

Notch in

Paracent lob

2nd Sagittal LandmarkKnob/Hook

Hook (91% pathology)

3rd Sagittal Landmark Lateral sagittal (Naidich)

Sylvian fissureAnt horiz rAnt asc rIFSIFG (M)PreCSCS

Recognition System

AXIALAnatomic 1) Knob

2) “L” SFS-PreCS opposite to Knob

3) Moustache/Pars Bracket4) PreCG > PoCG

Recognition System

SAGITTALAnatomic 1) Ant Asc—Horiz Ramus

2) Hook

3) Pars Bracket

II. Primary Auditory Cortex

Auditory pathway

Heschl’s Gyrus

Axial

Course

Anterolateral Landmark

Adhaesio interthalamica

Internal cerebral veins

Heschl’s GyrusSagittal Shape

Omega (medial)Heart (Sulcus intermedius of

Beck) Posterior border

Heschl’s Sulcus

Heschl’s Gyrus

Coronal

ShapeOmega (medial)

Landmark

Tent-like shape of the fornices

V5 ACTIVE

Morosan et al. Neuroimage 2001

Rademacher Neuroimage 2001

SummaryPrimary Audition – Heschl’s gyrusAxial Adhaesio interthalamica

Sagittal Omega—Heart

Coronal Omega

Cytoarchitectonic variations of Te1

III. Primary Visual Cortex

PARIETO-OCCIPITAL CONFIGURATION

LAZY - Y

CALCARINE SULCUS PATTERNS

R L

SINGLE PEAK 38 32

PLATEAU 26 28

ONO ATLAS of the CEREBRAL SULCI 1990


CALCARINE SULCUS PATTERNS

R L

DOUBLE PEAK 16 20

S-SHAPED 12 16

TRIPLE PEAK 8 4ONO ATLAS of the CEREBRAL SULCI 1990 TP Naidich, Mount Sinai, NY

L L

RR


II

Courtesy TP Naidich

Visual Cortex Anatomy

Primary visual cortex (V1) contains visual stria of Genari (striate cortex)

Extrastriate Visual Cortex (V2-V5)

V1 V3 V4 V5

Variability of BA 17

Amunts et al. NeuroImage 2000

SummaryPrimary Vision– Calcarine SulcusSagittal Lazy – Y

Cytoarchitectonic variations of BA 17

Summary

Subdivisions of the cortex

Surfaces 3

Lobes 6

SummarySensorimotor – Central regionAxial 1) Knob

2) SFS-PreCS opposite to Knob

3) Pars Bracket-Moustache4) PreCG > PoCG

SummarySensorimotor – Central regionSagittal 1) Ant Asc—Horiz Ramus

2) Hook

3) Pars Marginalis

SummaryPrimary Audition – Heschl’s gyrusAxial Adhaesio interthalamica

Sagittal Omega—Heart

Coronal Omega

Cytoarchitectonic variations of Te1

Summary

Importance of the surface anatomyAnatomic-functional relationship

a-049 rc 211 a. brain anatomy made easy

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