brain

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brain
From the brain and from the brain only, arise our
pleasures, joys, laughter and jests, as well as
our sorrows, pains, grief's and tears.
Hippocrates

• Marilyn Rose

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meninges

• 3 membranes
• Outer- Dura mater- folds house the following
• flax cerebri- cerebral hemisphere
• tentorium cerebelli cerebrum/ cerebellum
• falx cerebelli- cerebellar hemispheres
• Middle- arachnoid- separate from dura by subdural
  space.
• Inner- Pia mater- vascular, adhering to the
  brain- separated from arachnoid by subarachnoid
  space- which is where CSF circulates

3
Brain Bleeds- Hematoma

• Subarachnoid-
• Rupture AVM/ aneurysm
• Worst headache of life
• Between arachnoid and pia
• Epidural
• Traumatic (artery)
• Blood between dura and skull
• Subdural
• Traumatic (vein)
• Shearing/ shaken baby
• Blood between arachnoid and dura

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Subarachnoid
Subdural
Epidural
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tent, falx and cerebellum
Falx cerebelli
Tentorium cerebelli
Tent
Cerebellum Posterior Fossa
http//anatpat.unicamp.br/minDsc78051a.jpg
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ventricular system

• Circulation of CSF though CNS
• 4 cavities
• RT/LT lateral vents- one in each cerebral
  hemisphere separated by cavum septum pellucidum
  (frontal, (atria) occipital, temporal horns)
• Choroid plexus- blood vessel network (bright)
  within lateral ventricles - producing CSF- BEGINS
  POSTERIOR TO 3rd vent
• 3rd opens downward-foramen of Monro- lateral
  thalamus
• 4th opens from cerebral aqueduct- anterior to
  cerebellum and posterior to the pons- CSF goes
  though Magendie (Cisterna magna-spinal cord) and
  Luschka (subarachnoid space)

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Head Ultrasound
3rd vent- blood anterior
Level of 3rd with blood
Normal Choroid posterior to 3rd vent
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http//www.i-am-pregnant.com/images/ventriculomega
ly2.jpg
http//bstr431.biostr.washington.edu/syl/lab2/fig2
04.gif
http//en.academic.ru/pictures/enwiki/71/Gray735.p
ng
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Coronal
Pre and post birth imaging of the brain
http//www.childrenshospital.org/clinicalservices/
Site1867/Images/brain1b.jpg
Sagittal
http//www.justthefactsbaby.com/images/news/2nd-tr
i-25wkBrainweb.jpg
axial
http//www.health.com/health/static/hw/media/medic
al/hw/h9991198.jpg
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Choroid Plexus
Normal or abnormal???
http//www.i-am-pregnant.com/images/Choroid-Plexus
-Cysts-(CPC).jpg
Level of the 3rd ventricle
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cerebrumcortex- gray/white matter

• Rt/Lt hemispheres
• Gyri- folds
• Sulci- groove- central sulcus
• frontal (motor) / parietal lobe (sensory)
• Fissures- deeper grooves-
• longitudnal- superior sagittal sinus/ flax
  (Rt/Lt)
• lateral- Sylvian- frontal/ parietal from temporal
  lobe.
• Corpus callosum- largest bundle of white matter
  w/ in
• cerebrum forms roof of the lateral vents
• connects Rt/ Lt cerebral hemispheres
• 4 parts rostrum, genu, body, splenium

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Corpus Callosum
http//psycnet.apa.org/journals/neu/17/3/images/ne
u_17_3_496_fig1a.gif
http//img.medscape.com/pi/emed/ckb/radiology/3361
39-407730-7910.jpg
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Locate the corpus callosum
www.come-over.to/FAS/corpuscallosum3.jpg
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What is wrong?
http//neurosurgerydallas.com/images/2_1_3_5b.jpg
15
Label the arrows- 1,4, 6, 7
http//www.info-radiologie.ch/brain_mri_coronal_t2
.php
http//upload.wikimedia.org/wikipedia/commons/1/15
/26638.medium-emphasizing-corpus-callosum.png
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Cisterns

• Subarachnoid space- areas at brain base that are
  widened where CSF pools.
• Supracellar cistern- superior to sella- C of W
• Quadrigeminal cistern- posterior to quadrigeminal
  plate of midbrain
• Cisterna magna- lower posterior fossa (largest)

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Cisterns
http//pilgrimagetozion.files.wordpress.com/2009/0
7/cistern.jpg
http//www.aans.org/bulletin/images/Vol17_2_08/Non
enhanced-axial-CT_large.jpg
http//icanhascadherin.files.wordpress.com/2008/09
/happy-face.jpg
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What is wrong?
http//www.scielo.br/img/revistas/anp/v66n3b/a32fi
g01.gif
http//img.medscape.com/pi/emed/ckb/radiology/3361
39-336489-4514.jpg
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Cerebral Lobes

• Cortex divided into 4 lobes
• Frontal- anterior- reason, judgment, vol muscle
• Brocas area for speech- LT frontal gyrus
• Parietal- middle of each hemisphere- post to
  central sulcus- temperature, touch, pain, taste
• Occipital- posterior- visual stimuli from
  thalamus
• Temporal- anterior to occipital-auditory/olfactory
  
• Primary auditory Heschls- auditory info
• Secondary Wernickes comprehension/ speech

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Cerebral lobes
http//space.newscientist.com/data/images/archive/
2222/22224201.jpg
http//www.ispub.com/ispub/ijra/volume_4_number_1_
46/neurological_damage_in_heat_stroke_in_a_child_c
t_mri_and_spect_appearances/heat-fig2b.jpg
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temporal
cerebellum
http//www.imaios.com/var/ezwebin_site/storage/ima
ges/media/images/e-anatomy/brain-mri/en/brain-anat
omy-axial-atlas/4651-1-eng-GB/brain-anatomy-axial-
atlas_imagelarge.jpg
http//www.nature.com/bmt/journal/v39/n4/images/17
05571f1.jpg
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Case study Heat Stroke
The described imaging findings in heat stroke
include early cerebral edema , loss of gray-white
matter differentiation, patchy high signal
intensity of the white matter of cerebral
hemispheres and vascular boundary zone infarcts
and in later stages, diffuse cerebellar atrophy
-severe brain ischemia was the underlying cause
for the neurological involvement in heat stroke
in our patient.
http//images.google.com/imgres?imgurlhttp//www.
ispub.com/ispub/ijra/volume_4_number_1_46/neurolog
ical_damage_in_heat_stroke_in_a_child_ct_mri_and_s
pect_appearances/heat-fig2b.jpgimgrefurlhttp//w
ww.ispub.com/journal/the_internet_journal_of_radio
logy/volume_4_number_1_46/article_printable/neurol
ogical_damage_in_heat_stroke_in_a_child_ct_mri_and
_spect_appearances.htmlusg__MOWFvBWDRgjINv-DxcrF
_mmMfwMh575w477sz41hlenstart3itbs1tb
nidEXEYVfzs4fUVPMtbnh134tbnw111prev/images
3Fq3Dcerebral2Bcortex2Bon2BMRI2Bor2BCT26gb
v3D226hl3Den26sa3DG
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Basal Ganglia

• Subcortical gray matter
• Caudate nucleus- lat to each lat ventricle
• Lentiform nucleus
• Claustrum
• Together they plan and program muscle action.

http//www.brainexplorer.org/brain-images/brain_sl
ice_small.jpg
http//www.biomedcentral.com/content/figures/1471-
2377-6-33-3-l.jpg
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Diencephalon

• Thalamus
• Lg oval grey masses, walls of lat vents, connects
  in mid 3rd vent by massa intermedia
• Hypothalamus
• Inferior to thalamus and posterior to optic
  chiasm, making floor of lat vent- Pituitary Gland
  (hypophysis)- connected by infaundibulum.
• Epithalamus
• Pineal gland- melatonin day/night cycles (can
  Ca)

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Limbic System

• Interconnected fibers adjacent to temporal lobes.
• Emotional aspects of behavior
• Includes hippocampus (short- long term memory
  converter), amygdala, olfactory tracts, fornix,
  cingulate gyrus..
• Brain injury to hippocampus can cause..
• Loss of memory

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Limbic system
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Brainstem

• Major segments are
• Midbrain
• Above the pons, smallest portion of brainstem
• Nerve bundles called cerebral peduncles and
  quadrigeminal plate.
• Surrounds the cerebral aquaduct- which connects
  the 3rd and 4th vents and contains CSF
• Pons
• Oval expansion of brainstem- Bridge- signals to
  spinal cord and cerebral cortex
• Medulla oblongata
• Extends to the spinal cord which exits the
  foramen magnum- heart rate, respiratory rate and
  blood pressure.

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Brainstem
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Cerebellum

• Little brain
• Posterior to brainstem and occupies posterior
  fossa
• Composed of two cerebellar hemispheres with a
  midline Vermis- on the inferior surface lie the
  cerebellar tonsils
• Occassionally they may herniate down the foramen
  magnum..called what????

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Cerebellum
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Cerebellum
Dandy Walker refers to the enlargement of the
posterior fossa secondary to cystic dilatation of
the fourth ventricle as well as hypoplasia of the
cerebellum and vermis.
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What is wrong?
Lt cerebellar abscess
Congenital absence of one cerebellar hemisphere
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Types of brain lesions
PNET-Primitive Neuroectodermal tumors
PNET can occur anywhere in the brain of a child,
although the most common place is in the back of
the brain near the cerebellum. When they occur
here, they are called medulloblastomas. The
symptoms depend on their location in the brain,
but typically the child experiences increased
intracranial pressure. These tumors are fast
growing and often malignant, with occasional
spreading throughout the brain or spinal cord.
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Cerebral Vasculature

• Arteries in the brain are thin and weak.
• high risk for aneurysms and strokes.
• No valves in the veins-blood can flow in either
  direction route for blood-bourne pathogens.
• Dural sinus drains down to the IJs- through the
  superior and inferior sagittal sinus
• Unique capillaries create the Blood Brain Barrier

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Arterial- Blood to Brain

• Paired internal carotid and vertebral arteries.
• Internal carotid becomes- Carotid Siphon
• Anterior cerebral-ACA
• Middle cerebral-MCA
• Circle of Willis Located in Suprasellar cistern-
  cerebral arterial circle- anastomosis of 4 major
  arteries.
• What are they?
• Two vertebral and Two carotids.
• becoming the anterior/posterior cerebral,
  anterior/posterior communicating and internal
  carotids

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Brain Blood Supply
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Circle of Willis
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Venous Blood
Parietal Veins
Superior Sagital Sinus
Confluence of Sinus
Transverse Sinus
Sigmoid Sinus
Internal Jugular Veins
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Which is it?
MCA stroke- frontal/temporal lobe with Wedge
shaped area of decreased density and Slight
midline shift/ mass effect
Aneurysm
AVM
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Cranial Nerves

• 12 cranial
• All but 1st and 2nd arise from the brainstem
• Each nerve corresponds to a function in the body
• Olfactory- smell- superior nasal septum
• Optic-sight-posterior aspect of eye
• Facial-lower pons- control facial muscles
• Vagus-wandering- down to splenic flexure of abd
  and arise from medulla oblongata- enervates many
  abdominal organs

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Cranial Nerves