brain

Marilyn Rose

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

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

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

Subarachnoid SubduralEpidural

tent, falx and cerebellum

http://anatpat.unicamp.br/minDsc78051a+.jpg Cerebellum= Posterior Fossa

Falx cerebelli

Tentoriumcerebelli

Tent

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)

Head Ultrasound…

3rd vent- blood anterior Level of 3rd with blood

Normal Choroid posterior to 3rd vent

http://bstr431.biostr.washington.edu/syl/lab2/fig204.gif

http://www.i-am-pregnant.com/images/ventriculomegaly2.jpg

http://en.academic.ru/pictures/enwiki/71/Gray735.png

http://www.justthefactsbaby.com/images/news/2nd-tri-25wkBrainweb.jpg

http://www.childrenshospital.org/clinicalservices/Site1867/Images/brain1b.jpg

Pre and post birth imaging of the brain

axial

Coronal

Sagittal

http://www.health.com/health/static/hw/media/medical/hw/h9991198.jpg

Choroid Plexus

http://www.i-am-pregnant.com/images/Choroid-Plexus-Cysts-(CPC).jpg

Level of the 3rd ventricle

Normal or abnormal???

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

Corpus Callosum

http://img.medscape.com/pi/emed/ckb/radiology/336139-407730-7910.jpg

http://psycnet.apa.org/journals/neu/17/3/images/neu_17_3_496_fig1a.gif

Locate the corpus callosum…

www.come-over.to/FAS/corpuscallosum3.jpg

What is wrong?

http://neurosurgerydallas.com/images/2_1_3_5b.jpg

http://upload.wikimedia.org/wikipedia/commons/1/15/26638.medium-emphasizing-corpus-callosum.png

Label the arrows- 1,4, 6, 7…

http://www.info-radiologie.ch/brain_mri_coronal_t2.php

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)

Cisterns

http://pilgrimagetozion.files.wordpress.com/2009/07/cistern.jpg

http://www.aans.org/bulletin/images/Vol17_2_08/Nonenhanced-axial-CT_large.jpg

http://icanhascadherin.files.wordpress.com/2008/09/happy-face.jpg

What is wrong?

http://www.scielo.br/img/revistas/anp/v66n3b/a32fig01.gifhttp://img.medscape.com/pi/emed/ckb/radiology/336139-336489-4514.jpg

Cerebral Lobes Cortex divided into 4 lobes:

Frontal- anterior- reason, judgment, vol muscle Broca’s 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= Heschl’s- auditory info Secondary= Wernicke’s – comprehension/ speech

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_ct_mri_and_spect_appearances/heat-fig2b.jpg

http://www.nature.com/bmt/journal/v39/n4/images/1705571f1.jpg

http://www.imaios.com/var/ezwebin_site/storage/images/media/images/e-anatomy/brain-mri/en/brain-anatomy-axial-atlas/4651-1-eng-GB/brain-anatomy-axial-atlas_imagelarge.jpg

cerebellum

temporal

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?imgurl=http://www.ispub.com/ispub/ijra/volume_4_number_1_46/neurological_damage_in_heat_stroke_in_a_child_ct_mri_and_spect_appearances/heat-fig2b.jpg&imgrefurl=http://www.ispub.com/journal/the_internet_journal_of_radiology/volume_4_number_1_46/article_printable/neurological_damage_in_heat_stroke_in_a_child_ct_mri_and_spect_appearances.html&usg=__MOWFvBWDRgjINv-DxcrF_mmMfwM=&h=575&w=477&sz=41&hl=en&start=3&itbs=1&tbnid=EXEYVfzs4fUVPM:&tbnh=134&tbnw=111&prev=/images%3Fq%3Dcerebral%2Bcortex%2Bon%2BMRI%2Bor%2BCT%26gbv%3D2%26hl%3Den%26sa%3DG

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_slice_small.jpg

http://www.biomedcentral.com/content/figures/1471-2377-6-33-3-l.jpg

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++)

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…

Limbic system

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.

Brainstem

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????

Cerebellum

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.

What is wrong?

Congenital absence of one cerebellar hemisphere

Lt cerebellar abscess

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.

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 IJ’s- through the

superior and inferior sagittal sinus Unique capillaries create the Blood Brain Barrier

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

Brain Blood Supply

Circle of Willis

Venous Blood

Superior Sagital Sinus

Confluence of Sinus

Transverse Sinus

Sigmoid SinusInternal Jugular Veins

Parietal Veins

Which is it?

Aneurysm

AVM

MCA stroke- frontal/temporal lobe withWedge shaped area of decreased density andSlight midline shift/ mass effect

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

Cranial Nerves