Neuroanatomy andNeuroanatomy andBrain InjuryBrain Injury

Dennis J. Zgaljardic, Ph.D., ABPP-CN Dennis J. Zgaljardic, Ph.D., ABPP-CN Director, Department of NeuropsychologyDirector, Department of Neuropsychology

Transitional Learning Center Transitional Learning Center Galveston, TXGalveston, TX

The SkullThe Skull

Inflexible protective shell Inflexible protective shell Comprised of several bones; names Comprised of several bones; names

correspond to underlying brain lobescorrespond to underlying brain lobes FrontalFrontal TemporalTemporal ParietalParietal OccipitalOccipital

MeningesMeninges

Three membranes inside the skull that Three membranes inside the skull that provide further protection to the brainprovide further protection to the brain Dura materDura mater

- outside, hard layer (like baseball covering) - outside, hard layer (like baseball covering) Arachnoid materArachnoid mater

- adheres to inner surface of dura; CSF - adheres to inner surface of dura; CSF percolatespercolates

Pia mater – adheres to surface of brainPia mater – adheres to surface of brain

Cerebrospinal FluidCerebrospinal Fluid

Fluid that cushions brain from the skullFluid that cushions brain from the skull Produced in the choroid plexus of the Produced in the choroid plexus of the

lateral ventricleslateral ventricles Circulates in the subarachnoid space and Circulates in the subarachnoid space and

ventriclesventricles Eventually reabsorbed into the Eventually reabsorbed into the

bloodstreambloodstream

SpacesSpaces

Epidural – between inner skull and outer Epidural – between inner skull and outer dura (meningeal artery)dura (meningeal artery)

Subdural – between inner dura and outer Subdural – between inner dura and outer arachnoid – (veins)arachnoid – (veins)

Subarachnoid – CSF filled space between Subarachnoid – CSF filled space between arachnoid and pia (arteries) arachnoid and pia (arteries)

Ventricular SystemVentricular System

Saggital View - MRISaggital View - MRI

Brain ParenchymaBrain Parenchyma

Gray MatterGray Matter Cell bodies; 6 layersCell bodies; 6 layers 1 = mainly dendrites; 2 & 3 = cortical-cortical 1 = mainly dendrites; 2 & 3 = cortical-cortical

connections; 4 = inputs from thalamus; 5 = connections; 4 = inputs from thalamus; 5 = outputs to subcortex; 6 = projects to thalamusoutputs to subcortex; 6 = projects to thalamus

White MatterWhite Matter Myelinated tracks that transmit information Myelinated tracks that transmit information

across the brainacross the brain

White / Gray Matter White / Gray Matter DifferentiationDifferentiation

Coronal View

Sulci & Gyri

Lateral & Central Sulci - demarcations

Four Lobes of the BrainFour Lobes of the Brain

BrainstemBrainstem

BrainstemBrainstem

Parts of the CNSParts of the CNS Telecephalon Telecephalon

Cortex, subcortial WM, BG, basal forebrainCortex, subcortial WM, BG, basal forebrain

DiencephalonDiencephalon Thalamus, hypothalamusThalamus, hypothalamus

Mesencephalon (midbrain)Mesencephalon (midbrain) Peduncles, tectum, tegmentumPeduncles, tectum, tegmentum

Rhombencephalon (hindbrain)Rhombencephalon (hindbrain) Metencephalon – pons, cerebellumMetencephalon – pons, cerebellum Myelencepalon – medullaMyelencepalon – medulla

Spinal CordSpinal Cord

Cerebral VasculatureCerebral Vasculature

Cerebral VasculatureCerebral Vasculature

Cerebral VasculatureCerebral Vasculature

Brain Injury Overview

Focal Polar

Diffuse Axonal

Secondary/Anoxic

Types of Brain Damage

Open Head InjuryOpen Head Injury

Skull is fractured or penetrated by foreign Skull is fractured or penetrated by foreign objectobject

Majority of cases resulting from traumaMajority of cases resulting from trauma Primary Effects – actual damage due to Primary Effects – actual damage due to

trauma (e.g., cortical damage)trauma (e.g., cortical damage) Secondary Effects – cascade effects of Secondary Effects – cascade effects of

primary trauma (e.g., edema)primary trauma (e.g., edema) Better PrognosisBetter Prognosis

Closed Head InjuryClosed Head Injury

No skull fracture – vascular, hypoxicNo skull fracture – vascular, hypoxic Primary Effect – contusion or axonal Primary Effect – contusion or axonal

shearing or bleedshearing or bleed Secondary effect – edema or Secondary effect – edema or

hydrocephalus (due to bleed or CSF hydrocephalus (due to bleed or CSF collection) – can result in midline shift collection) – can result in midline shift of structuresof structures

Injuries resulting from traumaInjuries resulting from trauma

Coup injuryCoup injury Injury to the brain tissue on the same side as Injury to the brain tissue on the same side as

the impactthe impact Contracoup injuriesContracoup injuries

Injury to brain tissue opposite the side of Injury to brain tissue opposite the side of impact, due to brain hitting the skullimpact, due to brain hitting the skull

Diffuse Axonal InjuryDiffuse Axonal Injury Due to rotational forcesDue to rotational forces

Injuries resulting from traumaInjuries resulting from trauma

HydrocephalusHydrocephalus

Intracranial pressureIntracranial pressure HerniationHerniation Midline shiftMidline shift

Brain Injury SeverityBrain Injury Severity

LOC – loss of consciousnessLOC – loss of consciousness Mild injury < 30 minutesMild injury < 30 minutes Moderate/severe injury > 30 minutesModerate/severe injury > 30 minutes ComatoseComatose

PTA – post traumatic amnesia/delirium - PTA – post traumatic amnesia/delirium - significant disturbance of memory and significant disturbance of memory and mood/personality following TBImood/personality following TBI mild PTA < 1 hourmild PTA < 1 hour moderate PTA 1-24 hoursmoderate PTA 1-24 hours severe PTA > 24 hours severe PTA > 24 hours

Glascow Coma Scale (out of 15)Glascow Coma Scale (out of 15) mild = 13mild = 13 moderate = 9-12moderate = 9-12 severe = 8 or lesssevere = 8 or less

Neuropsychological SequelaeNeuropsychological Sequelae

Attention/Processing SpeedAttention/Processing Speed LanguageLanguage MemoryMemory VisuospatialVisuospatial Executive FunctionsExecutive Functions Psychological/PersonalityPsychological/Personality

Sensory/Motor/Neurological Sensory/Motor/Neurological SequelaeSequelae

HemiparesisHemiparesis Visual deficitsVisual deficits Muscle SpasticityMuscle Spasticity Bowel and bladder dysfunctionBowel and bladder dysfunction SeizuresSeizures Poor Sensory Integration Poor Sensory Integration PainPain

Cortical Functions by RegionFrontal Lobe

- Initiation

- Problem-Solving

- Judgment

- Inhibition of Behavior

- Planning/Organization

- Self-Monitoring

- Motor Planning

- Personality/Emotions

- Mental Flexibility

- Expressive Language

Temporal Lobe- Memory

- Audition

- Receptive Language

- Emotion

Parietal Lobe- Sensory input and integration

- Spatial perception

Occipital Lobe- Vision

- Visual Integration

Brain Stem

Cerebellum- Balance

- Motor Coordination

- Skilled Motor ActivityBrain Stem-Breathing/Heart Rate

-Arousal

Brain StemBrain Stem

Before & After

Massive hemorrhagic strokeMassive hemorrhagic stroke

Brain Tumor (Glioma)Brain Tumor (Glioma)

The Story of Phineus Gage(1848)

"He is fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom) capricious and vacillating, devising many plans of future operation, which are no sooner arranged than they are abandoned. Previous to his injury, although untrained in the schools, he possessed a well balanced mind, and was looked upon by those who knew him as a shrewd, smart businessman, very energetic and persistent in executing all his plans of operation."

-Dr. John Harlow

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