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CNS Pathology PowerPoint PPT Presentation

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CNS Pathology. Fall 2009 Final. INFLAMMATORY DISEASE OF CNS. Meningitis. Inflammation fo the meningeal coverings of the brain and spinal cord Can be caused by Bacteria, virus and other organisms via blood or lymph Trauma, pentrating wounds or adjacent structures infected - PowerPoint PPT Presentation

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CNS Pathology

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Cns pathology l.jpg

CNS Pathology

Fall 2009


Inflammatory disease of cns l.jpg


Meningitis l.jpg


  • Inflammation fo the meningeal coverings of the brain and spinal cord

  • Can be caused by

    • Bacteria, virus and other organisms via blood or lymph

    • Trauma, pentrating wounds or adjacent structures infected

  • Bacterial is most common (can cause hydrocephalus)

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Pathogens causing Meningitis

  • ___________________

    • Chronic meningitis

    • Often associated with AIDS and immunodepressant drug therapy

  • ___________________

    • Viral meningitis can be caused by mumps, poliovirus and herpes simplex

  • ___________________

    • Most common

    • Bacteria release toxins that destroy meningeal cells stimulating immune & inflammatory reactions

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Pathogens causing Meningitis

  • Fungi

    • Chronic meningitis

    • Often associated with AIDS and immunodepressant drug therapy

  • Virus

    • Viral meningitis can be caused by mumps, poliovirus and herpes simplex

  • Bacteria

    • Most common

    • Bacteria release toxins that destroy meningeal cells stimulating immune & inflammatory reactions

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Acute Meningitis Clinical Symptoms

  • Fever

  • Headache

  • Stiff neck

  • Vomiting

  • Changes in LOC

  • Severely ill in 24 hours

  • Rash

  • Chronic symptoms are the same but occur over weeks

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Diagnosis of Meningitis

  • Brain CT

    • Rule out contraindications to do a spinal tap

  • Spinal tap

    • LP to remove CSF to send to lab

  • Sometimes MRI is used

    • Is most sensitive modality for demonstrating pia and arachnoid

  • Treatment includes:

    • antibiotics and if secondary to encephalitis: antiviral drugs

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Radiographic Appearance

  • Initially meninges show vascular congestion, edema and minute hemorrhages

  • MRI and CT scans could appear normal if appropriate therapy is done right away

Meningitis as a result of a Staph infection

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  • Infection of the brain tissue that is viral

    • May occur subsequent to chickenpox, small pox, influenza and measles

    • May be caused by mosquitoes and herpes

  • Survival rates depend of cause of the disease (can be fatal)

    • 30% of cases in children

    • When caused by herpes it is often fatal

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  • MRI is modality of choice

  • Results in cerebral edema and hemorrhagic lesions

  • More serious than meningitis because it frequently develops permanent neurologic disabilities

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Treated with antiviral medications

Herpes induced is treated with Acyclovir

Interferes with DNA synthesis and inhibits viral replication

Encephalitis:Symptoms and Treatment

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Spinal Bifida

  • Is a congenital disease

  • Bony neural arch that not completely closed

  • Most common in lumbar region

    • May or may not herniate through opening

  • Can range in risk from treatable to life threatening

  • Can be diagnosed in utero

    • With amniocentesis

    • Ultrasound

    • Elevated beta fetoprotein in mother’s blood

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Types of Spinal Bifida

  • ________________

    • Only the meninges protrude

    • Local defect of bone & dura

  • ________________

    • Protrusion of spinal cord

  • ________________

    • Protrusion of meninges and spinal cord into the skin of the back

    • Most serious

  • ________________

    • No protrusion of spinal contents

    • Least severe

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Types of Spinal Bifida

  • Meningocele

    • Only the meninges protrude

    • Local defect of bone & dura

  • Myelocele

    • Protrusion of spinal cord

  • Meningomelocele

    • Protrusion of meninges and spinal cord into the skin of the back

    • Most serious

  • Spinal bifida occulta

    • No protrusion of spinal contents

    • Least severe

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Radiographic Appearance


  • Can be demonstrated with CT, MRI and myelography

    • Prenatally with ultrasound (in utero)

  • Large bony defects

  • Herniated spinal contents


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  • Most serious

  • Affected PT’s have severe neurologic deficits

    • Paraplegia

    • Diminished control of lower limbs, bladder and bowels

    • Hydrocephalus is common

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Spinal Bifida Imaging

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Spinal Bifida Treatment

  • Can be surgically repaired

    • Neurological damage is permanent still and cannot be reversed

  • Most measures are supportive rather than corrective

    • Physical therapy

    • Physical supports

    • Braces

    • Splints

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Cranial Fractures

  • Cerebral fractures usually occurs to fractures of the calvaria of the skull

  • 3 types of cranial fractures

    • _____________- straight and sharply defined

      • Is 80% of all cranial fractures

    • _____________- curvilinear density

    • _____________- Air fluid levels are indicative

      • Hard to diagnosis radiographically

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Cranial Fractures

  • Cerebral fractures usually occurs to fractures of the calvaria of the skull

  • 3 types of cranial fractures

    • Linear- straight and sharply defined

      • Is 80% of all cranial fractures

    • Depressed- curvilinear density

    • Basilar- Air fluid levels are indicative

      • Hard to diagnosis radiographically

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Cranial Fractures

  • Location of FX is more important that the extent of the FX

    • If FX crosses artery a bleed can occur causing a hematoma

    • Fx that enters mastoid air cells or sinus can cause an infection that can result in

      • Meningitis

      • Encephalitis

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Linear Fractures

  • Non branching lines that are intensely radiolucent

  • Vascular markings are occasionally mistaken for fractures

  • Fracture appears more translucent and transverses the full thickness of skull

  • Sutures

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Linear Skull FX

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Depressed Fracture

  • The fractured edges overlap

  • Usually caused by a high velocity impact with a small object

  • Can cause bleeding into subarachnoid space

  • Best demonstrated with CR tangential to the FX

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Depressed Skull FX

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Basilar Fracture

  • Very difficult to demonstrate with x-ray

    • Air fluid levels in sphenoid sinuses

    • Clouding of mastoid air cells

  • Often X-table lateral is done to demonstrate this

  • CT & MRI are most often used for this type

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Compression Fracture of spine

  • Most frequent type of injury involving vertebral body

  • Generally occurs in T and L-spine

    • T11- T12 and T12 – L1

  • Damage is usually limited to the upper portion of the vertebral body, particularly to the anterior margin

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Compression FX of Spine

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Compression FX of Spine

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Hangman’s Fracture

  • FX of the arch of the 2nd c-spine vertebrae

  • Usually accompanied by anterior subluxation of the 2nd and 3rd cervical vertebrae

  • Sometimes called traumatic spondylosis

  • Resulting from acute hyperextension of the head & neck

  • Originally seen commonly in hangings

    • Now seen more for MVA

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Hangman’s Fracture

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Hangman’s Fracture

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Jefferson’s Fracture

  • Comminuted FX of the ring of the atlas

  • First described as a “burst FX”

    • Generally occurs as a result of severe axial force such as a MVA

  • With this FX particular attn needs to be paid to the transverse longitudinal ligament by reviewing lateral masses on the open mouth odontoid

  • MRI is preferred method for this ligament

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Jefferson’s Fracture

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Jefferson’s Fracture

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Cerebral Contusion

  • Is an injury to the brain tissue caused by a movement of the brain within the calvaria after blunt trauma

  • Occurs when brain contacts rough skull surfaces such as orbital floor and petrous ridges

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CT appearance of Cerebral Contusion

  • CT scans appear as low density areas of edema and tissue necrosis

  • When IV contrast is used it will enhance several weeks after injury

  • Plays an important role in diagnosis

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MR of Cerebral Contusion

  • Cerebral edema causes high signal intensity on T2 scans

  • T1 scans may produce high signal regions

  • Diagnosis can also include CT, MRI and PET

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Clinical symptoms:





Unequal pupil size


PT is hospitalized

Prevent shock

If there is swelling medication is given to decrease cranial pressure

Control edema

Drainage of hematoma

Surgery is usually not necessary

Cerebral Contusion

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Cerebral Contusion

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  • Brain trauma often resulting in a hemorrhaging from a ruptured vein or artery

  • Skull does not allow for expansion and pressure forces brain toward open space (foramen magnum)

  • Can result in major consequences & death if not treated quickly

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Epidural Hematomas

  • Highest mortality relate of the hematomas

    • Even when treated quickly mortality rate is 30%

  • Results from a torn artery and its branches

    • Most often occurs from a FX of the temporal bone

    • 80% of cases conventional radiograph shows fracture

  • Usually meningeal artery with blood pooling between bones of the skull & dura mater

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Epidural Hematoma

Usually a shift of midline

Toward opposite side

CT shows increased


Emergency surgical

decompression is required to relieve cranial pressure

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Subdural Hematomas

  • Between the dura mater & arachnoid meningeal layers

    • Caused by blunt trauma to frontal or occipital lobes and can tear subdural veins

  • Pushes brain away from skull across midline (including ventricles)

Subdural hematoma l.jpg

Subdural Hematoma

Occurs more slowly

Because it is a venous


On CT appears as a

curvilinear area of I

increased density on

portions or all of the

cerebral hemispheres

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Subdural Hematomas

  • Subacute stage (up to several days)

    • Appears on CT as a decreased density or isodense fluid collection

  • In chronic state (2-3 weeks)

    • The surface of the hematoma becomes concave

    • Delayed coma con occur

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Symptoms of Hematomas

  • Headaches

  • Agitation

  • Drowsiness

  • Gradual radiograph deficits

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Treatment of Hematomas

  • In small hematomas without inclination to rebleed

  • Severe cases

  • Less invasive treatment may include

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Degenerative Diseases

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Herniated Disk

  • Disks act as shock absorbers

  • When young nucleus pulposus contains large amount of fluid to cushion spine

  • With increased age the fluid & elasticity decrease leading to degenerative disease and back pain

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Herniated Disk

  • May result from either degenerative disease or trauma

    • A weakened or torn annulus is subject to rupture

    • Nucleus pulposus protrudes & compresses spinal nerve roots

    • Can prolapse in any direction, sometimes without pain

    • When it projects posteriorly there is pain and weakening of muscles supplied by those nerves

    • Most commonly occurs is lower cervical & lumbar

      • Lumbar: Most at L4-L5 and L5 – S1

      • Cervical: Most at C6 – C7

      • Thoracic: T9-T12

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Herniated Disk

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Herniated Disk

  • MRI is modality of choice

    • CT and Myelography can also be used

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Symptoms of Herniated Disk

  • Sudden weak & severe onset of pain

  • Compression of nerve roots in C-spine:

  • Compression in lumbar in L-spine:

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Treatment: Herniated Disk

  • Conservative treatment

  • Surgical intervention

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Herniated Disk: Fusion

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Brain & Spinal Tumors

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Spinal Tumors

  • Primary tumors as less common is spinal cord than those of the brain

  • Divided into extradural and intradural

    • Intradural further divided into

      • Intramedullary (within spinal cord)

        • Most common are: Astrocytoma & Epenymoma

      • Extramedullary (outside spinal cord)

        • Most common types of primary spinal neoplasm's (>60%) are: Meningiomas and Neurofibromas

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Similar symptoms as a herniated nucleus pulposus

Compress nerve roots leading to pain and muscle weakness


Can cause progressive paraparesis

Sensory loss

Symptoms of Spinal Tumors

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Extramedullary Spinal Tumors



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Intramedullary Spinal tumors



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Imaging of Spinal Tumors

  • MRI is the modality of choice

  • Conventional radiography

    • Can demonstrate bony destruction

    • Widening of the vertebral pedicles

    • CT myelo may be necessary to identify extradural tumors

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Treatment of Spinal Tumors

  • Both intramedullary and extramedullary can be removed surgically

    • 50% of patients who have surgery experience a reverse of clinical anomalies

  • In cases where surgery is contraindicated

    • Radiation therapy is the primary means of treating a tumor

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Brain Tumors

  • Gliomas acct for 50% of all brain tumors

  • Meningiomas are the most frequently occurring nonglial tumors

  • All tumors have greater incidence in males

  • Interfere with circulation of the CSF causing a hydrocephalus

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Brain Tumors

  • In children 20% of all tumors are brain tumors

    • Most common are astrocytomas, medulloblastomas, glioblastomas and craniopharyngliomas

      • 30% of primary ped. tumors are medulloblastoma

  • In adults most prevalent are:

    • Astrocytomas, glioblastomas, metastatic tumors and menigiomas

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Astrocytomas of Brain

Usually treated

with surgery and

radiation therapy

Have good 5 year survival rate

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Ependymoma of Brain

Usually treated with surgical removal

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Medulloblastomas of Brain

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Craniopharyngliomas of Brain

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Metastatic Tumor of Brain

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Meningiomas of Brain

Usually benign

More frequent in women

Rare in children

Less common to see

in brain than spinal cord

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Symptoms of Brain Tumors

  • Headache

  • Nausea and Vomiting

  • Lethargy

  • Seizures

  • Paralysis

  • Aphasia

  • Blindness

  • Deafness

  • Abnormal changes in personality & behavior

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Treatment of Brain Tumors

  • Surgical resection

  • Radiation therapy

    • Survival rate for surgery & Radiation therapy combined is 80% over a 5 year period

    • Rate of survival decrease to 3% over a 10 year period

Hydrocephalus l.jpg


  • Can be congenital or acquired

  • Refers to an excessive amount of fluid in the ventricles

  • Two types

    • Non- communicating

    • Communicating

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Can be congenital

Can be from tumor growth

Trauma (hemorrhage)



Can come with increased cranial pressure

Raised intrathoracic pressure impairing venous flow

Inflammation from meningitis

Subarachnoid hemorrhage


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Radiographic Appearance

  • Generalized enlargement of the ventricular system

  • PA radiograph can reveal separation of the sutures

  • CT clearly demonstrates ventricular dilatation

  • MRI is more specific in demonstrating the underlying cause of obstruction or in excluding obstruction

  • Ultrasound is useful in utero and in infants

    • Sound waves transverse open fontanels

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Hydrocephalus Clinical Symptoms

  • The cranial size is enlarged

  • Scalp veins distended

  • Skin of scalp thin, fragile and shiny

  • Neck muscles underdeveloped

  • Severe cases

    • Orbital roofs are depressed

    • Eyes displaced downwards

  • In adults

    • ALOC

    • Ataxia

    • Incontinence

    • Decreased intellectual

    • capabilities

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Treatment of Hydrocephalus

  • Placement of a shunt

    • Internal jugular, heart or peritoneum

    • Contains one way valve to prevent backflow of blood into ventricles

  • Radiographs taken to verify shunt placement

  • CT or MRI done to evaluate success of treatment

Ventricularjugular Shunt

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Hydrocephalus in Infants

  • Affects 1 of every 1000 newborns

  • Long maturation of CNS

  • Can be caused by maternal & fetal infections, fetal hypoxia, irradiation, chemical agents and mechanical forces

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Hydrocephalus In Utero

  • X-ray used to be taken for fetal age and position

  • With hydrocephalic fetus- hard to deliver vaginally

  • Pelvimetry was ordered to determine measurements of inlet and outlet

    • Very uncomfortable

    • Three exposures

Fetal hydrocephalus l.jpg


The flow of CSF is free between ventricles & subarachnoid space about cauda equina

Infants head is normal size but there is bulging of the frontal fontanelles

Caused by poor absorption of CSF


Obstruction between ventricles and cauda equina

Most common form of obstructive hydrocephalus is from abnormalities between the 3rd and 4th ventricles

Fetal Hydrocephalus

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Multiple Sclerosis

  • Chronic progressive disease of the nervous system

    • Affects women more than men at approx 20-40 years of age

  • There is no cure and it s origin is unknown

    • Treatment only slows the process

    • Some research indicates it may come from herpes or retrovirus

    • Appears more in temperate climants than tropical climates

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Multiple Sclerosis

  • Demyelination of the myelin sheath covering nervous tissue of spinal cord & white matter within the brain

  • It has episodes of relapses and remission

  • Eventually leads to neurological damage

    • Impairment of nerve conduction

  • Patients life is not shortened

    • Quality of life is diminished

Symptoms of multiple sclerosis l.jpg

Difficulty speaking clearly

Bladder dysfunction

Muscle impairment

Loss of balance

Poor coordination


Muscle weakness

Double vision

Nystagmus (rapid eye movement)

Symptoms Of Multiple Sclerosis

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Imaging of Multiple Sclerosis

  • Scars from areas of demyelinated nerves

    • Sclerotic lesions throughout nervous system

    • Called MS plaques

  • MRI is modality of choice

    • Contrast enhanced can differentiate active inflammation from older brain plaques

    • Functional MRI assesses alterations in normal CSF function

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Multiple Sclerosis: MRI

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CT imaging of Multiple Sclerosis

  • CT shows old inactive disease

    • Well defined areas of decreased attenuation

  • With contrast, in an acute phase

    • Shows a mixture of decreased density (old)

    • Enhancing regions (active)

Treatment for ms l.jpg

Immunosuppressive agents

Limit the autoimmune attack


Slows the progress of the disease

Beta interferon

Immunomodulatory agents that reduce the severity of the attacks

Given subcutaneously

Corticosteroids (short term)

Shortens the symptomatic periods

Delays progression of disease

Reduces frequency of attacks

Regular exercise

Reduces spasms and increases ROM

Treatment for MS

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Cerebrovascular Accident (CVA)

  • Is an atherosclerotic disease affecting blood supply to the brain

  • 3rd leading cause of death in U.S.

  • 2 types of stroke:

    • Ischemic and Hemorrhagic

  • Both CT and MRI distinguish between the two types

    • MRI is especially sensitive to infarction within hours of onset

    • CT, at times appears negative for a day or so

  • Carotid duplex and MRA are also useful in the diagnosis of a stroke

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Ischemic Stroke

  • Blood clot blocks a blood vessel in the brain

  • Is the majority of strokes

  • Two types:

    • Thrombosis of cerebral artery

      • Blood clot that blocks a blood vessel

    • Embolism of the brain

      • Is a mass of undissolved matter (solid, liquid or gas) present in a blood vessel brought there by blood current

  • Diagnosed with CT and MRI

    • Angiography can be used if other modalities are questionable

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Symptoms of Thrombotic Ischemic Stroke

  • Symptoms come on over hours to days

    • Confusion

    • Hemiplegia

    • Aphasia

  • May be preceded by a temporary episode of nerurologic dysfunction called transient Ischemic attack (TIA)

    • Includes hemiparesis, monocular blindness- clears up in about 2 hours

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Ischemic Stroke: from Embolism

  • Sudden onset of symptoms without warning

  • Mortality rate is 20%

  • Prognosis depends on location, extent, age, and general health

    • Complete recovery is rare

    • Deficits remaining after 6 months are likely to be permanent

  • Treatment

    • Bed rest

    • Clot blockers within 3 hours (recombinant tissue plasminogen activator (rtPA)

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Ischemic Stroke

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Imaging of Ischemic Stroke

  • Non-contrast CT scans are most commonly used

  • MRI is also excellent for imaging

  • CT, MRA and US may offer info regarding patency in the brain and carotid arteries

  • PET may be used in the future to identify decreased Oxygen flow and consumption within the brain

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Hemorrhagic Stroke

  • Occurs from a weakening in the diseased blood vessel

    • Typically weakened from atherosclerosis from hypertension

  • Sudden and often lethal because it comes on so suddenly

  • Accounts for 10-15% of all CVA’s

  • Two types:

    • Subarachnoid and Intracerebral

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Hemorrhagic Stroke

  • Most occur in the cerebrum and bleed into lateral ventricle

  • Most often preceded by an intense headache and vomiting

  • LOC follows in minutes and leads to contralateral hemiplegia or death

  • Prognosis is poor

    • 35% die day after stroke

    • 15% die within a few weeks, usually from another vessel rupture

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Imaging of Hemorrhagic Strokes

  • CT is modality of choice

    • Can demonstrate high density blood in the subarachnoid space in more than 95% of cases

    • Can demonstrate aneurysms greater than 3mm

    • With contrast is contraindicated because surgeon will not operate without an angiogram

  • MRI is relatively insensitive for subarachnoid bleeds

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Treatment ofHemorrhagic Strokes

  • Surgery

    • Preceded by a surgical angiogram

  • If surgical intervention is postponed so will the angiogram

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Hemorrhagic Stroke

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Pathology Summary: Central Nervous System

Pathology Imaging Modalities of Choice Additive or Subtractive Pathology


CT, MRI, sonography in the neonate





Brain abscess


Herniated nucleus pulposus

MRI, CT, myelography

Cervical spondylosis

Radiography Subtractive

Multiple sclerosis



MRI, CT, sonography, PET







Pituitary adenoma




Acoustic neuroma


Spinal tumor

MRI, radiography, CT, myelography

Both Metastases from other sites

MRI, radiography, CTSubtractive

Pathology Summary and Modality of Choice