Transcript CNS Pathology - El Camino College

CNS Pathology
RT 91
Fall 2010
Final
INFLAMMATORY
DISEASE OF CNS
Meningitis

Inflammation fo the meningeal coverings of the brain and
spinal cord

Can be caused by




Bacterial is most common (can cause hydrocephalus)
Three types pus forming bacteria:




Bacteria, virus and other organisms via blood or lymph
Trauma, pentrating wounds or adjacent structures infected
Meningococci - infants
Streptococci - children
Pneumococci- adults
Tubercle bacillus
Different Pathogens causing
Meningitis

Fungi



Virus


Chronic meningitis
Often associated with AIDS and immunodepressant
drug therapy
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
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
Diagnosis of Meningitis

Brain CT


Spinal tap


LP to remove CSF to send to lab
Sometimes MRI is used


Rule out contraindications to do a spinal tap
Is most sensitive modality for demonstrating pia and
arachnoid
Treatment includes antibiotics and if secondary
to encephalitis: antiviral drugs
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
Encephalitis
 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
Encephalitis

MRI is modality of
choice

Results in cerebral
edema and
hemorrhagic lesions

More serious than
meningitis because it
frequently develops
permanent neurologic
disabilities
Encephalitis:
Symptoms and Treatment

Symptoms:

Headache

Malaise

Treatment:



Coma

Fever

Seizures
Treated with antiviral
medications
Herpes induced is
treated with Acyclovir
• Interferes with DNA
synthesis and inhibits
viral replication
CONGENITAL
DISEASES OF CNS
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
Types of Spinal Bifida

Meningocele



Myelocele


Protrusion of spinal cord
Meningomelocele



Only the meninges protrude
Local defect of bone & dura
Protrusion of meninges and
spinal cord into the skin of the
back
Most serious
Spinal bifida occulta


No protrusion of spinal
contents
Least severe
Radiographic Appearance
Meningomyelocele

Can be demonstrated
with CT, MRI and
myelography

Prenatally with
ultrasound (in utero)
Meningocele

Large bony defects

Herniated spinal
contents
Meningomyelocele

Most serious
 Affected PT’s have
severe neurologic
deficits



Paraplegia
Diminished control of
lower limbs, bladder
and bowels
Hydrocephalus is
common
Spinal Bifida Imaging
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
CRANIAL AND SPINAL
FRACTURES
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
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

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
Linear Fractures
Linear Skull FX
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
Depressed Skull FX
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
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
Compression FX of Spine
Compression FX of Spine
Hangman’s Fracture
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
 FX

Now seen more for MVA
Hangman’s Fracture
Hangman’s Fracture
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
Jefferson’s Fracture
Jefferson’s
Fracture
TRAUMATIC DISEASE
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


PT usually loses consciousness and cannot
remember traumatic event
Persitent LOC over 24 hrs is a coma and can
be fatal
CT appearance of
Cerebral Contusion

CT scans appear as low density areas of edema
and tissue necrosis



With or without homogenous density zones reflecting
areas of hemorraghe
Most common sites of injury are frontal and anterior
temporal regions.
When IV contrast is used it will enhance several
weeks after injury
 Plays an important role in diagnosis
MR of Cerebral Contusion
 Cerebral
edema causes high signal
intensity on T2 scans
 T1
scans may produce high signal regions
 Diagnosis
PET
can also include CT, MRI and
Cerebral
Contusion

Treatment:

PT is hospitalized
• Prevent shock

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Clinical symptoms:





Drowsiness
Confusion
Agitiation
Hemiparesis
Unequal pupil size
If there is swelling
meidcation is given to
decrease cranial
pressure
• Control edema
• Draniage of hematoma

Surgery is usually not
necessary
Cerebral Contusion
Hematomas

Brain trauma often resulting in a hemorrhaging
from a ruptured vein or artery



Venous bleeding occurs more slowly than arterial
bleeding
Arterial bleed accumulates fast & causes neurologic
symptoms & coma
Both can cause edema in the brain and cause an
increase in intracranial pressure

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
Epidural Hematomas

Highest mortality relate of the hematomas


Results from a torn artery and its branches



Even when treated quickly mortality rate is 30%
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
Epidural Hematoma
Usually a shift of midline
Toward opposite side
CT shows increased
density
Emergency surgical
decompression is required to
relieve cranial pressure
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
Occurs more slowly
Because it is a venous
Hemorrhage.
On CT appears as a
curvilinear area of I
increased density on
portions or all of the
cerebral hemispheres
Subdural Hematomas
 Subacute

 In


stage (up to several days)
Appears on CT as a decreased density or
isodense fluid collection
chronic state (2-3 weeks)
The surface of the hematoma becomes
concave
Delayed coma con occur
Symptoms of Hematomas
 Headaches
 Agitation
 Drowsiness
 Gradual
radiograph deficits
Treatment of Hematomas

In small hematomas without inclination to
rebleed



Severe cases



the hemorrhage is reabsorbed naturally
no treatment is necessary
Require surgical ligation
Evacuation of hematoma to prevent herniation
Less invasive treatment may include


Drug therapy
Intraventricular catheter to remove CSF, which may
cause herniation
Degenerative Diseases

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
Herniated Disk
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
Herniated Disk
Herniated Disk

MRI is modality of choice

CT and Myelography can also be used
Symptoms of Herniated Disk
 Sudden

weak & severe onset of pain
Weakened muscles
 Compression

Cause pain and weakness in neck & upper
extremities
 Compression

of nerve roots in C-spine:
in lumbar in L-spine:
Causes pain in hip, posterior thigh, calf and
foot (sciatica)
Treatment: Herniated Disk
 Conservative



Bed rest, analgesics and muscle relaxants
Followed by physical therapy
95% recover is 3 months without surgery
 Surgical




treatment:
intervention
Diskectomy
Surgical decompression
Spinal fusion
Laminectomy
Herniated Disk: Fusion
Brain & Spinal
Tumors
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
Symptoms of Spinal Tumors

Extramedullary


Similar symptoms as a
herniated nucleus
pulposus
Compress nerve roots
leading to pain and
muscle weakness

Intramedullary


Can cause
progressive
paraparesis
Sensory loss
Extramedullary Spinal Tumors
Neurofibroma
Meningioma
Intramedullary Spinal tumors
Astrocytoma
Ependymoma
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
Treatment of Spinal Tumors
 Both
intramedullary and extramedullary
can be removed surgically

 In

50% of patients who have surgery experience
a reverse of clinical anomalies
cases where surgery is contraindicated
Radiation therapy is the primary means of
treating a tumor
Brain Tumors

Gliomas acct for 50% of all brain tumors



Types of gliomas include: Astrocytoma &
ependymoma
Ependymomas predominate in 3-4 yr olds
Meningiomas are the most frequently occurring
nonglial tumors


Primarily affecting adults around 50 yrs old
They are non-aggressive

All tumors have greater incidence in males

Interfere with circulation of the CSF causing a
hydrocephalus
Brain Tumors
 In
children 20% of all tumors are brain
tumors


60 – 70% are located in the cerebellum &
posterior fossa
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
Astrocytomas of Brain
Usually treated
with surgery and
radiation therapy
Have good 5
year survival
rate
Ependymoma of Brain
Usually treated with surgical removal
Medulloblastomas of Brain
Craniopharyngliomas of Brain
Metastatic Tumor of Brain
Meningiomas of Brain
Usually benign
More frequent in women
Rare in children
Less common to see
in brain than spinal cord
Symptoms of Brain Tumors




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
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

Headache
Nausea and Vomiting
Lethargy
Seizures
Paralysis
Aphasia
Blindness
Deafness
Abnormal changes in personality & behavior
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

Can be congenital or acquired
 Refers to an excessive amount of fluid in the
ventricles
 Two types

Non- communicating
• Interferes or blocks normal CSF circulation from the
ventricles to the subarachnoid space

Communicating
• Poor absorption of the CSF by the arachnoid Villi

Least common cause is from overproduction of CSF
Hydrocephalus

Non-communicating




Can be congenital
Can be from tumor
growth
Trauma (hemorrhage)
Inflammation

Communicating




Can come with
increased cranial
pressure
Raised intrathoracic
pressure impairing
venous flow
Inflammation from
meningitis
Subarachnoid
hemorrhage
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
Hydrocephalus
Hydrocephalus
Hydrocephalus Clinical Symptoms





The cranial size is
enlarged
Scalp veins distended
Skin of scalp thin,
fragile and shiny
Neck muscles
underdeveloped
•In adults
Severe cases
•ALOC
 Orbital roofs are
•Ataxia
depressed
•Incontinence
 Eyes displaced
•Decreased intellectual
downwards
•capabilities
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
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
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

Communicating



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

Non-communicating


Obstruction between
ventricles and cauda
equina
Most common form of
obstructive
hydrocephalus is from
abnormalities between
the 3rd and 4th
ventricles
Multiple Sclerosis
 Chronic
progressive disease of the
nervous system

Affects women more than men at approx 2040 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
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

Difficulty speaking
clearly

Poor coordination


Bladder dysfunction
Tremors
 Muscle weakness

Muscle impairment

Double vision

Loss of balance

Nystagmus (rapid eye
movement)
HALLMARKS OF MS :
SPINAL
CORD
BRAIN
DEMYELINATION AREAS
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
Multiple Sclerosis: MRI
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

Immunosuppressive
agents


Corticosteroids (short
term)

Limit the autoimmune
attack


Antiviral


Slows the progress of the
disease
Beta interferon



Immunomodulatory agents
that reduce the severity of
the attacks
Given subcutaneously

Shortens the symptomatic
periods
Delays progression of
disease
Reduces frequency of
attacks
Regular exercise

Reduces spasms and
increases ROM
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:


Both CT and MRI distinguish between the two
types



Ischemic and Hemorrhagic
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
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 modalites are
questionable
Symptoms of Thrombotic
Ischemic Stroke

Sypmtoms come on over horus 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
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)
Ischemic Stroke
Imaging of Ischemic Stroke

Non-contrast CT scans are most commonly used




Before treatment with thrombolytic agents
Best success if within 45 minutes of stroke
Follow up CT or transcranial US used after meds to monitor
success or meds
MRI is also excellent for imaging

In some cases more accurate than CT in identifying EARLY
infarct signs

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

Shows promise but not currently used freqently
Hemorrahgic Stroke

Occurs from a weaknening in the diseased
blood vessel

Typically weakened from atheroscleosis from
hypertension

Sudden and often lethal because it comes on so
suddenly

Accoutns for 10-15% of all CVA’s

Two types:

Subarachnoid and Intracerebral
Hemorrahgic 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
Imaging of Hemorrahgic Strokes
 CT



is modality of choice
Can demonstrate high density blood in the
subarachnoid space in more than 95% of
cases
Can demonstrate aneurysms greaeter than
3mm
With contrast is contraindicated because
surgeon will not operate without an angiogram
 MRI
is relatively insensitive for
subarachoid bleeds
Treatment of
Hemorrahgic Strokes
 Surgery

 If
Preceded by a surgical angiogram
surgical intervention is postponed so will
the angiogram
Hemorrahgic Stroke
Pathology Summary and
Modality of Choice



Pathology Summary: Central Nervous
System
Pathology Imaging Modalities of
Choice Additive or Subtractive
Pathology
Hydrocephalus


Meningitis


MRI, CT, myelography
Cervical spondylosis
Radiography Subtractive
Multiple sclerosis


CT, MRI
Herniated nucleus pulposus




MRI
Brain abscess


MRI
Encephalitis


CT, MRI, sonography in the neonate
MRI
CVA

MRI, CT, sonography, PET

Glioma


Medulloblastoma


MRI
Spinal tumor


CT
Acoustic neuroma


CT, MRI
Craniopharyngioma


CT, MRI
Pituitary adenoma


MRI, CT
Meningioma


MRI, CT
MRI, radiography, CT, myelography
Both Metastases from other sites

MRI, radiography, CTSubtractive