CNS Pathology - El Camino College
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Transcript CNS Pathology - El Camino College
CNS Pathology
RT 91
Spring 2012
1
INFLAMMATORY
DISEASE OF CNS
2
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
3
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
4
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
5
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
6
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
7
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
8
Encephalitis
MRI is modality of
choice
Results in cerebral
edema and
hemorrhagic lesions
More serious than
meningitis because it
frequently develops
permanent neurologic
disabilities
9
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
10
CONGENITAL
DISEASES OF CNS
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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
12
Types of Spinal Bifida
Meningocele
Myelocele
Protrusion of spinal cord
Meningomyelocele
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
13
Radiographic Appearance
Meningomyelocele
Can be demonstrated
with CT, MRI and
myelography
Prenatally with
ultrasound (in utero)
Meningocele
Large bony defects
Herniated spinal
contents
14
Meningomyelocele
Most serious
Affected PT’s have
severe neurologic
deficits
Paraplegia
Diminished control of
lower limbs, bladder
and bowels
Hydrocephalus is
common
15
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 AND SPINAL
FRACTURES
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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
19
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
20
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
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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
23
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
25
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
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
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Hangman’s Fracture
30
Hangman’s Fracture
31
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
32
Jefferson’s Fracture
33
Jefferson’s
Fracture
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TRAUMATIC DISEASE
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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
PT usually loses consciousness and cannot
remember traumatic event
Persitent LOC over 24 hrs is a coma and can
be fatal
36
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
37
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
38
Cerebral
Contusion
Treatment:
PT is hospitalized
• Prevent shock
Clinical symptoms:
Drowsiness
Confusion
Agitiation
Hemiparesis
Unequal pupil size
If there is swelling
medication is given to
decrease cranial
pressure
• Control edema
• Drainage of hematoma
Surgery is usually not
necessary
39
Cerebral Contusion
40
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
41
Epidural Hematomas
Highest mortality rate 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
http://www.youtube.com/watch?v=cVUofakFIyw&feature=related
42
Epidural Hematoma
Usually a shift of midline
Toward opposite side
CT shows increased
density
Emergency surgical
decompression is required to
43
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)
http://www.youtube.com/watch?v=qO16QX
MxBLY&feature=related
44
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
45
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
46
Symptoms of Hematomas
Headaches
Agitation
Drowsiness
Gradual
radiograph deficits
47
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
48
Degenerative Diseases
49
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
50
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
51
Herniated Disk
52
Herniated Disk
MRI is modality of choice
CT and Myelography can also be used
53
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)
54
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
55
Herniated Disk: Fusion
56
Brain & Spinal
Tumors
57
Spinal Tumors
Primary
tumors are 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
58
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
59
Extramedullary Spinal Tumors
Neurofibroma
Meningioma
60
Intramedullary Spinal tumors
Astrocytoma
Ependymoma
61
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
62
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
63
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
64
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
65
Astrocytomas of Brain
Usually treated
with surgery and
radiation therapy
Have good 5
year survival
rate
66
Ependymoma of Brain
Usually treated with surgical removal
67
Medulloblastomas of Brain
68
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
71
Symptoms of Brain Tumors
Headache
Nausea and Vomiting
Lethargy
Seizures
Paralysis
Aphasia
Blindness
Deafness
Abnormal changes in personality & behavior
72
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
73
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
74
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
75
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
76
Hydrocephalus
77
Hydrocephalus
78
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
79
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
http://www.youtube.com/watch?v=0h7XaLsnac
Ventricularjugular Shunt
http://www.youtube.com/watch?v=Qmym2i
FVNw8
80
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
81
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
82
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
83
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 its origin is unknown
Treatment only slows the process
Some research indicates it may come from
herpes or retrovirus
Appears more in temperate climates than
tropical climates
84
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
85
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)
86
HALLMARKS OF MS :
SPINAL
CORD
BRAIN
DEMYELINATION AREAS
87
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
88
Multiple Sclerosis: MRI
89
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)
90
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
91
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
http://www.youtube.com/watch?v=pcmrgwNCPwM&feature=relmfu
92
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
93
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
94
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)
95
Ischemic Stroke
96
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
97
Hemorrahgic 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
98
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
99
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
100
Treatment of
Hemorrahgic Strokes
Surgery
Preceded by a surgical angiogram
If
surgical intervention is postponed so will
the angiogram
101
Hemorrahgic Stroke
102
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
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
MRI
CVA
MRI, CT, sonography, PET
103