Nervous system Flashcards
Read over the list of the following pathologies
Meningitis
Hydrocephalus
Tumours of the CNS
Traumatic Processes of the Brain and Skull
CNS Vascular Disease
Degenerative Diseases of the CNS
What is meningitis?
Acute inflammation of the pia and arachnoid maters (meninges)
Where does the infection from meningitis stem from in the body?
Infection from middle ear, URT, or frontal sinus, or through bloodstream
What are the causes of meningitis?
1.Viruses
2.Bacteria
What is the most common cause of meningitis?
Viruses
What type of meningitis is more severe?
Bacterial
What are the symptoms of meningitis?
Headache, fever, stiff neck, sensitivity to light and loud noises, loss of appetite
What test is done to confirm Meningitis?
Lumbar puncture
What imaging is best to image meningitis?
MRI is the best
What does an MRI show with meningitis?
-Increased signal in cisterns, interhemispheric fissure, and choroid plexus with gadolinium
T/F
CT used as well to image meningitis
True
What are the complications of meningitis?
-Swelling of the brain –> Increased intracranial pressure
-Subdural empyema or brain abscesses
-Encephalitis
What is Hydrocephalus?
Dilation of the ventricular system
Hydrocephalus causes increased intracranial pressure
True
What are the Two types of Hydrocephalus?
1.Non-communicating (obstructive)
2.Communicating
Where in the brain does non communicating Hydrocephalus affect?
-CSF flow blocked somewhere from the lateral ventricles to the Fourth ventricle
-Most common in the cerebral aqueduct (everything before appears dilated, everything after appears normal)
Where does CSF flow with communicating hydrocephalus? Where does obstruction occur?
-CSF flows freely into subarachnoid space
-Obstruction occurs in cisterns other areas of the subarachnoid space
What is the cause of hydrocephalus?
From over production (could be from a tumour or an issue with absorption from the arachnoid villi)
What imaging is done for hydrocephalus?
CT, Contrast MRI, Ultrasound
What does a CT of hydrocephalus demonstrate?
CT demonstrates ventricular enlargement (appears black)-shows up well on a CT scan
Why is contrast MRI done for hydrocephalus?
Contrast MRI best demonstrates the reason for the obstruction
When is ultrasound used for hydrocephalus?
-Ultrasound can be used when fontanels are open (pediatric patient)
T/F
Hydrocephalus is better in pediatric patients than in adults
True
What are the treatments for hydrocephalus?
-VP shunt (ventricular peritoneal shunt)
(Line in lateral ventricles to the peritoneum releasing extra fluid)
What are the Tumours of the CNS?
Glioma
Meningioma
Metastatic Carcinoma
T/F
All tumours of the CNS enhance in some way with contrast
True
What is the most common primary malignant brain tumour?
Glioma
What is a Glioma composed of?
Composed of glial cells
How does Glioma spread?
Spread by direct extension
What are the types of Gliomas?
Glioblastoma and Astrocytoma
Is Astrocytoma slow or fast growing?
Slow growing, infiltrating
What type of Glioma is More common?
Astrocytoma
T/F
Astrocytoma can form large cavities
True
What Glioma is more aggressive and highly malignant?
Glioblastoma
Where is Glioblastoma commonly located?
Commonly in cerebrum
What tumour of the CNS is this describing?
Enhances a lot and appears more irregular
Glioblastoma
T/F
All gliomas show contrast enhancement
True
Gliomas typically occur early in life
False; Gliomas typically occur later in life
What will a CT of a Glioma show?
-Peripheral rim will be enhanced with edema on the outside
-Extra fluid in the area and will seep out
What is Meningioma?
Benign tumour of the meninges
Is Meningioma slow or fast growing?
Slow growing
What imaging is best for Meningioma?
C+with MRI and CT are best
How does Meningioma appear radiographically?
–Rounded, sharply delineated isodense or hyperdense lesion
-Uniform, bright enhancement (no rim, entire thing)
What are the Most common sites for Meningioma?
-Convexity of the calvarium
-Parasagittal region
T/F
Meningioma will cause neurological defects as it compresses the brain tissue
True
Where does Metastatic Carcinoma commonly come from?
-Commonly from primary cancers of lung and breast
What does contrast studies with CT and MRI show with Metastatic Carcinoma?
-Multiple enhancing lesions of various sizes (not just one)
-Enhance w/ surrounding low density edema
-Usually at junction of gray/white matter
What does a non contrast scan of Metastatic Carcinoma show?
-Can be hypodense, isodense, or hyperdense
What are the Traumatic Processes of the Brain and Skull?
Skull Fracture
Epidural Hematoma
Subdural Hematoma
Subarachnoid Hemorrhage
Cerebral Contusion
Facial Fractures
What is the modality of choice for skull fractures?
CT is the modality of choice
What are the Types of Skull Fractures?
1.Linear skull #
2.Depressed skull # (star-shaped)
3.Basal skull # (at the base of the skull)
Basal skull fractures are difficult to see even with CT
True
What are the Risks with Basal skull fractures?
May cause leakage of CSF, meningitis, damage to facial nerve or cochlea/semi-circular canals
What are the Clinical Signs of Basal skull #?
Raccoon Eyes and Battle’s Sign
Where is the fracture located if the raccoon eye sign is shown?
Fracture of the anterior cranial fossa tears the meninges
Where is the fracture located if the battle’s sign is shown?
Fracture of the middle cranial fossa
What is an Epidural Hematoma caused by?
Caused by acute arterial bleeding (has higher blood pressure-Bleeds faster)
Where is a Common area for Epidural Hematomas to occur? What can an Epidural Hematoma in this area lead to?
The parietotemporal junction which can cause Laceration of middle meningeal artery
T/F
Epidural Hematomas are strongly associated with linear skull #
True
T/F
Epidural Hematomas Rapidly cause significant mass effect and acute neurologic symptoms
True
What are the symptoms of Epidural Hematomas?
-Post trauma decrease in neurologic function, ipsilateral (same side) pupil dilation, LOC, increase in ICP, compression of brainstem if too much pressure-
may need a craniotomy
T/F
The Epidural mater is below the dura mater
False; The Epidural mater is above the dura mater
How does an Epidural Hematoma radiographically?
-Appears as a biconvex (lens-shaped), peripheral (because its in the epidural space), high-density lesion
What are Epidural Hematoma limited by in the brain?
-Limited by the sutures because the dura matter is fused
-This is why it makes the Lense shape
What treatment is required for Epidural Hematoma?
Emergency surgery required
(Craniotomy and Burr holes)
Where is a Subdural Hematoma located?
Between dura and arachnoid maters
What are Subdural Hematomas caused by?
-Caused by tearing of the bridging veins leading to the dural sinuses
-Venous bleeding (VEINS BLEEDING)
What are the symptoms of Subdural Hematoma?
-Headache, agitation, confusion, drowsiness, and gradual deficits
How do Subdural Hematomas appear radiographically?
-Crescent-shaped mass that is typically more extensive than EDH
-Because it is not bound by the duras
-Below the epidural
T/F
A Subdural Hematoma is more gradual usually compared to the epidural hematomas
True
What are the 3 types of Subdural Hematomas?
1.Acute Subdural
2.Subacute
3.Chronic Subdural
When does an Acute Subdural hematoma appear?
after first hour or so
How does an Acute Subdural hematoma appear radiographically?
Appears brighter on CT (more defined)
Hey Josie, you got this. Give yourself a break. It’s going to be okay.
When does a Subacute subdural hematoma appear?
typically 10-14 days or 3 days to 3 weeks
How does a Subacute subdural hematoma appear radiographically?
Isodense
When does a Chronic Subdural hematoma appear?
> 3 weeks
How does a chronic Subdural hematoma appear radiographically?
Appears darker on CT
What are the symptoms of a Subarachnoid Hematoma?
Symptoms:
-“Worst Headache of Life”
-Nausea/vomiting
-Photophobia
-Spinal fluid may be bloody
-Patients are conscious
What are the causes of a Subarachnoid Hematoma?
1.Trauma
2.Ruptured cerebral aneurysm
What imaging is done for Subarachnoid Hematomas?
-Non-contrast CT scan
How does a Subarachnoid Hematoma appear on a non Contrast CT scan?
-Bright areas around the Circle of Willis, cisterns, cerebral fissures and sulci
What is a Brain Contusion?
Brain bruise (multiple microhemorrhages) of cerebral cortex from rapid violent movement of brain against rough skull surface
What facial and cranial bones are injured with brain contusions?
Petrous ridges and Orbital roofs
-Injury could be coup or contrecoup (other side)
What modality is used to image brain contusions?
CT-No contrast
How do brain contusions appear radiographically?
-low-density areas of edema and necrosis
-may have mixed densities if blood is present
-If it is actively bleeding it will appear brighter
What are the types of facial fractures?
Nasal bone fractures
Blow out fractures of the orbit
Le Fort fractures of the maxillae
Mandibular fractures
T/F
Nasal bone fractures range from simple, non-displaced linear fractures to comminuted, depressed ones
True
What Imaging is done for nasal bone fractures? (Specific)
-Bilateral lateral projections
-Waters’ method
What does the waters method show for nasal bone fractures?
Shows deviation of the bony septum
What are blow out fractures of the orbit caused by?
-Direct blow to the front of the eye ball
Where do blow out fractures of the orbit occur?
-Fracture occurs in the weakest spot – floor of the orbit
What is the best position to image Blow out fractures of the orbit?
Modified Waters’ method is preferred radiographic image
What does the modified waters method show in Blow out fractures of the orbit?
-Shows fluid level in maxillary sinus
-Shows the floor better
T/F
CT is often required for low out fractures of the orbit? Why or why not?
True
-Demonstrates muscle herniations
(See bone in more detail and seeing if the muscles are herniating downwards into the sinus)
What are the three types of Le Fort fractures of the maxillae?
1 2 and 3
What does Le Fort fractures of the maxillae require??
Requires ORIF
Where is the fracture located with type 1 Le Fort fractures of the maxillae?
-Horizontal through the maxilla
Where is the fracture located with type 2 Le Fort fractures of the maxillae?
Up through the maxilla and lacrimal bones
Where is the fracture located with type 3 Le Fort fractures of the maxillae?
Zygomatic arch, lateral rim of the orbit, across the nose
What fracture is this describing?
Zygomaticomaxillary complex fracture
Tripod Fracture
What bones are fractured with Tripod Fracture?
Fracture of the zygomatic arch, inferior orbital rim/maxillary sinus walls, and lateral orbital rim
T/F
Tripod Fractures can result in free floating zygomatic bone
True
What is the most common type of Mandibular fractures?
-Contrecoup fractures are common because mandible is round
What is a contrecoup fracture?
Fractures through ramus or body of mandible
What imaging is done for Mandibular fractures?
-May see panoramic tomography
You’re doing great.
What are cerebral vascular diseases?
A Group of conditions that affect blood supply to the brain, causing limited (ischemia) or no blood flow (infarction) to the affected areas
What is this describing?
Weakening or ballooning of vessel wall (usually one part of the wall is weaker leading to a balloon coming off the side
Anurysm
Where is the most common spot for anurysms to happen?
Circle of Willis
Read over the following cerebral vascular diseases:
1.Vessel wall abnormality
2.Thrombus (developing along that vessel) or emboli
3.Rupture of vessel = hemorrhage
4.Aneurysm =
5.Arteriovenous malformations (AVM’s)
What are the three main categories of cerebrovascular diseases?
1)Stroke or Cerebrovascular Accident (CVA)-
2)Transient Ischemic Attacks-
3)Intracranial Hemorrhage
What are the two types of intracranial hemorrhages?
a.Subarachnoid Hemorrhage
b.Intraparenchymal Hemorrhage (within that brain tissue-there is a bleed there)
What are TIAs?
Mini strokes with similar symptoms-resolve on their own
What is a Stroke or Cerebrovascular Accident (CVA)?
Sudden development of a focal neurologic deficit
What are the symptoms of stroke/CVA?
1.Hemiplegia
2.Hemiparesis
3.Facial droop
4.Dysphasia
5.Dysarthria
What is dysphasia?
Issues with speaking-trouble getting the words out and saying them)
Aphasia (more severe-Brain thinks its saying one thing, but its saying another or not being able to speak at all)
What is hemiplegia?
Paralysis of one side of the body
What is hemiparesis?
Not a full paralysis-just a weakness of one side of the body
T/F
Internal carotids are commonly involved with strokes/CVA
True
What are the two types of strokes?
1.Ischemic
2.Hemorrhagic
What is an Ischemic Stroke caused by?
-Embolism
-Atherosclerosis in small artery
What is a Hemorrhagic Stroke caused by?
-Rupture of cerebral artery
-AVM or aneurysm burst
What is the first scan done for strokes?
Non contrast CT to rule out a bleed
What has better sensitivity for imaging an ischemic stroke?
-MRI more sensitive initially and later on
T/F
An Initial CT scan of an ischemic stroke may appear normal at first
True
What radiographic signs are seen with ischemic strokes?
1.Low density (hypodense) / attenuation of triangular area that vessel served
2.Mass effect produced by progressive edema is visible 7-10 days post (hypodense)
3.Aged infarct > brain tissue atrophy, ventricular system enlarges
What treatment is given if there is an ischemic stroke with no bleed?
If no bleed…tPA is given
T/F
You can give TPA for a hemorrhagic stroke.
False; Don’t give tPA
What is the radiographic appearance for hemorrhagic strokes?
Would clearly see a hyperdense bleed
Average for ischemic stroke to use TPA is how many hours after onset of symptoms?
3 hours
What is an AVM?
Arteries are connected directly to veins. If you don’t have a capillary bed, the pressure will be too high and they may burst.
-Dangerous
-Arteries designed to hold more pressure veins are not
T/F
Sometimes in the body physician’s decide to connect artery to the vein (good for dialysis)
True
T/F
Sometimes you do use contrast after non contrast scan for a hemorrhagic stroke
True (to see where the blood is coming from)
To image an ischemic stroke, what is the collimation for the scan
(aortic arch and up)
Where is a common place for blockages?
Common place is the carotid bifurcation
What is the final part of a stroke protocol?
CT perfusion study
What is a CT perfusion study?
-Will take repeated scans of the brain, inject contrast and scans over and over again to track where the blood is flowing and how quickly
What is this describing?:
Neurologic deficits that completely resolve within 24 hrs
Transient Ischemic Attacks (TIA’s)
What are the causes of TIA’s?
-Emboli originating from plaque build up on arterial wall (or valves)
-Stenosis of an extracerebral artery (often internal carotid at the bifurcation)
What fracture of arteriosclerotic strokes are preceded by TIA’s?
2/3 of arteriosclerotic strokes preceded by TIA’s
The body breaks up its own clot and resumes normal blood flow
What Initial screening is done for TIA’s?
-Duplex Doppler US
What modality is used post TIA?
Angiography
Read over the following Degenerative Diseases of the CNS:
Alzheimer’s Disease
Parkinson’s Disease
Disc Herniation
Spondylosis
Scoliosis
Kyphosis
Lordosis
What is this describing?
Gradual loss of neurons and enlargement of the ventricular system and sulci
Normal aging
Listen to the soundtrack of prince of egypt-that’s what I’m doing rn :)
What are the radiographic appearances of normal aging?
-Low density appearance around ventricles
-Calcification of choroid plexuses
What is this describing?
Diffuse, progressive cerebral atrophy that develops earlier than normal
Alzheimer’s Disease
What imaging is done for Alzheimer’s Disease?
CT & MRI
How does Alzheimer’s Disease appear radiographically?
-Cerebral atrophy, enlarged ventricles with prominence of the cortical sulci
How does Alzheimer’s Disease appear with nuc med?
Reduced glucose uptake in temporal and parietal lobes
What is Parkinson’s Disease?
Progressive, degenerative disease of nerve cells and inadequate production of neurotransmitter dopamine
How does Parkinson’s Disease appear radiographically?
-Cortical atrophy, ventricle enlargement, prominent sulci
How does Parkinson’s Disease appear in SPECT & PET?
See decreased uptake of glucose
What are the non radiographic signs of Parkinson’s Disease?
-Involuntary rhythmic tremor of the limbs
-Stooped posture
-Stiffness, slow movement
-Fixed facial expressions
What part of the brain is most affected with Parkinson’s Disease?
Basal Ganglia
T/F
Parkisans is more of a gradual onset
True
What is a Disc Herniation
A tear in the annulus fibrosus allows the nucleus pulposus to protrude out compressing a spinal nerve
Where is a disc herniation located?
Possible at any level but most common:
L4/L5, L5/S1
C5/C6, C6/C7
T9 – T12
What modality is best to image disc herniations?
MRI
T/F
As you get older herniations are more common
True
-Over time and with a lot of wear and inflammation they loose elasticity and the inner part starts to protrude outward (sometimes whole disc or only the inner part)
T/F
Herniation can compress spinal nerves or the spinal cord itself
True
What is Spondylosis
General term referring to degeneration of the spine
What are the common pathologies of degeneration of the spine?
Osteoarthritis of the spine or DDD
What is Myelopathy?
compression of the spinal cord
What is Radiculopathy?
Compression of the spinal nerve
T/F
Degeneration of the spine happens as you get older
True
What are some radiographic signs of degeneration of the spine?
-Some of the bodies appear a lot whiter than others
-Seeing osteophyte formation
-Decreased joint space (discs being depressed-could herniate outwards)
-Seeing little black areas-vacuum phenomenon-air inside of the vertebral discs
What is Scoliosis?
Lateral curvature of the spine with rotation towards the convex side of the curve
What are the types of scoliosis?
-Idiopathic
-Functional
-Neuromuscular
-Degenerative
What population is Idiopathic scoliosis common in?
Common in young females
What is Functional scoliosis?
Natural compensation from one limb being shorter
What is Neuromuscular scoliosis?
Congenital vertebrae issues (hemi-vertebra)-or incomplete vertebra
What is Degenerative scoliosis?
Adult form via arthritis
How do you measure the Cobb’s Angle?
Vertebra whose endplates are most tilted towards each other
Angle between these 2 lines are measured
What imaging is done for scoliosis?
Will do image stitching
What does a scoliosis angle of 10-20 indicate?
mild and monitor
What does a scoliosis angle of 21-40 indicate?
Moderate
What does a scoliosis angle of greater than 40 indicate?
severe
What is Kyphosis
-Abnormal kyphotic curve
-Compression #’s of t-spine
What is the cause of kyphosis?
Severe DDD of t-spine
What is Lordosis
Abnormal lordotic curve-C and L spine
What spine is affected with lordosis?
Affects cervical and lumbar spine
What population is lordosis typically found in?
Typically found with pregnant or over-weight people
