Week 14: Neurovascular System Pathologies

Question 1

Meningitis

Answer 1

• acute inflammation of the Pia mater and arachnid, two membranes covering the brain and spinal cord
• comes from infection of the middle ear, frontal sinus, respiratory system, bloodstream or other site
• two types: bacterial (pyogenic) which is more common and viral, needs spinal tap to determine which one caused the meningitis
• complications: vasculitis, thrombosis, infarction, hydrocephalus, subdural effusion, emphysema, brain abscess
• damage to blood vessels can result in gangrene and need for limb amputations

Question 1

Meningitis Imaging Appearance

Answer 1

• initially, vascular congestion, edema, and minute hemorrhages from inflammation
• the imaging signs include brain shift and lateral shift of midline structures, obliteration or dilatation of the ventricles and thinning and obliteration of CSF spaces (sulci, sylvian fissures, basal cisterns)

Question 2

Glioma

Answer 2

• most common primary malignant brain tumour
• consists of glial cells (supporting connective tissues in the CNS) which retain ability to multiply
• most common types: glioblastoma, astrocytoma
• spread through direct extension
• can cross from one cerebral hemisphere to the other via corpus callous or other white matter

Question 2

Glioma Radiographic Appearance

Answer 2

• MRI preferred
• CT (non-enhanced): a single heterogeneous mass
• CT (contrast enhanced): a homogeneous lesion with an irregular ring of enhancement

Question 3

Meningioma

Answer 3

• benign tumour that arises from arachnoid lining cells and is attached to the dura
  radiographic appearance:
• MRI
• CT (head): rounded, sharply delineated, hyperdense or isodense tumour abutting dural surface
• may contain calcification
• CT (spine): demonstrates location of spinal meningioma mass as a filling defect

Question 4

Brian Metastases

Answer 4

• usually from lung cancer or breast cancer
• usually through hematogenous (through blood) spread, may be direct invasion
  radiographic appearance:
• MRI
• CT (non-enhanced): lesions that can be hypodense, isodense or hyperdense
• CT (contrast enhanced): multiple enhancing lesions of various sizes

Question 5

Concussion

Answer 5

• traumatic brain injury that can cause lasting effects on Brian tissue and change the chemical balance of the brain
• may cause physical, cognitive and behavioural symptoms and problems both long term and short term
• often include multiple areas of the brain = widespread
• may co-exist with contusion
• may be caused by contrecoup injury
• caused by some kind of head trauma

Question 6

Contusion

Answer 6

• brain contusion = bruise injury to brain tissue (commonly frontal and anterior lobe) caused by movement of there brain within the skull after blunt trauma
• may affect on area of the brain (focal, localized trauma)
• limited area of damage, but damage often more severe
• may be other cause than head trauma

Question 7

Contusion Radiographic Appearance

Answer 7

• CT: low density ares of edema and tissue necrosis demonstrating multiple areas of hemorrhage
• usually frontal and anterior temporal regions
• may enhance for several weeks after a contrast injection because of breakdown of BBB

Question 8

Contrecoup Brain Injury

Answer 8

• injury to brain occurring on opposite side from actual trauma
• French for counterblow
• blunt trauma
• can cause fracture, contusion, concussion
• radiographic appearance: it depends on if fracture, contusion, concussion etc

Question 9

Alzheimers Disease

Answer 9

• presentile dementia
• diffuse form of progressive cerebral atrophy that develops at an earlier age that the senile period
• causes difficulties in day to day functioning and memory of familiar people
• radiographic appearance: CT/MRI: cerebral atrophy with enlarged ventricles and prominent cortical sulci

Question 10

Parkinson’s Disease

Answer 10

• shaky palsy
• progressive degenerative disease
• changes in nerve cells occur in the basal ganglia
• enzyme defect that results in an inadequate production of the neuronal transmitter substance dopamine
• involuntary tremor of limbs when holding still

Question 11

Hydrocephalus

Answer 11

• dilation of the ventricular system usually associated with increased intracranial pressure
• usually due to an obstruction causing cranium enlargement in infants due to lack of complete skull bone fusion

Question 12

Cerebral (Intracranial) Hemorrhages/ 
Hematomas

Answer 12

• collection of blood in the head/brain
• can occur with head injury, even if external injury not present/seen

Question 13

Epidural Bleed (Hemorrhage)

Answer 13

• this bleed happens between the skull bone and the outer most membrane layer, the dura mater
• bleeding within skull, outside of brain

Question 14

Subdural Bleed (Hemorrhage)

Answer 14

• this bleed happens between the dura mater and the arachnoid membrane
• bleeding within skull, outside of brain

Question 15

Subarachnoid Bleed (Hemorrhage)

Answer 15

• this bleed happens between the arachnoid membrane and the pia mater
• bleeding within skull, outside of brain

Question 16

Intracerebral Hemorrhage

Answer 16

• this bleeding occurs in the lobes, pons and cerebellum of the Brian (bleeding anywhere within the brain tissue itself including the brainstem)
• bleeding inside brain tissue

Question 17

Intraventricular Hemorrhage

Answer 17

• this bleeding occurs in the brains ventricles, which are specific areas of the brain (cavities) where CSF is produced
• bleeding inside brain tissue

Question 18

Blood Condition and Density

Answer 18

• acute blood is bright white on CT (once it clots)
• blood become isodense at approx. 1 week
• blood become hypodense at approx. 2 weeks
• unclotted, fresh blood is isodense or hypodense

Question 19

Epidural 
Hematoma/ Hemorrhage

Answer 19

• blood between the skull and dura mater
• most often a skull fracture present
• result of trauma, acute arterial bleeding usually caused by laceration of the medial meningeal artery or its branches
• acute neurological symptoms
• emergency surgical decompression needs to relieve intracranial pressure
• radiographic appearance: CT: bidonnes peripheral high-density lesion, showing midline shift. convex/lens shaped, middle meningeal artery (epi=pie=lemon shape)

Question 20

Subdural Hematoma / Hemorrhage

Answer 20

• result of trauma, venous bleeding most commonly from ruptured veins between the dura mater and the meninges (arachnoid) so into subdural space
• slower bleed (than arterial) with gradual neurologic deficits
• may take time (days, weeks)
  to develop symptoms
• can lead to death

Question 21

Intracerebral Hemorrhage/ Hematoma

Answer 21

• traumatic hemorrhage into the brain parenchyma resulting from shearing forces to intraparenchymal arteries usually at the junction of the grey and white matter
• damage to intima layers which ruptures

Question 22

Intraventricular Hemorrhage

Answer 22

• presence of blood in the ventricles
• can be secondary to intracerebral hemorrhage
• radiographic appearance: CT: homogenous, high density (hyperdense) region within ventricles

Question 23

Subarachnoid Hemorrhage from Trauma

Answer 23

- injury to surface veins, cerebral parenchyma or cortical arteries can produce bleeding into the subarachnoid space and ventricles - radiographic appearance: CT: increased density within the basal cisterns, cerebral fissures and sulci

Question 24

Cerebrovascular Disease

Answer 24

- refers to any process that is cause by an abnormality of the blood vessels or blood supply to the Brian - included in these are strokes, TIAs and aneurysms

Question 25

Subarachnoid Hemorrhage from a Vascular Incident

Answer 25

- major cause of hemorrhage (said form head trauma) is rupture of berry aneurysm in brain - most common locations are origins of the posterior cerebral and anterior communication arteries and the trifurcation of the middle cerebral artery - radiographic appearance: CT: non-contrast scan initially shows hyper density (blood) in the subarachnoid space

Question 26

Aneurysm

Answer 26

- a localized dilation of an artery that most commonly involves the aorta, especially its abdominal portion - due to weakness in wall form decreased elastin and increased collagen production - can rupture/burst - brain aneurysms that burst can cause hemorrhagic stroke - also common in Circle of Willis in the brain

Question 27

Stroke (CVA) 
– Cerebrovascular Accident

Answer 27

- sudden loss of brain function caused by the interruption of flow of blood to the brain (ischemic stroke (blockage) approx. 80%) or the rupture of blood vessels in the brain (hemorrhagic stroke) - interruption of blood flow or the rupture of blood vessels causes neurons in the affected area to die (cerebral infarct) - effects of a stroke depend on location and severity - act fast!

Question 28

Intraparenchymal Hemorrhage/ Intracerebral Hemorrhage/ Hemorrhagic Stroke

Answer 28

- rupture of blood vessel in brain - principle cause of hemorrhage (aside from head trauma) is hypertensive vascular disease (high blood pressure) - can also be a congenital berry aneurysm or an arteriovenous malformation that bursts - ruptured vessel cannot supply blood/oxygen to areas further on, and pooled blood puts pressure on brain

Question 29

Ischemic Stroke

Answer 29

- blockage of vessel in brain with subsequent loss of oxygenation beyond blockage and infarct - CT exam recommended (or MRI), but no CT contrast for stroke evaluation - contrast can cross the disrupted blood brain barrier (BBB) in infarcted area which can lead to increased edema and slower recovery

Question 30

Transient Ischemic Attack (TIA)

Answer 30

- a temporary interruption of blood flow to the brain - from small emboli or stenosis, often coming from carotid bifurcation in neck - symptoms are similar to an ischemic stroke except they are temporary - an important warning sign for increased risk of stroke - likely prescribed low dose aspirin - radiographic appearance: doppler US of neck for diagnosis