Neuro01

Question 1

(Circulatory Disorders and Traumatic Injury to the CNS)

Question 2

(2)

(Circulatory Disorders and Traumatic Injury to the CNS)

(Raised Intracranial Pressure)

1. why so susc?
2. four causes?

Answer 2

1. limited potential for expansion
2. focally expanding mass

CSF accumulation

vascular congestion

brain edema

Question 3

(3)

(Circulatory Disorders and Traumatic Injury to the CNS)

(Consequence of the intracranial expanding lesion)

1. local deformity, distortion of brain and reduced volume of what?
2. Internal herniation - results in what?
3. Ischemic Brain Necrosis

what happens here?

Answer 3

1. CSF
2. hemorrhagic infarction of herniated segment or compressed tissue
3. compression of small vessels (esp those from meningeal surfaces) –> if severe get endothelial damage

even if severe is treated, reperfusion causes vasogenic edema (point of no return)

greater degrees of compression –> ischemic brain necrosis

Question 4

(4)

(Circulatory Disorders and Traumatic Injury to the CNS)

(Herniation)

1. supracallosal subfalcine = ?
2. transtentorial = ?
3. foraminal = ?
4. transcalvaris
5. which is most commoon?

Answer 4

1. cingulate gyrus slips beneath
2. occipital cortex slips beneath (compresses midbrain)
3. herniation of cerebellum, compress resp centers in brainstem
4. foraminal

Question 5

(5)

(Circulatory Disorders and Traumatic Injury to the CNS)

(Brain Swelling)

Question 6

(6)

(Circulatory Disorders and Traumatic Injury to the CNS)

(Congestive Brain Swelling)

1. enlargement of the brain resulting in elevated intracranial pressure caused by what?
2. cause?
3. local or generalized?

Answer 6

1. increased of the blood-contating vasculature (cerebrovascular dilation)
2. trauma
3. either

Question 7

(7)

(Circulatory Disorders and Traumatic Injury to the CNS)

(Brain Edema)

1. is an increased brain tissue water content within what?
2. What types (4)?
3. what one is most common?

Answer 7

1. the cell and intercellular space
2. vasogenic, cytotoxic, hypo-osmotic, hydrostatic
3. vasogenic

Question 8

(7)

(Circulatory Disorders and Traumatic Injury to the CNS)

(Brain Edema)

(Maybe due to opening of BBB)

1-3. what three things can cause?

Answer 8

1. tight junction separation
2. ^ vesicular transport (^transendothelial channels)
3. change in structure of endo membrane –> ^ perm

Question 9

(8)

(Circulatory Disorders and Traumatic Injury to the CNS)

(Brain Edema)

(Vasogenic Edema (Vascular leakage))

1. most common
2. loss of function of what?
3. distribution of edema depends on distribution of affected vessels (ex tumor = localized vs. gen = toxins)

(Cytotoxic Edema)

1. what is it?
2. results from damaged what?

Answer 9

2. BBB
3. intracellular fluid accumulation w/ normal vascular perm
4. ATP-dependent ion pumps

(from hypoxia/exotoxin (perfringens))

Question 10

(9)

Answer 10

Question 11

(11)

(Circulatory Disorders and Traumatic Injury to the CNS)

(Brain Edema)

(hypo-osmotic edema - rapid osmolarity shifts)

1-2. from what two?

(Hydrostatic Edema - interstitial Edema)

3. elevated intraventricular hydrostatic pressure that accompanies what?

Answer 11

1. water intoxication
2. salt toxicity (swine, bovine)
3. hydrocephalus

Question 12

(12)

(Circulatory Disorders and Traumatic Injury to the CNS)

(Edema)

eck…

Question 13

(13)

(Intramyelinic Edema (maple syrup urine disease))

1. uncommon, reflecting toxic insult to what?
2. fluid accumulation within what?

Answer 13

1. oligodendrocytes
2. myelin lamella (vacuoles sharply demarcated)

Question 14

(14)

(Hemorrhage)

1. look at pic
2. major consequence due to what?

Answer 14

1. space occupying nature of lesion

Question 15

(15)

(Ischemia)

1. what is it?
2. pathophysiology sim to other tissues
3. What system particularly affected?

why?

regional differences by measuring blood rate - white vs grey?

why else?

most susc neurons?

Answer 15

1. reduction of blood flow to a region
2. nerve system

high metabolic rate

gray higher than white (.65-1.8 vs. .2)

more vulnerable to ischemia (neurons more than glia/vascular)

pyramidal cells in cerebral cortex/hippocampus, purkinje cells in cerebellum (diff in neonate - more brain stem insult)

Question 16

(16)

(Ischemia)

1. time limit that can be tolerated by neurons?
2. causes of diminished tissure perfusion - look at pic

Answer 16

1. 2-3 minutes

Question 17

(17)

(Infarction)

1. death of nervous tissue due to what?
2. gross appearance (red or pale) depends on what?
3. Causes - don’t list them…. but just look - except for this one…

(Feline ischemic encephalopathy)

1. affects what age/sex?
2. acute onset - variable signs - like what?
3. mild improvement over first few days - then remain stable

Answer 17

1 lack of blood supply

2. whether reperfusion takes place
3. any
4. ataxia/circling, seizures, blindness, postural deficits

Question 18

(18)

(Infarction)

(path)

1. usually see what

typically involving territory of what?

2. boundary or boder zone infarcts - are what?

Answer 18

1. unilateral ischemic necrosis

middle cerebral artery

2. distal regions of vascular territories particularly vulnerable

Question 19

(19)

(Spinal cord Infarction - fibrocartilaginous disc emboli)

1. dogs, cats, horse, swine, people
2. acute onset of sudden what?
3. more common in what dogs?

(path)

4. usually in what segments?
5. uni or bi infarct?

grey or white matter?

6. somtimes can localize disc material within arteries/veins (how it gains access in unclear)

Answer 19

2. hemiparesis (weakness of one side of body), flaccid paraplegia (little recovery)
3. chondrodysplastic or large breeds (escessive exercise)
4. lumbar & thoracic
5. uni

both

Question 20

(20)

(Vascular Compression of Spinal cord lesions)

1. principal effect of compressive lesion = ?

extent of injury function of what?

2. what are three types of mass?
3. Since most compression of spinal cord originates in vertebral disc/body - most tend to compress what aspect of cord?
4. What is the hallmark of the response of a nerve fiber to compression?

Answer 20

1. reduction of blood supply

rapidity/degree of compromise

2. herniated intervertebral disc material

epidural abscess/neoplasm

displaced vertebral body (subluxation)

3. ventral
4. Wallerian degeneration

Question 21

(21)

Question 22

(22)

1. Hydrocephalus in a consequence of what?
2. underlying defect is what?

Answer 22

1. structural anomaly (heritable, congenital or post natal)
2. increase in CSF volume reflecting an imbalance in rates of production and resorption

Question 23

(23)

(Types of Hydrocephalus)

(communicating hydrocephalus)

1. CSF may accumulate where?
2. physical alteration of the arachnoids granulations is such that what occurs at a slower rate?
3. these states are uncommon, generally acquired

due to what things?

Answer 23

1. in subarachnoid space and ventricular system
2. CSF absorption
3. vit A def

meningitis/meningoencephalitis

neoplastic involvement of arachnoid villi

Question 24

(24)

(Types of Hydrocephalus)

(Noncommunicating Hydrocephalus)

1. aka?
2. results from what?
3. most common congential defect of what?
4. commonly restricted to what system?
5. For CSF to reach the arachnoid arachnoid villi from its origin in the choroid plexus of the lateral ventricles, efficient passage through 3 foramina/ducts must be unhindered.

what three?

Answer 24

1. internal hydrocephalus
2. decreased CSF resorption
3. dogs (53%exhibit clinical signs)
4. ventricular
5. interventricular foramens

mesencephalic aqueduct

lateral apertures of fourth ventricle

Question 25

(24) (Types of Hydrocephalus) (Noncommunicating Hydrocephalus) (Interventricular Foramen) 1. why is obstruction uncommon? causes are generally what? 2. specifically what masses?

Answer 25

1. large size of opening masses 2. mass involving ipsilateral choroid plexus (neoplasm, cholesterol) mass in vicinity of foramen thalamic neoplasm

Question 26

(26) (Types of Hydrocephalus) (Noncommunicating Hydrocephalus) 1. how susc to alterations? 2. hereidary malformations often result in what? 3. inflammatory lesions where there is ependymal destruction 4. reparative processes restrict diameter of duct (canine parainfluenza virus infection, FIP, mass in vicinity of duct (inflammatory, neoplastic)

Answer 26

1. highly (decreasing CSF flow due to small diameter of the channel and its length) 2. congenital hydrocephalus

Question 27

(27) (Consequences of Hydrocephalus) 1-3. what three?

Answer 27

1. hydrostatic edema 2. herniation 3. atrophy

Question 28

(28) (Trauma) generally a poor prognosis 1-3. why? (3 reasons)

Answer 28

1. neurons don't regenerate 2. hemorrhage --\> ^ cranial Pressure (fixed vol and CSF can't compensate for space occupying lesions) 3. local hemmorhage --\> vasoconstrictive effect on vasculature --\> infarction

Question 29

(29) (Classification of Brain Trauma) (concussion) 1. = ? 2. cause structural changes? reversible? 3. when structural changes are present - what is it?

Answer 29

1. loss of conciousness following transient deformation of axonal processes 2. no yes 3. diffuse axonal injury characterized by axon degeneration and necrosis

Question 30

(29) (Classification of Brain Trauma) (Contusion) 1. strucutral changes? (two types) 2. coup = ? 3. contrecoup = ?

Answer 30

1. YESH 2. head struck by moving (differential acceleartion of cranial vault, CSF, brain) 3. moving head strikes stationary (deceleration of cranial vault, CSF, brain)

Question 31

(31) (classification of brain trauma) (laceration/avulsion) 1. what is it? (due to...) 2 displacement of what? 3. penetrating wound 4. stretching/rupture of what? 5. contusion may have lacertaion components if differential brain-vault accelerations occur where?

Answer 31

1. cutting or tearing of parenchyma (freq involves fracture of bone encasement of CNS) 2. bone fracture margins 4. optic nerve (head trauma in horses where posterior posterior movement movement of the brain against againstthe fixed canalicular portion of the optic nerves results in rupture of the latter) 5. where soft brain parenchyma (young animal) attempts to "move through" a large vessel anchored in dura