Focal Brain Disorders

Question 1

what makes up the intracranial tissue volume?

Answer 1

brain parenchyma
blood
CSF

Question 2

what is the most effective compensatory mechanism for volume increase?

Answer 2

CSF shifts: shunt caudally, decrease production, increase absorption

Question 3

is the blood brain barrier disrupted in cytotoxic edema?

Answer 3

not initially

Question 4

what is normal intracranial pressure?

Answer 4

less than 20 mmHg

Question 5

what are the types of brain herniation in dogs due to intracranial disease?

Answer 5

cingulate gyrus herniation
caudal transtentorial herniation
foramen magnum herniation

Question 6

what is transtentorial herniation?

Answer 6

caudal displacement of hemispheres ventral to tentorium cerebelli

Question 7

why is a foramen magnum herniation bad?

Answer 7

compresses medulla

Question 8

what are some clinical signs of foramen magnum herniation?

Answer 8

stupor to coma
tetraplegia
non-responsive and dilated pupils
absent physiological nystagmus
respiratory abnormalities

Question 9

what are some focal space occupying lesions?

Answer 9

dermoid, epidermoid cyst
hematoma, hemorrhage
encephalitis focal, abscessation
neoplasia
granuloma

Question 10

what are two differentials for circling cats?

Answer 10

meningioma
stroke

Question 11

what are some extra-axial bleeding types?

Answer 11

epidural hematoma
subdural hematoma

Question 12

what type of fractures are most common in head trauma?

Answer 12

linear fractures

Question 13

what is there high risk of with basilar skull fractures?

Answer 13

nerve damage or entrapment
CSF otorrhea or rhinoorhea

Question 14

what are some primary brain tumors?

Answer 14

meningioma
astrocytoma
oligodendroglioma
plexus papilloma
pituitary adenoma

Question 15

what are extra-axial tumors mainly?

Answer 15

meningiomas

Question 16

what are common intra-axial tumors?

Answer 16

glial tumors
plexus papilloma

Question 17

what are some differentials for intraventricular tumors?

Answer 17

plexus papilloma or carcinoma
ependymoma
meningioma

Question 18

what are some etiologies of fungal granulomas?

Answer 18

Aspergillus fumigatus
Cryptococcus neoformans
Blastomycosis
Histoplasmosis
Colored fungii

Question 19

what is a stroke?

Answer 19

neurological deficits because of cerebrovascular disease

Question 20

what is ischemia?

Answer 20

reduction in blood flow to a level incompatible with normal function

Question 21

what are some possible causes of stroke in dogs?

Answer 21

often not understood
hypertension, chronic kidney disease, Cushing’s disease, diabetes mellitus

Question 22

what regulates cerebral blood flow?

Answer 22

cerebral metabolic rate
local cerebrovascular autoregulation

Question 23

where does vasogenic edema usually happen?

Answer 23

white matter

Question 24

does vasogenic or cytotoxic edema respond to hyperosmolar IV fluids?

Answer 24

vasogenic edema

Question 25

what is normal mean arterial pressure in the brain and below what is concerning?

Answer 25

80-100 mmHg below 70 mmHg is concerning

Question 26

why is transtentorial herniation a problem?

Answer 26

compresses midbrain and rostral cerebellum

Question 27

what can compressing the medulla lead to?

Answer 27

respiratory compromise death

Question 28

what are possible signs of an acute foramen magnum herniation?

Answer 28

stupor to coma tetraplegia non-responsive and dilated pupils absent physiological nystagmus respiratory abnormalities

Question 29

what is the cushing's reflex?

Answer 29

primary brain ischemia increase in MAP to improve blood flow and oxygen delivery to brain reflex bradycardia

Question 30

is a hemorrhagic stroke from intra-axial or extra-axial bleeding?

Answer 30

intra-axial bleeding

Question 31

what are comminuted fractures like?

Answer 31

fragments aligned depressed bone pieces

Question 32

which antibiotics have good blood brain barrier penetration?

Answer 32

metronidazole enrofloxacin 3rd or 4th generation cephalosporins

Question 33

what is most impacted by cytotoxic edema?

Answer 33

gray matter

Question 34

what are the possible signs of acute brain herniation with transtentorial downwards?

Answer 34

dullness, stupor, coma tetraparesis and ataxia abnormal PLR, anisocoria abnormal physiological nystagmus

Question 35

what are the possible signs of acute brain herniation with foramen magnum?

Answer 35

stupor to coma tetraplegia non-responsive and dilated pupils absent physiological nystagmus respiratory abnormalities

Question 36

what is of concern with intraventricular tumors?

Answer 36

metastatic spread along CSF flow especially with plexus papilloma or carcinoma

Question 37

where are granulomas often with focal GME in the focal form?

Answer 37

brain stem

Question 38

what is the blood supply to the brain?

Answer 38

rostral cerebral artery middle cerebral artery caudal cerebral artery and perforating arteries rostral cerebellar artery caudal cerebellar artery