Cerebral Disease

Question 1

what are the 6 cortical regions

Answer 1

1. olfactory
2. frontal
3. parietal
4. temporal
5. occipital
6. limbic system

Question 1

cerebrum

Answer 1

cerebral hemispheres + basal nuclei

Question 2

olfactory region

Answer 2

olfactory bulbs + tracts + piriform lobes

ONLY sensory information that does not pass through the thalamus

connects to the limbic system

Question 3

frontal lobe

Answer 3

primary motor cortex + motor association cortex

responsible for behavior, planning, and judgment

Question 4

parietal lobe

Answer 4

dorsal aspect of the cerebrum, caudal to the cruciate sulcus

responsible for somatosensory (touch, pain, temperature, etc)

Question 5

temporal lobe

Answer 5

lateral aspect of the cerebrum

auditory cortex

Question 6

occipital lobe

Answer 6

caudal most aspect of cerebrum

visual cortex

Question 7

limbic system

Answer 7

hippocampus, amygdala, hypothalamus, mammillary bodies, etc

responsible for emotion, memory, instinct

4 Fs - fear, flight, food, repro

Question 8

is cerebral cortex white or grey matter

Answer 8

grey matter

Question 9

is cerebral medulla white or grey matter

Answer 9

both
grey: basal nuclei
white: tracts and fibers

Question 10

caudate nucleus

Answer 10

located along the lateral walls of the lateral ventricles

Question 11

what is the function of cerebral white matter

Answer 11

links the cortical areas with each other and with the subcortical structures

corona radiata, internal capsule, interthalamic adhesion

Question 12

thalamus

Answer 12

part of the brainstem that processes all sensory information EXCEPT olfaction

diseases of thalamus appear similar to cerebral disease

Question 13

medial lemniscal pathway steps

Answer 13

DRG –> nucleus (caudal brainstem) –> decussates –> medial lemniscus –> thalamus –> cerebrum

Question 14

medial lemniscal pathway function

Answer 14

afferent pathway

allows for conscious proprioception on the CONTRALATERAL side

Question 15

corticospinal tract function

Answer 15

cerebrum –> motor neurons

efferent pathway

not very important in animals; cerebral disease does NOT cause primary motor pathway deficits (paresis)

Question 16

rubrospinal tracts function

Answer 16

brainstem –> motor neurons

efferent pathway

responsible for motor activity in animals

Question 17

function of the cerebrum

Answer 17

receives sensory input and plans actions (motor response)

responsible for consciousness, personality, and thought

Question 18

function of the basal nuclei

Answer 18

programs actions

Question 19

brainstem and spinal cord function

Answer 19

executes actions as directed by the basal nuclei

Question 20

signs of cerebral dysfunction

Answer 20

1. seizures
2. altered mentation
3. altered behavior (head pressing, compulsive walking/pacing)
4. circling toward the lesion
5. contralateral postural deficits in TL and PLs
6. contralateral central blindness w/ normal PLRs
7. abnormal posturing (decerebrate)
8. contralateral hemiparesis (mild)
9. +/- cervical pain

Question 21

what maintains cerebral awareness/mentation

Answer 21

reticular activating system (RAS)

passes through brainstem and cerebrum

altered mentation indicates cerebral or brainstem disease

Question 22

mentation types

Answer 22

• BAR: bright, alert, responsive
• obtunded: decreased response to noxious stimuli
• stuporous: response only to noxious stimuli
• comatose: no response to noxious stimuli

Question 23

behavior changes

Answer 23

• changes in normal behavior
• inappropriate behaviors
• aggression
• loss of training
• hyperexcitability
• loss of personality/typical behaviors

ex. head pressing, wide circling, compulsive walking/pacing

Question 24

decerebrate posture

Answer 24

separation of the cerebrum from the brain 1. rigid extension of all 4 limbs 2. opisthotonus (neck extension) 3. comatose mentation

Question 25

postural reactions

Answer 25

proprioceptive positioning (knuckling), hopping, wheelbarrowing, hemiwalking, extensor thrust, visual/tactile placing NOT specific for cerebral disease - occurs with brainstem, spinal cord, and peripheral disease

Question 26

will postural reaction deficits due to cerebral disease be contralateral or ipsilateral to the lesion

Answer 26

contralateral

Question 27

effect of cerebral disease on motor/movement

Answer 27

should have minimal effect may have mild hemiparesis in both the TL and PL on one side (contralateral lesion) NO tetra/paraparesis

Question 28

is central blindness due to cerebral disease on the contralateral or ipsilateral side

Answer 28

contralateral vision loss and menace deficits with NORMAL PLRs

Question 29

what is the hallmark clinical sign of cerebral disease

Answer 29

seizures

Question 30

if signs are symmetric/diffuse - what disease categories are most likely

Answer 30

affect entire cerebrum degenerative metabolic nutritional toxic

Question 31

if signs are lateralized (one sided) - what disease categories are most likely

Answer 31

structural lesions neoplasia inflammatory vascular

Question 32

what are the main diagnostics for cerebral disease

Answer 32

minimum database MRI CSF analysis