Cerebral Disease Flashcards
what are the 6 cortical regions
- olfactory
- frontal
- parietal
- temporal
- occipital
- limbic system
cerebrum
cerebral hemispheres + basal nuclei
olfactory region
olfactory bulbs + tracts + piriform lobes
ONLY sensory information that does not pass through the thalamus
connects to the limbic system
frontal lobe
primary motor cortex + motor association cortex
responsible for behavior, planning, and judgment
parietal lobe
dorsal aspect of the cerebrum, caudal to the cruciate sulcus
responsible for somatosensory (touch, pain, temperature, etc)
temporal lobe
lateral aspect of the cerebrum
auditory cortex
occipital lobe
caudal most aspect of cerebrum
visual cortex
limbic system
hippocampus, amygdala, hypothalamus, mammillary bodies, etc
responsible for emotion, memory, instinct
4 Fs - fear, flight, food, repro
is cerebral cortex white or grey matter
grey matter
is cerebral medulla white or grey matter
both
grey: basal nuclei
white: tracts and fibers
caudate nucleus
located along the lateral walls of the lateral ventricles
what is the function of cerebral white matter
links the cortical areas with each other and with the subcortical structures
corona radiata, internal capsule, interthalamic adhesion
thalamus
part of the brainstem that processes all sensory information EXCEPT olfaction
diseases of thalamus appear similar to cerebral disease
medial lemniscal pathway steps
DRG –> nucleus (caudal brainstem) –> decussates –> medial lemniscus –> thalamus –> cerebrum
medial lemniscal pathway function
afferent pathway
allows for conscious proprioception on the CONTRALATERAL side
corticospinal tract function
cerebrum –> motor neurons
efferent pathway
not very important in animals; cerebral disease does NOT cause primary motor pathway deficits (paresis)
rubrospinal tracts function
brainstem –> motor neurons
efferent pathway
responsible for motor activity in animals
function of the cerebrum
receives sensory input and plans actions (motor response)
responsible for consciousness, personality, and thought
function of the basal nuclei
programs actions
brainstem and spinal cord function
executes actions as directed by the basal nuclei
signs of cerebral dysfunction
- seizures
- altered mentation
- altered behavior (head pressing, compulsive walking/pacing)
- circling toward the lesion
- contralateral postural deficits in TL and PLs
- contralateral central blindness w/ normal PLRs
- abnormal posturing (decerebrate)
- contralateral hemiparesis (mild)
- +/- cervical pain
what maintains cerebral awareness/mentation
reticular activating system (RAS)
passes through brainstem and cerebrum
altered mentation indicates cerebral or brainstem disease
mentation types
- BAR: bright, alert, responsive
- obtunded: decreased response to noxious stimuli
- stuporous: response only to noxious stimuli
- comatose: no response to noxious stimuli
behavior changes
- changes in normal behavior
- inappropriate behaviors
- aggression
- loss of training
- hyperexcitability
- loss of personality/typical behaviors
ex. head pressing, wide circling, compulsive walking/pacing
decerebrate posture
separation of the cerebrum from the brain
- rigid extension of all 4 limbs
- opisthotonus (neck extension)
- comatose mentation
postural reactions
proprioceptive positioning (knuckling), hopping, wheelbarrowing, hemiwalking, extensor thrust, visual/tactile placing
NOT specific for cerebral disease - occurs with brainstem, spinal cord, and peripheral disease
will postural reaction deficits due to cerebral disease be contralateral or ipsilateral to the lesion
contralateral
effect of cerebral disease on motor/movement
should have minimal effect
may have mild hemiparesis in both the TL and PL on one side (contralateral lesion)
NO tetra/paraparesis
is central blindness due to cerebral disease on the contralateral or ipsilateral side
contralateral vision loss and menace deficits with NORMAL PLRs
what is the hallmark clinical sign of cerebral disease
seizures
if signs are symmetric/diffuse - what disease categories are most likely
affect entire cerebrum
degenerative
metabolic
nutritional
toxic
if signs are lateralized (one sided) - what disease categories are most likely
structural lesions
neoplasia
inflammatory
vascular
what are the main diagnostics for cerebral disease
minimum database
MRI
CSF analysis
