SAM Sx 2 Neuro
Terms in this set (123)
What is the difference between reflex & reaction?
Reflexes are mediated by the grey matter and require no cortical integration; even animals with spinal cord lacerations will have reflexes
Altered mentation occurs with dz of central, peripheral, both
Awake but not alert to surroundings; not interested in normal stimuli
Animal is dull and slow to respond but will respond appropriately
Animal is unresponsive to normal stimuli but can be roused with a strong stimuli (such as a pinch)
A state of unconsciousness in which the animal cannot be roused, even with noxious stimuli
A wide-based stance is most commonly observed in what 2 abnormalities?
What is decerebrate rigidity?
Decerebrate is characterized by rigid extension of all four limbs, often with opisthotonus
It indicates a brainstem lesion; animals in this state are stuporous or comatose
What is decerebellate rigidity?
Decerebellate is opisthotonus with rigid extension of thoracic limbs but hip flexion of the pelvic limbs it
Indicates an acute cerebellar lesion; consciousness not impaired
What are the lower motor neuron signs
hyporeflexia and decreased muscle tone
Pure LMN disease typically has what unique features?
Absence of ataxia (but animal is weak)
Rapid atrophy of muscles
What abnormal reflex is present in UMN lesions?
This form of ataxia is characterized by in-coordination, crossing over of paws/limbs, knuckling, and scuffing. It is due to a loss in proprioceptive pathways.
Sensory (aka general proprioceptive) ataxia
Describe vestibular ataxia
Characterized by head tilt, leaning, falling to one side, and wide-based stance
Due to loss of vestibular pathways.
What feature helps to distinguish general proprioceptive ataxia from cerebellar ataxia?
Movements are hypermetric (high-stepping, very exaggerated). Tremors often present.
Typically no scuffing or knuckling. There is NO weakness associated with cerebellar disease
Describe intention tremors. What disease process are they associated with?
A low-frequency tremor that worsens with movement (typically with initiation)
Associated with cerebellar dysfunction
What is a physiologic tremor
A fine tremor that is most dramatic during weight-bearing. It is not aggravated by movement
Causes are physiologic (hypothermia, toxins, etc.)
What is a parkinsonian tremor
A Parkinsonian tremor is present constantly, including at rest. It is not commonly seen in animals
Striking patellar ligament results in flexion? or extension? of distal limb.
the patellar ligament reflex tests which nerve arising from where
Striking the cranial tibial m. results in flexion? or extension? of hock
The cranial tibial reflex tests which nerve arising from where
peroneal brr of sciatic n.
Striking the ______________ results in contraction of semimembranosus/teninosus mm.
Striking the calcanean tendon tests which nerve arising from where
tibial brr of the sciatic n. L7-S1
Striking the_______ results in contraction of the biceps brachii & brachialis mm.
Striking the biceps tendon tests which nerve arising from where
musculocutaneous n. C6-C8
Striking the triceps tendon results in flexion? or extension? of the elbow.
Striking the triceps tendon tests which nerve arising from where
radial n. C7-T1
Striking the extensor carpi radialis m. results in ------ of the carpus
Striking the extensor carpi radialis m. tests which nerve arising from where
radial n. C7-T1
Do withdrawal reflexes require cortical awareness?
No; locally mediated reflex arc
Describe the withdrawl reflex in the pelvic limb - what nerve is being tested and where does it arise from?
Tests sciatic n
Arises from L6-S1
Describe the withdrawl reflex in the thoracic limb - what nerve is being tested and where does it arise from?
ALL nerves of the forelimb are tested in this reflex
Primarily arises from C6-T1; small contributions from C5 & T2
The perineal reflex tests which nerve arising from where
name to first 6 cranial nerves
name the last 6 cranial nerves
review cranial nerve tables-- ppt
What cranial nerve deficits would you expect to see with a forebrain lesion?
CN I (with cerebrum)
CN II (with diencephalon involvement)
A medial strabismus and abnormal eye movements indicate lesions in CN's ___ & ___. This is consistent with a lesion in what area?
III, IV---Midbrain of brainstem (Mesencephalon)
Lesions of the pons primarily result in CN ____ deficits
What signs might you see with CN V deficits
Loss of sensory input mediated by trigeminal ( = loss of blink when touched, loss of corneal reflex)
Decreased jaw tone or atrophy of mm. of mastication
Problems with cranial nerves VI through XII indicate a lesion in what area of the brainstem?
review UMN/LMN tables in ppt
How can reflexes help distinguish central / intracranial lesions from peripheral?
Reflexes are typically NORMAL with intracranial lesions
A head tilt to one side and postural reaction deficits on the contralateral side in an obtunded animal points to what neuro localization?
What feature of cerebellar disease is NOT present? (Helps distinguish from other intracranial areas)
Animals are NOT weak; mentation is normal
What is the intracranial neuro localization for a head turn vs. a head tilt?
Head turn = Forebrain
Head tilt = Brainstem or middle/inner ear
Bladder storage is under control of the sympathetic or? parasympathetic nervous system, located in the ____________ region of the spinal cord.
Bladder storage is under control of the __________ n, arising from L1-L4 in dogs & L2-L5 in cats.
The B receptor stimulates relaxation of the ________, resulting in urine storage. a receptor stimulation constricts the _______.
detrusor m., internal urethral sphincter
Somatic innervation of the bladder is from _________ n., which arises from _____.
pudendal S1- S3
During urination, the ______ n. (from S1-S3) stimulates contraction of detrusor to evacuate urine
Micturition is marked by contraction and relaxation of which muscles
contraction of the detrusor m. and relaxation of the internal urethral sphincter
Which region of the spinal cord controls micturition
During normal filling of the bladder, which predominates-- sympathetic or parasympathetic
This facilitates the _______ n. to contract the external sphincter and the _________ n. to contract the internal
Inhibition of the _____ n. allows the detrusor m. to relax
During normal micturition, which predominates-- sympathetic or parasympathetic
During micturition, sensory branch of ______ n. sends ascending information to what 3 intracranial areas?
Brain stem, cerebellum, cerebrum
A signal to urinate is sent via LMN <or> UMN pathways in pons & medulla. This descends via reticulospinal tracts through spinal cord.
Inhibition of what nerves relax the detrusor m., internal sphincter, and external sphincter (respectively)?
Hypogastric n. (detrusor & internal sphincter)
Pudendal n. (external sphincter)
Facilitation of ______ n. contracts the detrusor
Lesions in what areas would result in neurologic bladder issues?
Cerebral or cerebellar (RARE), NM disease, detrusor-urethral dyssnergia
Urination problems could be due to primary bladder pathology - give 3 major (broad category) examples
Mechanical outflow obstructions (stones, neoplasia, inflammation, etc.)
urinary problems may be behavioral or pharmacological. What 3 drug categories may cause a problem?
Opiates, anti-depressants, anti-cholinergics
Urine dribbling, flaccid bladder that is easily expressed but difficult to empty due to poor tone and small volume for how large it is are all signs of what type of dysfunction
LMN dysfunction of the bladder indicates a lesion where?
What 2 nerves of the bladder are affected by a lesion in S1-S3 (LMN)
pelvic and pudendal nn
UMN dysfunction of the bladder indicates a lesion where?
lesion cranial to L7
Urination can occur but is often incomplete and bladder is difficult to express due to increased tone. Dysfunction is due to lack of higher integration-- this indicates what type of dysfunction
What are the 3 major goals of bladder management
Prevent infection, prevent detrusor atony, prevent urine scald
What drugs are given to relax the internal urethral sphincter
What drug is used to relax the external urethral sphincter
Which drugs are not typically used for neurologic disorders of the bladder
PPA and estrogen-- these both increase sphincter tone and we are more concerned to make sure it will empty
Bethanechol also increases tone-- can be used if you treat with phenoxy or prazosin first
What are the 4 main differentials for diffuse, symmetric signs?
Focal, lateralized differentials?
Multifocal intracranial disease typically has 3 differentials to consider:
Metastatic neoplasia, infectious, vascular
give the 3 primary differentials to consider for Peracute onset (minutes - hours) for intracranial disease
Vascular, traumatic, other more specific dz
give the 3 primary differentials to consider for Acute onset (days up to 1 week) for intracranial disease
Infectious, traumatic, other
give the 3 primary differentials to consider for Chronic onset (gradual over weeks to months) for intracranial disease
Neoplasia, degenerative, others
give the 3 primary differentials to consider for Static, non-progressive for intracranial disease :
Vascular, congenital/anomalous, trauma
give the 3 primary differentials to consider for Progressive dz for intracranial disease
Neoplasia, infectious, degenerative
What non-invasive, readily available test may help rule in infectious or inflammatory disease?
Chorioretinitis is a sign of infectious/inflammatory disease
What is the purpose of thoracic radiographs in neuro cases?
What is the prognosis for congenital hydrocephalus
good as long as they don't get head trauma
how can you treat hydrocephalus
pred, omeprazole to reduce CSF production
What is the likely cause of Feline ischemic encephalopathy
what are the typical clinical signs of Feline ischemic encephalopathy
asymmetric, seizures, circling-- forebrain, acute, non-progressive
Which seizure meds inhibit GABA
Benzodiazepines, phenobarbital, potassium bromide, Keppra
Which seizure meds are Na/Ca channel blockers
which seizure med inhibits GABA and inactivates Na channels
Which seizure meds are used for emergency treatment
what are the most common therapeutic seizure meds
phenobarbital, potassium bromide
What is the clinical manifestation of high intracranial pressure
low HR in spite of high BP and ventricular arrythmia
post head trauma, describe the appearance of pupils in order of fair to grave prognosis
Unilateral mydriasis & unresponsive PLR (guarded)
Bilateral pinpoint pupils (guarded to poor)
Bilateral mydriasis, unresponsive PLR (grave prognosis)
What procedures should be avoided in cases of increased ICP?
What anti-inflammatory drugs should be avoided in case of ICP?
What is the recommended treatment for cases of increased ICP?
What is the purpose of analgesics for ICP therapy?
Pain contributes to increased ICP
What clinical features are very characteristic of cerebellar disease?
Uncoordinated movements (usually very exaggerated, such as high stepping)
Why cerebellar dz present with vestibular signs and how do these look?
Paradoxical; animals tilt/circle toward side of lesion. Due to long tract relays at level of cerebellum
Cerebellar hypoplasia can occur when kittens are infected in utero with what?
What are the signs of cerebellar abiotrophy
progressive cerebellar signs
Is it possible to rule out central vestibular disease?
Is it possible to rule out peripheral vestibular disease?
yes: vertical nystagmus, positional nystagmus, proprioceptive deficits, CN other than VII and Horners affected, altered mentation, and paradoxical dz are all signs specific to central dz
What are the 2 major differentials for peripheral vestibular disease?
Idiopathic vestibular disease
What are the major differentials for central vestibular disease?
Drug toxicity (Metronidazole)
What are the main differentials for peracute onset spinal cord disease?
Vascular, traumatic (type I IVDD, unstable fractures)
What are the main differentials for Acute onset (days, up to a week) spinal cord disease?
What are the main differentials for Chronic (gradual over weeks to months) spinal cord disease?
Neoplasia, degenerative, infectious
What are the 3 main differentials for static spinal cord disease?
What are the 3 main differentials for progressive spinal cord disease?
Traumatic (over days, but rarely longer)
What is the typical signalment in Type I IVDD?
Chondrodystrophic breeds (Dachshunds, Pekingese, Corgi, etc.)
Degeneration occurs within first 2 years of life
What is the typical signalment in Type II IVDD?
Non-chrondrodystrophic breeds, especially German Shepherds
Occurs late in life
How do the pathogeneses differ between Types I & II IVDD?
Type I nucleus is invaded by cartilage and dehydrates, weakens & ruptures-- painful and acute
Type II disc dehydrates first and disc bulges but does not usually rupture
What are the key features of fibrocartilagenous embolism?
Peracute onset; painful within first few hours
What is the highly characteristic gait associated with Wobbler's syndrome (compression of cervical spine)?
Two-engine gait (long strided pelvic limbs, short steps in front)
Discospondylitis effects young to middle aged medium to giant breed dogs. Because this may have infectious origins, what clinical signs can help you differentiate this from other diseases?
Systemic signs (fever, inappetance, depression) - is this painful?
Extremely! Especially right around site of infection
What are the main differentials for acute onset polyneuritis?
Coonhound or tick paralysis
What is the ONLY condition that has CSF with increased protein but no WBCs and what is this called?
Coonhound paralysis; CSF findings known as albuminocytologic disassociation
This typically affects large breed, middle-aged to older dogs. It results in generalized weakness that may wax/wane with exercise and tends to respond to prednisone:
What are the key clinical pathology findings in cases of ischemic neuromyopathy (saddle thrombus)?
CK elevated & hyperkalemia
What are the 3 main (general) differentials for multifocal disease?
Neoplasia, infection, inflammation