Neurology: Cattle Neurology Flashcards
What should be inspected of surroundings for neurological disease?
- Lead
- Ration- proprotion of conc, silage quality
- Poisonous plants
- Cadavers
What are the following observations signs of?
1. Circling
2. Falling over
3. Head-pressing
- Asymmetrical cortex lesion
- Cerebellum lesion
- ICP/encephalitis
What can be observed about stance and locomotion at a distance?
Stance
* Tremors- rapid contractions
* Spasms- sudden, contractoins of muscles- tetanus
* Spasticity- increased muscle tone- brain stem, spinal cord lesion
Locomotion
* Decreased coordination
* Weakness- paresis or paralysis
What can be inspected on hands on clinical exam of skull and vertebrae?
- Inspection- symmetry, muscle atrophy
- Palpation- pain, crepitus
- Percussion- finger (head), fist (neck)
- Passive movement- bend head/neck in all directions
Reflexes- cerebellum, brain stem, spinal reflex
What is the normal function of the brain stem/cranial nerves
Cerebellum
Spinal cord/peripheral nerves
Brain stem/CN
* cranial nerve functions
Cerebellum
* unconscious control of proprioceptive functions- coordination and smoothing of movements
Spinal cord/peripheral nerve
* Limb strength and movement
What are the 6 steps to neurological exam?
- Mental status
- Cranial nerves
- Gait and posture
- Postural reactions
- Spinal reflexes
- Response to pain
What does mental status tell us?
- Helps differentiate between intracranial and extracranial lesions
- Brainstem- arousal, appear sedated but aware of surrondings
- Thalamocortex- cognititive function, fail to react to environmental stimuli, seperates from herd- head pressing, tilt, circling, blindness
Check for menace response, nasal septum stim (absent if cortical involvement)
What does nasal septum stimulation test?
Tests CN V and thalamocortex
What are the 12 cranial nerves?
Olfactory
Optic
Oculomotor
Trochlear
Trigeminal
Abducent
Facial
Vestibulo-cochlear
Glossopharyngeal
Vagal
Accessory
Hypoglossal
What does the menace response test?
What does the PLR test?
Menace- CN II, VII, cortex, cerebellum
PLR- CN II and III
What is responsible for eye position and movement?
What is responsible for physiological nystagmus?
What is responsible for palpebral reflexes and facial symmetry?
Eye position and movement
* CN III, IV, VI
Physiological nystagmus
* CN III, IV, VI, VII
Palpebral reflex
* CN V, VII
Facial symmetry
* CN VII
What would caus head tilt and pathological nystagmus?
CN VII
- Assess animal facing you- eye should be horizontal
- Check for pathological nystamus- fast phase away from side of lesion
What CN are responsible for food prehension and chewing?
What CN dyfunctions can cause dysphagia and laryngeal problems?
Food prehension and chewing
* XII and V
* Unilateral XII- tongue falls from side of mouth toward lesion
Dysphagia and laryngeal- CN IX and X
What are the three types of ataxia?
- Vestibular
- Cerebellar
- Proprioceptive
How can vestibular ataxia be identified?
- Always head tilt
- Hypermetra
- Hypertonia
- Unilateral cerbellar- animal will lean towards head tilted side
- Bilateral vestibular dysfunction is more subtle
How can cerebeller ataxia be identified?
When is proprioceptive ataxua usually observed?
No proprioceptive defecits or weakness as pathways to and from the limbs to cerebrum are ok
Proprioceptive
Spinal cord disease
Look at foot placements
What spinal reflexes can be used?
Extensor reflex of front limb
* radial nerve dysfunction- dropped elbow
Patellar reflex
* tap patellar tendon and observe extension of stifle
Flexor
* front limbs axillary, median, ulnar,
Musce tone- passively flex and look for symmetry
How is the perineal reflex tested and what does it test?
Gently touch under the tail- downward contraction of the tail and anal sphincter contraction
Pudenal and caudal nerves
How can CSF fluid be taken and analysed?
- Lumbosacral space
- 4 inch spinal needle
- Protein and cytology
- Clear and colourless
What are common clinical signs localisable to cerebrum?
- Opisthotonos- stargazing
- Apparent blindness- intact PLR
- Abnormal mentation
- Change in behaviour
- Aimless wandering
- Seizures
- Abnormal vocalisation
- Ataxia without weakness
- Absent menace
- Hypermetria
What are clinical signs localisable to the vestibular system?
Peripheral and Central:
* Head tilt to lesion side
* Falling/circling/leaning
Just central:
* Nystagmus
* Proprioception defecits on side of lesion
* Depresion/Anorexia
How are the following CN assessed?
1. II
2. V
3. VI
4. VII
5. VIII
6. IX and X
7. XII
- Optic- blindness and abscence of PLR, dilated pupils
- Trigeminal- loss of sensation to head and cornea
- Abducens- ventromedial strabismus, inability to retract globe
- Facial- motor muscles to face- droopy ears/eyelids/lips, unable to blink
- Vestibulo-cochlear- head tilt, circling, leaning/falling
- Glossopharyngeal and vagal- can’t swallow
- Hypoglossal- cannot retract tongue
What clinical signs show reticular activation system, thalamus lesions?
- Depression, altered mentation
- Difficulty regulating body temp
- Depressed respiration
How can clinical signs be localised to spinal cord:
1. C1-C5
2. C6-T2
3. T3-L3
4. L4-L6
5. S1-S3
- Altered head and neck movements- no CN defectits- FL and HL reflexes exaggerated
- Depressed or absent reflexes with reduced muscle tone in the FLs and exaggerated HL reflexes with normal muscle tone in the HLs
- Reflexes in FL normal- HL exaggerated, proprioceptigve defectits in the HLs with ataxia
- Absence of HL reflexes and decreased muscle tone
- Decreased anal tone, loss of sensation to perineal region