18. Examination of the nervous system 4. Flashcards
What does Hyposomia mean?
partial loss of smell
What does anosomia mean?
complete loss of smell
How do you examine N.olfactorius?
– Use strong stimulatory objects/materials – Use food – Exclude vision (→II.!)
What does N.olfactorius do?
smelling
What does N.opticus do?
vision
Test for vision:
– blindness: amaurosis – falling cotton test (tracking) – leading the animal to objects – pupillary light reaction (+III.) – threat/menace reflex (+VII.) – optical placing test
What is threat/menace reflex?
Fast hand gesture against eye, avoid air current and sensory hairs, animals should blink.
what is Anisocoria?
uneven size of pupils
What is mydriasis?
dilation of pupils
What is miosis?
constriction of pupils
Which nerves do we examine when we examinate the position and movements of the eyeballs?
n. oculomotorius (III.), n. trochlearis (IV.) and n. abducens (VI.)
Examination of the position and movement of the eyeballs, what is the normal reaction?
the eyeballs move simultaneously
and their axis are parallel
Explain physiological nystagmus:
moving of head elicits involuntary eye movements (+VIII.)
fast phase toward direction of movement
Explain pathological (spontaneous) nystagmus:
– Horizontal
– Vertical
– Rotatory
What happens when the animal have a III.paralysis?
strabismus divergens
ventrolateralis
What happens when the animal have a IV.paralysis?
strabismus medioventralis
What happens when the animal have a VI.paralysis?
strabismus convergens
(medialis)
+ exophtalmus
What are strabism?
- Abnormal position of the eyeballs (uni- or bilateral)
- They are not parallel
What does N.Trigeminus do?
Feeling of face, motor and sensory
What is the motor function of the N.trigeminus?
– Innervation of m. temporalis and masseter:
prehension of food, drinking and chewing
– Paralysis: sagging lower jaw – exclude rabies!
– Tic: repeated contractions of chewing muscles
(e.g. distemper)
– Trismus: tonic spasm of chewing muscles
(e.g. tetanus, myositis)
Which reflexes do we check when we check the N.trigeminus?
Corneal reflex and palpebral reflex, checking testing lateral and medial canthus.
what is the sensory function of N.facialis?
Gustatory fibers to rostral 2/3 of tongue
What is the motor function of N.facialis?
– Nasal plane, lips, eyelids, mimic muscles, pinnae
– Threat reflex (+II.)
– Palpebral reflex (+V.)
– Corneal reflex (+V.)
What kind of paralysis do the animal get when N.facialis is paralysed?
- Nasal plane is drawn toward healthy side (unilateral)
- Sagging of upper eyelid(s): ptosis
- Sagging of lip(s)
- Sagging of ears (central damage)
Explain the disfunction of the vesticular nerve?
It is called vestibular syndrom: • Ipsilateral head tilt • Ipsilateral leaning and falling • Nystagmus: mostly horizontal, slow phase toward side of lesion • Mental state unaffected
How do we examine the hearing?
– Calling, clapping outside vision field
What is anacusis?
deafness
What does N. glossopharyngeus (IX.) and n. vagus (X.) innervate?
Innervation of pharynx, larynx – Sensory: IX. (+ caudal 1/3 of tongue) – Motor: X.
What happens if N. glossopharyngeus (IX.) and n. vagus (X.) is paralysed?
– Swallowing problem (dysphagia)
– Paralysis laryngealis
• Unilateral: altered vocalization
• Bilateral: inspiratory dyspnoe
How do we check the swallowing reflex?
– With water – Feeding – Touching base of tongue (Rule out rabies!) – External compression of throat
What does N.accesorius innervate?
– M. trapesius
– M. sternocephalicus
– M. brachiocephalicus
How is paralysis of N.accessorius visible?
– Sagging of head
– Atrophy of muscles on neck, shoulder
what is N-hypoglossus responsible for?
Responsible for protruding and retracting the tongue
How is paralysis of the N.hypoglossus visible?
– Bilateral lesion: prolapse of the tongue
– Unilateral lesion: contralateral deviation of the tongue
How do we examine the n.hypoglossus?
– Protrusion and withdrawal of tongue after swallowing
– Strength of retraction after grasping the tongue
