Abnormal Neuro Exam Part 2 Flashcards
Spinal reflexes will increase or stay the same with ….
UMN disease
spinal reflexes will decrease with …
LMN disease
Type of muscle atrophy associated with UMN disease?
disuse atrophy
Type of muscle atrophy associated with LMN disease
neurogenic atrophy (rapid)
Regarding the cutaneous trunci reflex - if there is a cut off….
lesion is 1-2 spinal cord
segments cranial to cutoff
Regarding the cutaneous trunci reflex - If absent on one side
regardless where you
pinch ….
there is an efferent problem on that side (C8-T1 spinal cord segments and nerve roots, lateral thoracic nerve, or cutaneous trunci mm)
Optic Nerve Dysfunction (CN2) (3 signs)
- Menace deficit - avisual - Absent / decreased PLR - Mydriasis
Occulomotor Nerve Problem
CN3) (3 signs
-ptosis, ventrolateral resting strabismus, mydriasis (parasympathetic dysfunction)
4 cardinal signs of Horner’s syndrome
Ptosis
Elevated 3rd eyelid
Enopthlamos
Miosis (anisocoria)
Neural pathway associated with Horner’s syndrome
- 1st order neuron: hypothalamus down brain
stem down spinal cord - 2nd order neuron: T1-2 spinal cord segments
travels cranially with vagosympathetic trunk
up the neck - 3rd order neuron: cranial cervical ganglion
thru the tympano-occipital fissure into the inner
ear travels into the ventral floor of the brain
exit skull thru orbital fissure
1. dilator muscles of the pupil
2. periorbital smooth muscles
3. third eyelid
4. eyelid (muller’s muscle)
5. blood vessels within and around the eyes
Causes of miosis
constricted pupil
-Primary ocular
- corneal ulcer
- uveitis
-Spastic pupil syndrome – -FeLV / FIV
Increased parasympathetic - pilocarpine, cerebrocortical disease
decreased sympathetic - Horner’s syndrome
Causes of mydriasis
Decreased parasympathetic - atropine, CN3 dysfunction Increased sympathetic - phenylephrine - Primary ocular - blindness - glaucoma - iris atrophy -- Cerebellar disease
Trochlear Nerve Dysfunction
(CN4) - often seen with what clinical sign?
Contralateral
ventromedial resting
strabismus
Contralateral ventromedial resting strabismus is seen in the dog in what part of the eye
fundus of the eye
Contralateral ventromedial resting strabismus is seen in the cat in what part of the eye
slit pupils