LA Neuro Flashcards
1
Q
In Horses, ataxia and paresis…
A
- can be very hard to distinguish and tend to go together
- grouped as a clinical presentation
- but important to differentiate if you are thinking about cerebellar disease as this does not involve paresis normally - but cerebellar disease is VERY uncommon in horses
- where as LMN disease in a horse would likely cause severe flaccid paralysis but not ataxia
2
Q
what next diagnostic test could help you confirm a horse that is ataxic and paretic
A
- standing Rx’s of the horses neck while sedated
- x-rays from the side (often just laterals), some are taking obliques now
3
Q
Brain Lesions in horses…
A
- quite uncommon other than traumatic lesions
4
Q
Myelography in horses
A
- can be done, but it often produces a lot of false negatives and false positives
- cannot really believe results
- only really would do if you were contemplating surgical stabilisation for a cervical vertebral malformation type problem (10-20k just for that Sx)
5
Q
Transcranial Magnetic Stimulation
A
- Transcranial magnetic stimulation, also known as repetitive transcranial magnetic stimulation, is a noninvasive form of brain stimulation in which a changing magnetic field is used to cause electric current at a specific area of the brain through electromagnetic induction
- can be used in horses - but not first choice and really isnt offered in many practices
- in wobblers it takes longer for the current to travel
6
Q
What is Fluphenazine used for in horses?
(phenothiazine drug)
A
- used informally as a long acting sedative in the states (and sometimes in the UK) to calm them down
- in some horses they will have a particular toxic reaction to it –> will show a praying mantis pose (like they are having a trip)
7
Q
Generalized seizures in horses/ponies…
A
- tend to initiate around the head and then spread to the rest of the body
- start with fine quivering of the lip muscles and if the seizure becomes generalised, it spreads over the surface of the head, then the neck, to the whole body
- If there are fasciculations on one side of the body and not the other, it tells you that only one side of the brain is affected
- but because the neurons cross over: it must be the opposite side of the brain
- quite common and hard to deal with due to safety concerns!
- with idiopathic seizures in horses (depending on how many they have had), you can recommend oral phenobarbitone (often a first line Tx for horses with seizures) - but bear in mind how expensive the repetitive Tx is for a horse
- if money is an issue or the insurance can no longer be claimed - euthanasia is a possibility
- mind: the horse should not be ridden for about a year if they are on pehnobarbitone (like for humans dirivng with seizures, need to demonstrate they are capable)
8
Q
Presentation of Acute Grass Sickness in Horses
A
- In acute grass sickness, the symptoms are severe, appear suddenly and the horsewill die or require to be put down within two days of the onset.
- Severe gut paralysis leads to signs of colic including rolling, pawing at the ground and looking at the flanks, difficulty in swallowing and drooling of saliva
9
Q
3 Types of Presentation of Grass Sickness
A
- Hyperacute Colic
- Chronic Insidious Colic
- much more Chronic Low grade weight loss - difficulty eating (dysphagia), muscle fasciculations
- type of toxin that causes a dysautinomia - particularly the parasympathetic neurons that supply the intestinal tract
- hyperacute they get severe colic bc of NG reflux that builds up in their stomach and the stomach can rupture if a NG isnt passed
10
Q
Equine Motor Neuron Disease
A
- Equine motor neuron disease (EMND) is an acquired disorder of adult horses that is strongly associated with an inadequate amount of vitamin E in the diet
- causes low grade, insidious weight loss caused by genralized peripheral neuropathy
- can have muscle fasciculations
11
Q
Presentation of Botulism in Horses
“forage poisoning”
“shaker foal syndrome”
A
- dysphagia
- poor tongue tone (hang out side of mouth)
- progressive problem
- muscle fasciculations sometimes
- Progressive muscle weakness or paralysis and recumbency - the muscles quiver while they stand and then they fall and cannot stand due to weakness
- Weak tongue tone
- Ileus (loss of normal intestinal motility), constipation, and colic;
- Weak eyelid tone
12
Q
Stringhalt in Horses
A
- Stringhalt seems to make horses yank their legs up and halt them there momentarily before taking their next step.
- acute hyperflexion at the level of the hock and stifle and sometimes so severe that the fetlock can come up and strike the abdomen as they are walking
- thought to be a sensory neuropathy of the hindimbs of the leg (unilateral or bilateral)
- thought to be due to trauma commonly when UNIALTERAL- laceration to the distal limb for example that has damaged sensory neurons that partake in the reflex arc
- Toxicity when bilateral
- can actually go away when they are trotting!
- This is the outward sign of neurologic disease, sometimes caused by toxicity, sometimes of unknown origin. If time doesn’t cure it, the prognosis is poor.
- often confused with fibrotic myopathy!! - but in fibrotic myopathy the foot is slapped down to the floor as they walk bc the fibrotic band in the hamstring muscles
13
Q
Bog Spavin
A
- Bog spavin is a term applied to a disorder which applies to the development (or lack of) of the cartilage and bone in the tarsal (or hock) joint.
- musculoskeletal disorder - see a swollen hock joint
- often associated with horses that have Osteochondrosis
- This disorder is most common in young horses and is a result of inflammation which interferes with the development of the joint, either inherited or acquired.
- Bog spavin in horses refers to inflammation of the synovial membrane.
- In this case, the membrane surrounds the tarsus, or hock, joint and can become long term. The inflammation of the hock joint is also known as bone spavin and curb
14
Q
Shivers
A
- Shivers, or equine shivering, is a rare, progressive neuromuscular disorder of horses.
- It is characterized by muscle tremors, difficulty holding up the hind limbs, and an unusual gait when the horse is asked to move backwards.
- Shivers is poorly understood and no effective treatment is available at this time
- affects particularly large breeds of horses
- CS’s: has trouble picking up hind legs and if they do lift the leg above the ground, the leg shivers and shakes, tail head rises
- actually quite common but something owners wont be really aware of
- Issue: these horses have REAL trouble backing up - now more for farriers trying to shoe horses
15
Q
A
- a/d
- minimum width of spinal canal/ maximum width of vertebral physis
- ratio instead of measurement as the measurement would change depending on how the x-ray plate was too the neck
- the farther it is the more the bean diverges and the wider the canal looks
- if the ratio is less than 52% we regard it as significant and there is a high likelihood the horse has Wobblers syndrome
16
Q
acute presentation, unwilling to move the neck, alert
A
- high likelihood of neck fracture
- doesnt want to move the head due to pain
- differential Dx: vestibular disease due to head tilt
18
Q
which CN is affected?
A
- facial nerve
- innervates the muscles of facial expression
- classic in horses: ear droop and muzzle deviation
- if you only had muzzle deviation - sternomastoid foramen is where it leaves and then one branch goes to ear and the other goes across masseter m. to the lip –> lesion must be peripheral if only the muzzle is affected (after the branching to the ear)
- either from injury/kick to side of the face or iatrogenic damage (ex: anesthatize horses for a castration and forget to take off head collar) - will heal though
- here it was a fracture that had caused the damage near the foramen
19
Q
assymetrical ataxia (left more than right)
A
Left cervical spinal cord
20
Q
Horner’s Syndrome in Horses
A
