ECC ECC Neurological Assessment & Pathology 1 — Questions and Answers
Question 1: Which cranial nerve is assessed when testing a horse's menace response?
- Cranial nerve II (optic) and VII (facial) (Correct answer)
- Cranial nerve III (oculomotor)
- Cranial nerve V (trigeminal)
- Cranial nerve VIII (vestibulocochlear)
Correct answer: Cranial nerve II (optic) and VII (facial)
The menace response tests the afferent optic nerve (CN II) and efferent facial nerve (CN VII) pathway.
Question 2: Ataxia in a horse is best described as:
- Muscle weakness without coordination loss
- Incoordination of voluntary muscle movement (Correct answer)
- Complete paralysis of the hindlimbs
- Abnormal reflex responses only
Correct answer: Incoordination of voluntary muscle movement
Ataxia refers to incoordination of voluntary movements, often indicating spinal cord or cerebellar dysfunction.
Question 3: Which grading scale is most commonly used to score equine ataxia in the US?
- Modified Ashworth Scale
- Mayhew/Nollet Ataxia Scale (0–5) (Correct answer)
- Glasgow Coma Scale
- AAEP Lameness Scale
Correct answer: Mayhew/Nollet Ataxia Scale (0–5)
The Mayhew/Nollet scale grades equine ataxia from 0 (normal) to 5 (recumbent), and is the standard in US equine neurology.
Question 4: A horse that consistently sways when walking in a straight line but improves on a circle most likely has:
- Peripheral nerve damage
- Cervical spinal cord compression (Correct answer)
- Forebrain disease
- Inner ear infection only
Correct answer: Cervical spinal cord compression
Cervical spinal cord compression typically worsens in a straight line and may improve slightly on circles due to altered spinal canal dynamics.
Question 5: The tail-pull test in horses primarily evaluates function of which spinal cord region?
- Cervical (C1–C5)
- Thoracic (T1–T18)
- Lumbosacral (L1–S5) (Correct answer)
- Sacrococcygeal
Correct answer: Lumbosacral (L1–S5)
The tail-pull test assesses lumbosacral spinal cord and nerve root integrity by evaluating resistance to lateral tail displacement while walking.
Question 6: Equine Protozoal Myeloencephalitis (EPM) is caused by which organism?
- Borrelia burgdorferi
- Sarcocystis neurona (Correct answer)
- Streptococcus equi
- Rhodococcus equi
Correct answer: Sarcocystis neurona
EPM is caused primarily by Sarcocystis neurona, a protozoan parasite that damages the central nervous system of horses in North America.
ECC ECC Neurological Assessment & Pathology 1
Which cranial nerve is assessed when testing a horse's menace response?