MNP - cranial nerves

Question 1

The aspect of caudal digastricus muscle is associated with the outcome in facial paralysis: true or false?

Answer 1

True

Muscle atrophy (89%), hyperintensity in T2W (89%), and pre-contrast T1W (79%) images, as well as contrast enhancement of the affected muscle (74%) and affected facial nerve (47%).

There was no statistically significant correlation between atrophy or enhancement of the affected caudal portion of the digastric muscle nor between enhancement of the affected facial nerve and outcome.

Hyperintensity both in T2W images and precontrast T1W images was significantly correlated with a worse prognosis

Question 2

In dogs with idiopathic, oculomotor neuropathy, what statement IS false?

1. Approximately half of all animals improved over time
2. Improvement concerned only external ophthalmoparesis
3. Improvement was noted both for external and internal ophthalmoparesis
4. The majority of cases presented nerve enlargement in MRI

Answer 2

3

Question 3

DDx dropped jaw

Answer 3

Idiopathic trigeminal neuritis (most common)
Trauma
Rabies
Lymphoma
Neospora caninum
Rickettsial vasculitis
Hypothyroid neuropathy
Idiopathic polyneuritis

Question 4

DDx trismus

Answer 4

Masticatory muscle myositis
Polymyositis
Extraocular myositis
Muscular dystrophy
Tetanus
Temporomandibular joint luxation
Craniomandibular osteopathy
Retrobulbar abscess
Foreign body

Question 5

DDx laryngeal paralysis

Answer 5

Degenerative: GOLPP

Anomalous: genetic, polyneuropathy complex

Metabolic: hypothyroidism, hypoadrenocorticism, toxic (Pb, organophosphorus)

Neoplastic: thymoma, lymphoma, thyroid carcinoma

Inflammatory: polymyositis, myasthenia, polyneuritis

Traumatic: surgery (ventral slot), wound

Question 6

What are the clinical features associated with trigeminal nerve tumor?

Answer 6

Enlarged trigeminal nerves with marked homogeneous contrast enhancement and a mass effect on the brainstem or outside the cranial cavity along the nerve.

Unilateral clinical (also the case for neuritis)
Sensory impairment (also the case for neuritis)
Ipsilateral noninfectious middle ear effusion (only neoplasia, 33%)
Significantly older than dogs with neuritis and ITN.

Question 7

Contrast enhancement of cranial nerves VII and/or VIII on MRI was associated with a decreased chance of resolution of the clinical signs: true or false?

Answer 7

True

Question 8

Which ocular abnormalities can we see in optic nerve hypoplasia? Which breed has been associated with this condition?

Answer 8

Lack of neurons in ganglionic layer of the retina and atrophy of the optic nerve, possible retinal dysplasia or retinal detachment -> blind, mydriatic and absent direct PLRs.
Miniature poodle