Differential Diagnosis and Management of Cranial Nerve Abnormalities

SummaryA 2‐year‐old Warmblood gelding was presented with a history of bilateral feed material coming from the nostrils secondary to dysphagia, coughing and impairment of physical development, since purchase at 6 months of age. Endoscopy of the right guttural pouch was unremarkable; however, in the left guttural pouch, a distended (aneurysm), pulsating, tortuous elongated internal carotid artery (ICA) was observed. Computed tomography revealed that in the dorsal aspect of the medial compartment of the left guttural pouch adjacent to the jugular foramen, the ICA turned anti‐clockwise creating a small loop of 1 cm diameter. This loop had a faint linear, soft tissue attenuating connection to the caudodorsal wall of the guttural pouch and was slightly larger in diameter compared to the right ICA. A malformation of the left ICA was diagnosed, most likely congenital. A secondary compression and neuropathy of one or multiple nerves of the associated lower cranial nerves in the neurovascular plica (IX, X) was suspected explaining the clinical signs of dysphagia. The slightly larger diameter of the left ICA could represent congestion of the vessel or an early aneurysm formation. Based on these findings, endovascular balloon occlusion (nondetachable balloon) of the left ICA was performed to relief the compression on the affected nerves. The occlusion of the ICA resolved the clinical signs within 7 weeks after surgery.

Section: Discussionmentioning

confidence: 99%

Neurologic deficits and surgical treatment in a horse affected with internal carotid artery tortuous elongation

Rijkenhuizen,

Kaske,

Rikart

et al. 2023

“…Central nervous system neoplasia is uncommon in horses, with a prevalence of less than 2% of horses presenting with neurologic disease (Aleman et al, 2018). Few cases of ependymomas, choroid plexus tumours, glioblastoma multiforme, ganglioglioma, melanomas, adenomas, meningiomas and ganglioneuromas have been reported (Aleman et al, 2018; MacKay, 2015). No breed, age or sex predisposition has been described in horses.…”

Section: Discussionmentioning

confidence: 99%

“…The trigeminal nerve is responsible for sensory innervation of the face, motor innervation of masticatory muscles and palpebral reflex (Furr & Reed, 2015c; MacKay, 2015). Therefore, right CN‐V paralysis was suspected in this case, and differential diagnoses included the following: head trauma, nerve compression from an intracranial or extracranial mass, and less likely temporohyoid osteoarthropathy (THO), bacterial infection (guttural pouch empyema and bacterial meningitis) and toxicosis, although additional signs of central nervous system (CNS) or other CN lesions would be expected (Furr & Reed, 2015c).…”

Section: Case History and Clinical Findingsmentioning

confidence: 99%

Otopathy secondary to trigeminal schwannoma in a Quarter Horse

Lemonnier

Dorso

Tricaud

et al. 2022

Otitis media secondary to trigeminal nerve (CN-V) paralysis is described in dogs and humans but not in horses. An 18-month-old Quarter Horse colt was presented with history of mastication difficulties and a nonhealing corneal ulcer. Clinical findings were consistent with paralysis of the right CN-V. Computed tomography imaging showed otopathy media and a mass at the root of the CN-V. The colt was euthanised due to poor prognosis. Postmortem magnetic resonance imaging showed enlargement of the right CN-V which was slightly hyperintense on T2W. Histopathology of the mass revealed fusiform tumoural cells, positive on vimentin-and S100 immunohistochemistry, consistent with a schwannoma. Otitis media was presumed secondary to CN-V paralysis and denervation of the right tensor veli palatini muscle involved in opening of the Eustachian tube. This is the first case of trigeminal schwannoma and secondary otopathy media described in a horse, which highlights the importance of imaging in investigating trigeminal nerve paralysis.

“…Clinical signs related to vestibular dysfunction are usually unilateral and commonly include leaning or ataxia, head tilt, pathological nystagmus and positional ventrolateral strabismus (De Lahunta & Glass, 2014; Mayhew & MacKay, 2022) In the absence of other signs of central nervous system dysfunction such as obtundation, weakness or conscious proprioceptive deficits, peripheral vestibular syndrome should be suspected (Rush et al, 2008). Peripheral vestibular dysfunction is often accompanied by facial nerve paralysis due to the close anatomical association of these structures (Gonçalves et al, 2015; MacKay, 2015).…”

Section: Introductionmentioning

confidence: 99%

Suspected idiopathic vestibular syndrome in the horse: Eight cases (2014–2021)

Wilson

Gonçalves

Carslake

et al. 2023

SummaryA descriptive case series of the presentation, diagnosis, treatment and outcome of eight horses presenting to a UK equine veterinary hospital with suspected idiopathic peripheral vestibular syndrome over a 7‐year period (2014–2021). Idiopathic vestibular syndrome in the horse causes unilateral clinical signs including; ataxia, nystagmus, strabismus and a head tilt. Diagnosis is aided by neurological examination, endoscopy of the upper airway and cross‐sectional imaging (i.e. magnetic resonance imaging and computed tomography). This case series indicates that horses with this condition can make a full recovery with return to ridden exercise. Treatment with anti‐inflammatory medication did not appear to influence outcome.