Page 551 - ONLINE PROCEEDING BOOK WSAVA 2017
P. 551

syndrome which is of unknown aetiology). In this case the vestibular signs may initially be dramatic, but will resolve within days to weeks with no treatment.
Please note that acute cerebellar disease may be confused with vestibular disease. In cases of rostral cerebellar ischemic stroke, signs such as head tilt and nystagmus are very common.
Please note that congenital vestibular disease occur in both cats (e.g. Siamese and Burmese) and dogs (e.g. Dobermann and English cocker spaniel). Congenital nystagmus has been reported in Siamese cats and congenital strabismus have been reported in Siamese and Himalayan cats.
Differentiating central vestibular syndrome from peripheral vestibular syndrome
Lesions of the vestibular system affecting the vestibular nuclei situated in the brainstem can cause a so-called central vestibular syndrome, whereas lesions of the vestibular system affecting the middle and inner ear or the vestibular nerve can cause a so-called peripheral vestibular syndrome. When trying to discriminate between peripheral and central vestibular syndrome, it is of great importance to understand the anatomy of the vestibular system and its adjacent structures.
Peripheral vestibular lesion
With lesions solely affecting the peripheral vestibular
system NO brain stem signs are present. Note however,
An Urban Experience
that signs of Facial nerve (CN VII) dysfunction and Horner’s syndrome (caused by sympathetic nerve  ber de ciency) may be present with lesions of the peripheral vestibular system, as these are travelling in relation
to the petrosal portion of the temporal bone and the tympanic cavity. They may therefore be affected with e.g. in ammatory or infectious disease or neoplasms related to these structures. See table 1.
Central vestibular lesion
A central vestibular lesion should be suspected if clinical signs of vestibular dysfunction
are accompanied by additional signs indicating brain stem involvement. This could be ipsi
-lateral de cits of proprioception, decreased arousal indicating ARAS malfunction, or
lesions affecting or compressing adjacent cranial nerve nuclei or the cranial nerves where
they exit the brain stem (such as the Trigeminal, Facial and Glossopharyngeal nerves).
Please note that Involvement of the Facial nerve can arise from lesions affecting the
central as well as the peripheral vestibular system. See table 1.
Table 1: Clinical signs related to central and peripheral vestibular syndrome
CLINICAL SIGNS
CENTRAL VESTIBULAR
PERIPHERAL VESTIBULAR
Head tilt
+
+
Circling (in small circles), rolling
+/÷
+/÷
Nystagmus
+/÷
+/÷
Postural reactions
+/÷
÷
Consciousness
Decreased arousal
Alert (may however appear confused because of balance problems)
Cranial nerve de cits
CN V (Trigeminal)
CN VII (Facial)
CN XI (Glossopharyngeal)
CN VII (Facial)
Horners syndrome
Rare
+/÷
Diagnostic and therapeutic approach to the vestibular system
Lesions of the vestibular system may be of degenerative, anomalous, metabolic, neoplastic, in ammatory/infectious, traumatic or vascular origin, and should be addressed accordingly with respect to the diagnostic approach
and therapeutic interventions (table 2). A standard work- up includes a clinical inspection of the ear, otoscopy,
a full neurological examination and standard blood
work including haematology and blood biochemistry. For visualization of the middle and inner ear, standard radiographs with lateral, dorso-ventral and open mouth view may be helpful. Computerized Tomography (CT)
551


































































































   549   550   551   552   553