Monday, May 12, 2014

Vestibular Disease


 Vestibular Disease

     “Luther’s Strange Problem:  A Case of Vestibular Disease"
                Luther  is a nine year-old Beagle cross that came into Capitol Illini Veterinary Services on a hot July day last summer.  Luther was in a foul mood.  He could not walk straight and when he attempted to do so, he turned in a tight circle to the left.  He couldn’t feel the left-side of his face or blink his left eye.  His nausea was so profound that he vomited numerous times.  Luther’s owners were concerned that he may have had a “stroke?”
                We often see geriatric K9 patients that are examined for what owners believe to be a “stroke.”  Fortunately, not all of these patients have suffered a true vascular accident (“stroke”).   Vestibular disease looks similar to some of the same abnormalities that we see with vascular accidents.  The vestibular apparatus is located within the inner ear.  The function of the apparatus is to provide spatial awareness and aids in keeping a patient oriented and coordinated in movement.  The inner ear is a highly complex space with many nerves and nerve roots in close proximity.  The health of the middle and external ear canals can have a direct influence on vestibular function because all of these structures are linked together.  With this in mind, let’s take a look at some of the other things that were noted during Luther’s initial exam.
                Luther had extremely painful ears.  The external ear canals were very red and irritated.  Ear cytology (looks at different cell populations contained within the ear canals) was performed and it revealed that a very large amount of bacteria was present.  The left and right tympanic membranes (ear drum) appeared to have large amount of debris behind them (this debris was most likely pus).  So how could an ear infection lead to Luther’s condition?  Luther’s ear infection was so severe that it involved all parts of his ear (external/middle/inner).  Not only were the canals affected but a very important nerve, the facial nerve, and his vestibular apparatus were as well.  The facial nerve helps to coordinate movement of the eyelids and other associated facial movements.  The damage to the facial nerve was severe enough to produce Luther’s inability to blink the left eye.  His inability to walk in a coordinated fashion (ataxia) and vomiting (result of motion sickness) was produced by the disruption of the vestibular apparatus by the infection.
                Luther was placed on many types of antibiotics (systemic and topical) for several weeks.  His head-tilt and ataxia resolved relatively quickly.  However, at this writing, his left eye is only able to partially blink.  His owners medicate that eye so that he does not develop a condition known as “dry eye.”   Luther has not had any other complications since the treatment.
                Luther’s vestibular disease had a direct cause- a severe middle/inner ear infection.  There are some cases of vestibular disease that have no discernible cause.  This condition is known as idiopathic vestibular disease (aka “old dog vestibular syndrome).  Idiopathic vestibular disease can begin acutely with clinical signs such as:  ataxia, vomiting, nystagmus (irregular eye movements), circling and a head-tilt.  With appropriate treatment, the condition can resolve within a few hours to weeks.   The bottom-line is this; If your dog or cat (cats can suffer  from vestibular disease too) exhibits any type of neurologic dysfunction bring them in for veterinary care as soon as possible!
Thanks for reading,
Tom Antonini,  DVM
Capitol Illini Veterinary Services
 
               

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