The vestibular system in the body is responsible for maintaining normal balance and position of the head and neck. The vestibular system has two parts, the central portion associated with the brain and the peripheral portion, which is associated with the middle and inner ear.
When a vestibular event occurs, it is usually a sudden onset of loss of balance. The most common clinical signs include head tilt, darting eye movements (nystagmus), circling, rolling, and inability to stand or walk. These signs can often be confused with a seizure.
Whenever your pet is showing signs of a health issue, your first step is to contact your primary care veterinarian. If it is indicated that your pet may suffer from vestibular disease or other serious condition, a veterinary specialist is available at an ExpertVet certified or affiliated hospital.
The causes for vestibular disease range from relatively benign and self limiting to progressive and malignant causes. The most frequent cause is termed geriatric vestibular disease and occurs most commonly in older pets (greater than seven years of age). Geriatric vestibular disease is idiopathic, meaning we can find no distinct cause. Other causes include otitis media (middle ear disease or infection); neoplasia (cancer) in or around the middle and inner ear; toxins (aminoglycoside antibiotics, metronidazole); metabolic disease (hypothyroidism); trauma; stroke or hemorrhage in the central vestibular system; encephalitis/meningitis (inflammation or infection of the nervous system); and neoplasia in the central vestibular system.
Diagnosis of vestibular disease starts with a thorough neurologic and physical exam. It is important to obtain baseline diagnostic tests include blood pressure, CBC, serum biochemical profile, urinalysis, and a thyroid level (T4). In addition, sometimes chest radiographs and abdominal ultrasound may be recommended.
An MRI is the best way to image the brain as well as the middle and inner ear structures. An MRI is recommended in many cases to evaluate for structural disease of the central and peripheral components of the vestibular system. If everything is normal, then a spinal tap is often performed to rule out meningitis or encephalitis.
The first MRI to the left shows a side view of a dog's brain and the large hyperintense circular area at the back of the brain is a brain tumor. This tumor was causing vestibular signs. This is an example of central vestibular disease.