The Vestibular System

What is the vestibular system?

Based on the Neuroscience book by Purves D. the vestibular system provides the sense of balance and the information about body position that allows rapid compensatory movements in response to both self-induced and externally generated forces.

The peripheral portion of the vestibular system is a part of the inner ear that acts as a miniaturized accelerometer and inertial guidance device, continually reporting information about the motions and position of the head and body to integrative centers located in the brainstem, cerebellum, and somatic sensory cortices. Although we are normally unaware of its function, the vestibular system is a key component in both postural reflexes and eye movements. If the system is damaged, balance, control of eye movements when the head is moving, and sense of orientation in space are all adversely affected. These manifestations of vestibular damage are especially important in the evaluation of brainstem injury. The circuitry of the vestibular system extends through a large part of the brainstem, and simple clinical tests of vestibular function can be performed to determine brainstem involvement, even on comatose patients.

Where is the vestibular system?

Based on Anatomy of the vestibular system by S, Chang R the vestibular system is comprised of several structures and tracts. The main components of the system are in the inner ear in a system of vestibular labyrinth. The vestibular labyrinth is made up of the semicircular canals and the otolith organs, and contains receptors for vestibular sensations. These receptors send vestibular information via the vestibulocochlear nerve to the cerebellum and to nuclei in the brainstem called the vestibular nuclei. The vestibular nuclei then pass the information on to a variety of targets, ranging from the muscles of the eye to the cerebral cortex.

What is vestibular balance disorder?

Dizziness and vertigo are symptoms of a vestibular balance disorder. Balance disorders can strike at any age, but are most common as you get older.

Your ear is a complex system of bone and cartilage. Within it is a network of canals. These are semicircular canals. The canals contain with fluid. The position of the fluid changes with movement. A sensor in the ear then sends the information to your brain to contribute to your sense of balance. These and other delicate pieces make up the vestibular system.

Certain things can affect the signals from any of the parts of the vestibular system causing symptoms.

What causes vestibular balance disorders?

Common causes of vestibular balance disorders include:

• Medicines
• Infections
• Inner ear poor circulation
• Calcium debris in your semicircular canals
• Traumatic brain injury

Source

Vestibular Disorders

Based on UK MENIERE’S SOCIETY here is a list of main disorders and quick explanation:

• Bilateral Vestibulopathy: is the reduction or absence of balance (vestibular) function in both ears.
• BPPV: dizziness occurs in short bursts.
• Cochlear Hydrops: symptoms are hearing loss, tinnitus and aural fullness, without dizziness.
• Endolymphatic hydrops: symptoms include dizziness, tinnitus, hearing loss and aural fullness.
• Labyrinthitis: makes people feel dizzy with loss of hearing.
• Mal de debarquement (MdDS): it is a symptom of the illusion of movement after travel which results in the sensation of bobbing or swaying.
• Ménière’s disease: symptoms include acute attacks of vertigo, tinnitus, increasing deafness and the feeling of pressure in the ear.
• Otoxicity: it is damage to the inner ear caused by drugs/chemicals.
• Perilymph fistula symptoms include dizziness, vertigo, imbalance, nausea, vomiting and hearing loss.
• Persistent Postural-Perceptual Dizziness (PPPD): the symptoms of PPPD are dizziness, unsteadiness and non-spinning vertigo for most days over a three month period.
• Secondary endolymphatic hydrops: symptoms include dizziness, tinnitus, hearing loss and aural fullness.
• Superior semicircular canal dehiscence syndrome (SSCD): results from an opening (dehiscence) in the bone overlying the superior (uppermost) semicircular canal within the inner ear.
• Vestibular migraine: mainly presents with dizziness symptoms. The duration of attacks are very variable, from seconds in some patients to days in others, but usually last minutes to hours.