Vestibular Nerve Inflammation
The vestibular nerve, known medically as the vestibulocochlear nerve (English: Vestibulocochlear nerve) or the eighth cranial nerve, is one of twelve cranial nerves that emerge from or terminate at the skull. It is a sensory nerve responsible for transmitting sensations of sound and balance through specialized receptors located in the membranous labyrinth found within the temporal bone. The labyrinth consists of two crucial components: the cochlea, which is connected to three tiny bones that convert sound waves into fluid motion, causing the hair cells to activate the vestibulocochlear nerve, and the vestibular system, which senses changes in the head’s position relative to gravity.
Vestibular nerve inflammation is clinically referred to as vestibular neuritis, a disorder that impacts the inner ear nerve, leading to its swelling. This condition disrupts the brain’s ability to accurately interpret sensory information conveyed by this nerve. It is also worth noting a related medical term, labyrinthitis. The distinction between vestibular neuritis and labyrinthitis lies in the fact that vestibular neuritis inflates one branch of the vestibulocochlear nerve—the vestibular component responsible for balance. In contrast, labyrinthitis results in swelling of both the vestibular and cochlear branches, affecting both balance and hearing.
Symptoms of Vestibular Nerve Inflammation
Vestibular nerve inflammation typically manifests as a single episode of severe vertigo lasting from 7 to 10 days; however, many individuals experience additional episodes of mild vertigo for several weeks afterwards. It is noteworthy that the initial episode is usually the most intense. Vertigo is defined as the sensation of oneself or the surrounding environment spinning.
Viral infections can be categorized into acute and chronic stages. The acute phase is characterized by the sudden onset of symptoms, with severe dizziness occurring during routine daily activities; in some cases, symptoms may present upon waking in the morning. Recovery from symptoms generally takes about three weeks. In some instances, viral infections may cause permanent damage to the nerve, leading to a chronic phase of the illness. Patients suffering from chronic vestibular nerve inflammation often find it challenging to articulate their symptoms. They may experience discomfort without a clear cause, even when their health appears satisfactory to others. Activities such as shopping, using a computer, socializing, or even closing their eyes while standing in a shower can feel burdensome due to a sense of fatigue or discomfort. Additionally, some patients report difficulty concentrating or maintaining focus, impacting their work performance. The symptoms of vestibular nerve inflammation can be summarized as follows:
- Symptoms of vestibular nerve inflammation: Symptoms can range from mild to severe, encompassing everything from subtle dizziness to intense spinning sensations. These may also include:
- Nausea and vomiting.
- Instability or loss of balance.
- Difficulties with vision and reduced concentration.
- Impairment in standing or walking in severe cases of infection.
- Symptoms of viral labyrinthitis: Viral labyrinthitis shares the same symptoms mentioned previously, accompanied by tinnitus characterized by ringing or noise in the ear, as well as occasional hearing loss.
Types of Vestibular Nerve Inflammation
It is important to note that most cases of vestibular nerve inflammation occur following a viral infection of the upper respiratory tract. Additionally, bacterial vestibular nerve inflammation may arise from untreated middle ear infections, with most instances affecting only one ear. We will elaborate on both types of inflammation affecting the vestibular nerve as follows:
- Bacterial vestibular nerve inflammation: Bacteria causing serous labyrinthitis (English: Serous labyrinthitis), affecting either the middle ear or the surrounding bone, produce a range of toxic substances that enter the inner ear through the oval or round windows, resulting in irritation of the cochlea or the vestibular system, or both. Bacterial labyrinthitis is often a consequence of untreated chronic middle ear infections and is typically characterized by mild symptoms. The second type of bacterial vestibular nerve inflammation is purulent labyrinthitis (English: suppurative labyrinthitis), which is less common than serous labyrinthitis and arises from infections of the middle ear or cerebrospinal fluid due to bacterial meningitis. In these cases, bacteria can reach the inner ear through the cochlear duct, the internal auditory canal, or through a fistula, which is an abnormal opening in the horizontal semicircular canal.
- Viral vestibular nerve inflammation: Viral infections of the inner ear are more common than bacterial infections. Viruses responsible for vestibular nerve inflammation include herpes viruses, influenza, measles, rubella, mumps, polio, hepatitis, and Epstein-Barr virus. A distinctive feature of viral infections is the potential for the virus to remain dormant within the nerve for a period, with the possibility of reactivation occurring at an unpredictable time.
Treatment for Vestibular Nerve Inflammation
Treatment for vestibular nerve inflammation resulting from infection typically involves antibiotics or antiviral medications. It is essential to note that there is no specific treatment for vestibular neuritis itself; however, certain therapies may alleviate symptoms during recovery. Medications used to manage dizziness and nausea include diphenhydramine, meclizine, lorazepam, and diazepam. Intravenous fluids may be administered if vomiting persists for an extended period, leading to dehydration.
Video: What Are the Symptoms of Ear Nerve Inflammation?
This infection often follows a common cold. What are the symptoms of ear nerve inflammation?