What is neuritis?
It is a general term for inflammation of peripheral nerves (nerves outside of the central nervous system). The symptoms will vary according to the nerves that are affected but can include weakness, numbness, pain, pins and needles, disappearance of reflexes, muscle wasting or the senses may be affected (e.g. eyesight, balance, hearing). These symptoms may be temporary or permanent.
What are the different types of neuritis?
There are many different forms some of which are listed and described below. In each form different nerves are inflamed resulting in different symptoms.
|Generalised neuritis||-Leads to pain, weakness and/or paralysis of the limbs
-It’s caused by poisoning, alcoholism, vitamin deficiency diseases and bacterial and viral infections
-It generally resolves once the cause is removed
|Bell’s palsy||-Inflammation of the facial nerve
-Leads to paralysis or paresis (weakness) of facial muscles usually on one side of the face
-Thought to be caused by an autoimmune problem or infection
-Often resolves after a few months
|Sciatica||-Inflammation or compression of the sciatic nerve
-The sciatic nerve connects the spinal cord to the leg
-Pain, weakness or paralysis may be experienced in the leg or buttock region
-Cases generally resolve without intervention after a few days
|Optic neuritis||-Inflammation of the optic nerve that connects the eyes to the brain
-Results in blurred or dimmed vision
-Caused by viral infections or multiple sclerosis
-Generally resolves once the infection clears
|Vestibular neuritis||-Condition of the inner ear that causes a sudden onset of vertigo, nausea and vomiting
-Inflammation of the vestibular nerve that supplies the brain with information about balance
-Caused by a viral or bacterial infection
-Generally resolves after 1-2 weeks
|Auditory neuropathy||-Not technically a form of neuritis because an auditory neuropathy is not necessarily caused by inflammation of the auditory nerve
-The cause is not well understood but may be due to damage of the auditory nerve, cochlear hair cells or brainstem auditory pathways
-Symptoms include varying forms of hearing loss, e.g. fluctuating hearing loss, mild-severe hearing loss, difficulties with speech perception and fading of sounds
|Brachial neuritis||-Inflammation of the brachial plexus
-The brachial plexus contains nerves that connect the central nervous system to the arm, shoulder and chest
-Results in pain, numbness and/or weakness of the shoulder, chest and arm
-May be due to infection, trauma or a systemic illness
|Lumbar neuritis||-Inflammation of the lumbar nerves
-Causes lower back pain, weakness and/or numbness
What causes neuritis?
There are many different causes. These include but are not limited to: viral or bacterial infection, trauma, diabetes, vascular diseases, surgery, autoimmune diseases, alcoholism, poisoning (e.g. lead poisoning) and poor nutrition.
Can neuritis affect the ear and hearing?
It can affect the ear and hearing if the vestibulocochlear nerve is inflamed. This nerve splits into the vestibular nerve and the auditory nerve. The vestibular nerve connects the central nervous system to the vestibular system which resides in the inner ear. The vestibular system is responsible for sending information to the brain about balance. When the vestibular nerve is inflamed this is known as vestibular neuritis. Vestibular neuritis causes vertigo, nausea and vomiting.
In cases where the auditory nerve is inflamed hearing loss will result. This is known as an auditory neuropathy. An auditory neuropathy results when the transmission of auditory information from the auditory nerve to the brain is disturbed. Auditory neuropathies are not well understood and may be caused by damage to the auditory nerve, cochlear hair cells or brainstem auditory pathways and therefore are not necessarily due to inflammation.
How is it diagnosed?
This will vary according to the type of neuritis, however the following assessments are generally required for a diagnosis. Collection of a detailed medical history, a blood test and a physical examination. Medical imaging tests, biopsies, hearing assessments and other tests may also be required.
How is it treated?
This will depend on the presenting signs and symptoms along with the type of neuritis and the cause. Therefore, it’s important that you see your doctor so that the best treatment can be selected for you. Medications, physiotherapy, lifestyle changes and surgery are the most frequently used treatments. Medications include pain relievers, anti inflammatory drugs, antibiotics, antiviral drugs and motion sickness drugs to manage vertigo.
Physiotherapy may be recommended to regain muscle strength and reduce pain. Lifestyle changes are recommended for those whose symptoms are due to poor nutrition, diabetes or vascular conditions. While surgery may be recommended in severe cases.
How can hearing loss be managed?
If hearing loss is permanent hearing aids or cochlear implants may be beneficial. An audiologist will assess your hearing and help you select the best option to improve your hearing.
Hearing aids are suitable for those with a permanent mild-severe hearing loss. There are a range of hearing aids available and your audiologist will help you select the most suitable device for you. Hearing aids function by amplifying sound waves. All hearing aids have four essential components: a microphone, an amplifier, a receiver and a battery source. The microphone detects sound which is then amplified and delivered to the ear by the receiver.
Cochlear implants are suitable for those with a severe-profound permanent hearing loss.
Cochlear implants (also known as bionic ears) are electrical devices surgically inserted into the inner ear. Users wear a small microphone behind their ear that converts sound waves into an electrical signal. The electrical signal is then transmitted to the implant within the ear which stimulates the auditory nerve allowing the user to hear. Cochlear implants may be suitable for those with bilateral profound hearing loss (profound hearing loss in both ears).