Neuritis

There are various types of neuritis, but the common ones are:

• Optic neuritis: Optic neuritis is the inflammation of the optic nerve which can present with pain on eye movement and temporary loss of vision.
• Brachial neuritis: Brachial neuritis is inflammation of the brachial plexus that contains the nerves to the chest, shoulder, arms and hands. The pain usually affects only one side of the body with loss of muscle control in the arms and hands and sometimes paralysis.
• Vestibular neuritis: Vestibular neuritis is the inflammation of the vestibular nerve which is present in the inner ear. This nerve connects the brain to the ear. 
• Cranial neuritis: Cranial neuritis can be a sign of a life-threatening condition. It is the inflammation of the cranial nerves which are present in the brain or the brain stem. They usually affect the face and the eye of the affected side. Cranial neuritis affects the third, fourth, sixth and seventh cranial nerve.
• Lumbar neuritis: Lumbar neuritis, also known as lumbosacral neuritis, is the inflammation of nerves that emerge from the spinal canal and provide nerve supply to the lumbar region of the spine. The lumbar region is the lower back region of the body.

The symptoms of neuritis are usually restricted to the specific part of the body which is served by that inflamed nerve or group of nerves. The symptoms of the common variants of neuritis are:

• Optic neuritis symptoms: A dull ache behind the back of the eye, blurry or dim vision, colour blindness, temporary or permanent loss of vision.  
• Brachial neuritis symptoms: Severe pain in the upper arm, pain affecting only one side of the body, loss of muscle control, loss of sensation and sometimes paralysis in the affected arm or shoulder.
• Vestibular neuritis symptoms: Dizziness, vertigo, inability to concentrate, unsteadiness, unable to balance the body on standing, blurred vision, nausea and vomiting.
• Cranial neuritis symptoms: Tingling or burning sensation in the affected part, stabbing pain, muscle weakness, facial paralysis, drooping of face to the affected site, double vision, droopy eyelid, drooling and slurring of speech. 
• Lumbar neuritis symptoms: Lower back pain, pain travelling down to the leg, muscle weakness and inability to walk.

The cause of nerve inflammation can be different for the different parts of the body. The causes of the common variants of neuritis are:

• Optic neuritis causes: Though the cause of optic neuritis is not exactly known, some scientists believe that it could be an autoimmune condition - which occurs when the body’s immune system starts attacking healthy cells. They also believe that people who have had viral diseases like mumps, measles and flu are more prone to neuritis.
• Brachial neuritis causes: There is no definite reason behind brachial neuritis but it can occur due to any injury to the brachial plexus - the mesh of nerves that go to the shoulders, chest, arms and hands.
• Vestibular neuritis causes: Vestibular neuritis is majorly caused due to viral infections like measles, herpes, hepatitis, Epstein Barr virus. 
• Cranial neuritis causes: Cranial neuritis can occur due to infection (Lyme disease), increased pressure in the brain, brain swelling, trauma to the head, autoimmune disease like lupus, congenital or birth defects, aneurysms (bulge in the blood vessels that presses the nerves) and cancer.
• Lumbar neuritis causes: Lumbar neuritis can occur due to an infection, the nerve can get compressed due to a spinal tumour, a bone spur (a pointed part of a bone) or a herniation of the disk of the spinal bone (slipped disc). 

Since the cause of optic neuritis is unknown, there are no measures that can prevent optic neuritis. The preventive measures of other variants of neuritis are:

• Brachial neuritis prevention: Try to prevent injuries to your shoulder as that is where the brachial plexus is located.
• Vestibular neuritis prevention: Get properly vaccinated for viral diseases, for instance, MMR vaccine which works against measles, mumps and rubella. Maintain proper hygiene and wash your hands before eating. 
• Cranial neuritis prevention: Since you cannot directly prevent cranial neuritis, you can reduce the risk factors that can lead to a stroke. Maintain your weight, and consume less oily and salty food to maintain your blood pressure. 
• Lumbar neuritis prevention: Correct your posture while sitting and stretch after every half an hour if you’re sitting for a long time. Exercise regularly and maintain your weight to put less pressure on your spine.

Read more: Exercises to improve your posture

To diagnose neuritis, an ear, nose and throat or ENT specialist may work along with a neurologist and perform various medical tests like:

• An ophthalmoscope can be used to check the retina in the case of optic neuritis.
• CT scan and MRI scan would be used to check the affected nerve.
• Electromyography is a procedure which is used to check the nature and extent of nerve inflammation.
• Hearing tests would be done in the case of vestibular neuritis.
• The spinal tap is a test done by puncturing the lumbar region and taking out the spinal fluid. This test helps in looking for infection or inflammation in the spinal fluid.

The treatment of neuritis depends upon the underlying cause:

• Optic neuritis treatment: The treatment aims to maintain the eyesight and prevent it from worsening. Doctors may prescribe corticosteroids to the patients to prevent vision loss.
• Brachial neuritis treatment: In the less severe cases, the pain resolves on its own. But for the others, the doctor may prescribe corticosteroids for pain relief and faster recovery. Transcutaneous electrical stimulation (TENS) therapy can be used to relieve the pain as it involves the transmission of electrical signals to the affected part of the body. 
• Vestibular neuritis treatment: Anti-viral drugs like acyclovir are given to deal with the viral infection. The doctor may also prescribe medications like diazepam and lorazepam for dizziness.
• Cranial neuritis treatment: Corticosteroids and anti-viral drugs (like acyclovir) are helpful in the case of facial paralysis. Medicines are also given to reduce swelling in the brain. Some patients may require brain surgery to fix the damaged part of the nerve.
• Lumbar neuritis treatment: Non-steroidal Anti Inflammatory Drugs (NSAIDs) like aspirin are given to relieve the pain. Steroid injections are given to initiate recovery and reduce inflammation.

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