The nerves of the brain and the spinal cord are protected by three surrounding membranes: the dura mater, arachnoid mater, and pia mater. Arachnoiditis is a pain disorder that develops when the arachnoid becomes inflamed. It is characterized by severe stinging, burning pain, and neurological problems.
Symptoms of Arachnoiditis
Symptoms of arachnoiditis can vary, but the most common is pain in the lower back or legs that is often described as burning or stinging pain. Others include:
- Weakness, numbness or tingling in the legs
- Pins and needles sensation (paresthesia)
- Joint pain
- Ringing in the ears (tinnitus)
- Bladder problems
As the disease progresses, symptoms may become more severe or even permanent. Many people with arachnoiditis are unable to work and suffer significant disability because they are in constant pain.
Causes of Arachnoiditis
Inflammation of the arachnoid can be triggered by a number of different irritants, including:
- Spinal cord injury: In most cases, it is related to complications from spinal surgery or procedure such as epidural injection and spinal tap.
- Infection: Viruses or bacteria such as bacterial meningitis of the spine can trigger the inflammation.
- Spinal nerve compression: Chronic degenerative disc disease or advanced spinal stenosis (narrowing of spinal column) can lead to compression of the spinal nerves, triggering inflammation of the arachnoid.
Diagnosing arachnoiditis can be difficult, but tests such as the CAT scan (computerized axial tomography) or MRI (magnetic resonance imaging) have helped with diagnosis. A test called an electromyogram (EMG) can assess the severity of the ongoing damage to affected nerve roots by using electrical impulses to check nerve function.
Note: Myelograms with the radiographic contrast currently in use, combined with CAT scanning, are not considered to be responsible for causing arachnoiditis or causing it to worsen.
There is no cure for arachnoiditis. Treatment options for arachnoiditis are similar to those for other chronic pain conditions. Most treatments focus on relieving pain and improving symptoms that impair daily activities. Often, health care professionals recommend a program of pain management, physiotherapy, exercise, and psychotherapy. Surgery for arachnoiditis is controversial, because outcomes can be poor and provide only short-term relief. Clinical trials of steroid injections and electrical stimulation are needed to determine whether those treatments are effective.