|Classification and external resources|
Myelogram showing arachnoiditis in the lumbar spine
Arachnoiditis is a neuropathic disease caused by inflammation of the arachnoid, one of the membranes that surround and protect the nerves of the central nervous system, including the brain and spinal cord. The arachnoid can become severely inflamed because of adverse reactions to chemicals, infection from bacteria or viruses, as the result of direct injury to the spine, chronic compression of spinal nerves, or complications from spinal surgery or other invasive spinal procedures. Inflammation can sometimes lead to the formation of scar tissue and adhesion that can make the spinal nerves "stick" together. This can be extremely painful, especially in last stage adhesive arachnoiditis—though clinical findings may not match pain levels. In other words, it may look mild on an MRI scan but the patient may experience great pain. A variety of etiologies exist with Arachnoiditis, including infectious, inflammatory, and neoplastic processes. Infectious etiologies include bacterial, viral, fungal, and parasitic agents. Noninfectious inflammatory processes include surgery, intrathecal hemorrhage, and the administration of intrathecal (inside the dural canal) agents such as myelographic contrast media, anesthetics (e.g. chloroprocaine), and steroids (e.g. Depo-Medrol, Kenalog). Lately iatrogenic arachnoiditis has been attributed to misplaced Epidural Steroid Injection therapy when accidentally administered intrathecally. The preservatives and suspension agents found in all steroid injectates, which aren't indicated nor approved for epidural administration by the U.S. Food & Drug Administration due to reports of severe adverse events including arachnoiditis, paralysis and death, have now been directly linked to the onset of the disease following the initial stage of chemical meningitis due to intrathecal contamination.
Arachnoid inflammation can lead to many painful and debilitating symptoms. Chronic pain is common, including neuralgia. Numbness and tingling of the extremities is frequent in patients due to spinal cord involvement. Bowel, bladder, and sexual functioning can be affected if the lower part of the spinal cord is affected. While arachnoiditis has no consistent pattern of symptoms, it frequently affects the nerves that supply the legs and lower back. Many sufferers find themselves unable to sit for long (or even short) periods of time, often due to severe pain as well as efferent neurological symptoms, such as difficulties controlling limbs. This is particularly problematic for patients who have trouble standing or walking for long periods, as wheelchairs don't help them. Some sufferers benefit from relatively new inventions, such as the Segway or the less expensive Stand'n'Ride alternative. Standing wheelchairs are also available, although often expensive and limited compared to these alternatives. However, standing endurance and vibration tolerance should be considered before selecting a motorized assistance device.
It is critical that patients realize that arachnoiditis symptoms vary greatly, and not all sufferers experience all symptoms. Consequently—while typically significantly life-altering—the outcome, especially with physical therapy, appropriate psychotherapy, and medication, may be better than many patients fear when they first hear the diagnosis.
Arachnoiditis is a chronic disorder, with no known cure. Pain management techniques may provide some relief to patients. Prognosis may be hard to determine because of the lack of correlation between the beginning of the disease and the start of symptoms. For many, arachnoiditis is a disabling disease that causes chronic pain and neurological deficits. It may also lead to other spinal cord conditions, such as syringomyelia.
Arachnoiditis is difficult to treat. Treatment is limited to alleviation of pain and other symptoms. Surgical intervention generally has a poor outcome, and only provides temporary relief. Steroid injections, administered either intrathecally or epidurally have been linked as a cause of the disease, therefore they are generally discouraged as a treatment and may even worsen the condition. Doctors have different views about this disease so seeking a second opinion may be wise.
Note that many doctors are unfamiliar with arachnoiditis and, mistaking it for a common disc or nerve impingement problem, order treatments that worsen the condition. Patients may be wise to see a physician with specific experience in this area, though many doctors consider themselves a specialist while aware of the disastrous outcomes even routine procedures can cause. Patient education is important.
- Arachnoiditis; Familial spinal arachnoiditis (subtype); Spinal tuberculous arachnoiditis (subtype) at NIH's Office of Rare Diseases
- Online 'Mendelian Inheritance in Man' (OMIM) Spinal arachnoiditis -182950
- Duke RJ, Hashimoto SA (April 1974). "Familial spinal arachnoiditis. A new entity". Arch. Neurol. 30 (4): 300–3. PMID 4816834.
- Arachnoiditis Information Page at NINDS
- PDR US-FDA 2010 DataSheet | Depo-Medrol | Pfizer
- DA Nelson, WM Landau | Intraspinal Steroids: History, Efficacy, Accidentality, and Controversy with review of United States Food & Drug Administration Reports | Neurosurgery/Psychiatry Review | 2001
- Moreira, Navarro et.al | Clinical & Histological Effects of the Intrathecal Administration of MPA (Depo-Medrol) in Dogs-Animal Trial | 2010 Pain Physician