Access to the PPM Journal and newsletters is FREE for clinicians.
10 Articles in Volume 15, Issue #9
Differentiating Insomnia and Depression in Chronic Pain Therapy
Improving the Sex Lives of Patients With Chronic Pain
Incorporating Concierge Medicine into Pain Management
Interdisciplinary Rehabilitation: Information for Pain Practitioners
Latest Advances in the Diagnosis and Treatment of Polymyalgia Rheumatica
Letters to the Editors: Arachnoiditis, Pituitary Adenoma
Opioid Withdrawal: A New Look at Medication Options
Oral Opioids: Not for Everybody
Oxycodone Metabolism
Sexual Therapy for Patients with Chronic Pain

Letters to the Editors: Arachnoiditis, Pituitary Adenoma

November 2015

Arachnoiditis is Not A Rare Disease

While I am aware that there are many causes for arachnoiditis, a reference to arachnoiditis as a rare disease is misleading.1

The <1% incidence often cited is from a study of the first x-ray dye ever manufactured—iodized oil (Lipiodol), which was found to cause arachnoiditis. Lipiodol was replaced by the oil-based dye Pantopaque, which was promoted to be “safe.” The fact is that there were no requirements for end-users to
report any adverse reaction to the FDA. We now know that Pantopaque dye is a major cause of arachnoiditis worldwide.

Derek Morrison, BCW, Behavioural Scientist (Community Welfare)

Dear Derek,

While your conclusion that arachnoiditis is no longer “rare” is one I now support, your information needs some clarification. When magnetic resonance imaging entered clinical practice in the late 1980’s, the use of Pantopague dye coincidentally disappeared. Although there may be residual cases involving the dye, any data concerning the use of this toxic dye is simply out-dated.

PPM’s article on arachnoiditis was published a year ago, and we used the best data we could find and we remarked that the incidence was up 400% in the past decade.1 In the past year, we have received so many anecdotal reports about new cases of arachnoiditis that we no longer consider it "rare".

First, the term “arachnoiditis” is applied to inflammation of either the arachnoid layer of the dura or thecal sac, which surrounds the spinal cord or the nerve roots in the cauda equina below T12-L1. Like any other inflammatory condition, it can be acute, mild, and resolve—or it can be severe and progressive. These severe cases include patients who clearly show clumped nerve roots that are attached to the arachnoid lining. This condition is usually referred to as “adhesive” arachnoiditis.

Now that we know microglial activation causes neuroinflammation, it certainly appears proper to refer to these patients as having a spinal cord or cauda equina inflammatory disorder, regardless of whether the nerve roots are actually adhered to the arachnoid lining.

Cauda equina inflammatory disorder, including those that show adhesion to the arachnoid, can no longer be called “rare” or “uncommon”. In fact, cauda equina inflammation may actually be a major underlying cause of severe, chronic back pain and be epidemic, in nature.

In the past, arachnoiditis has been thought to be a “hopeless, untreatable” condition. We now have emerging, therapeutic measures to deal with neuroinflammation whether it be in the brain or spinal cord, and I encourage all pain practitioners to make a New Year’s Resolution to begin to better understand and treat it.

—Forest Tennant, MD, DrPH


I have a patient that has recently been diagnosed with arachnoiditis (via magnetic resonance imaging [MRI]). My practice is in a rural location, so pain management options are very limited—the closest legitimate clinic is 2 hours away by car.

I have sent my patient to a pain management clinic, but they have insisted that my patient undergo epidural steroid injections. I am not an expert on this subject, but I have read that steroid injections will have limited, if any, benefit.

I am looking for any guidance on pain medications, particularly opioid medications. My patient is currently on a fentanyl patch and short-acting oxycodone.

Lynn Hartman, DO, UPHS-Doctors Park Family Physicians, Escanaba, Michigan

Dr. Hartman,

As noted in the previous letter, you are encountering a condition that is dramatically increasing in incidence and prevalence. Unfortunately, I believe every clinician will now have to become familiar with this condition.1

The pain and disability of adhesive arachnoiditis is profound. Your patient is on fentanyl and oxycodone, which is most appropriate. A short-acting fentanyl preparation (buccal film, lozenge, or nasal spray) or even an injectable opioid may be required for the severe pain flares of arachnoiditis.

Epidural injections and any procedure that brings a potential irritant or contaminant close to the inflamed arachnoid layer or inflamed nerve roots is strictly contraindicated except in life-threatening situations. I’ve encountered many arachnoiditis patient who worsened following epidural injections, spinal taps, facet injections, or surgery. Once the arachnoid layer and/or the nerve roots in the cauda equina becomes inflamed, the inflammation may spread to the dura and even to the epidural space.

There are 2 major pain treatment goals: provide enough pain relief to function and stop the progression of neuroinflammation.

Unless controlled, the neuroinflammation progressively leads to a host of predictable complications that may include:

  • bladder and bowel dysfunction
  • gastroparesis
  • malabsorption
  • vulvodynia
  • sexual impairment
  • burning feet
  • blurred vision
  • headache
  • leg jerks or tremors
  • episodes of heat and sweating
  • inability to stand very long.

Arachnoiditis patients often can be observed sitting in your office on pillows or even laying on the floor.

In an initial attempt to stop the progression of nerve root inflammation, I start a 5-day course of methylpredinisolone. I prefer the Depo-Medrol Dose Pak (alternative corticosteroids are acceptable) for convenience. After this course, I give a 5-day course of oral ketorolac (Toradol) 10 mg three times a day.

Once the course of corticosteroids and ketorolac are finished, I develop an ongoing regimen of low-dose corticosteroid maintenance and periodic courses of ketorolac. I have found that the old anti-inflammatory agent, choline-magnesium-trisalicylate to sometimes be helpful. The standard NSAID’S haven’t been of much help.

The best analogy I can give is that treating arachnoiditis is like dealing with rheumatoid arthritis. We can’t cure it, but we can stop the destructive progression of inflammation, relieve pain, and give the patient an improved quality of life. Unfortunately, the inflammation in the central nervous system doesn’t respond well, if at all, to the usual anti-inflammatory, immunologic agents that are effective in the periphery. The control of neuroinflammation is very difficult, and we are in the early stages of developing effective treatments for it.2

The basic treatment of arachnoiditis is aggressive anti-neuroinflammatory measures and potent analgesia. Reasonable pain relief, stretching exercises, and walking are a must. Once these are in place there are a number of neuropathic agents, microglial modulators, topical agents, and neurohormones that I am using and are helpful in selected cases, but space here doesn’t allow description of these alternatives.

—Forest Tennant, MD, DrPH

Pituitary Adenoma

Do you think it would be possible for some of the hormone mediators of pain (cortisol, etc.) to give a false- normal serum result in the presence of centralized pain and a pituitary microadenoma? Have you ever heard of a pituitary-adrenal disorder becoming diagnosable after pain was better managed? One more question: Is there any evidence of prolactin serum being a chronic pain mediator? 

Tessa Watts, utahneurotherapy.com

Dear Tessa,

Thank you for your most interesting letter.You’ve clearly been studying and you have some valid points. Here’s what I know about pituitary adenoma and pain. Yes, I believe that constant, centralized pain could give a normal cortisol serum level, even if the adenoma is secreting excess amounts of ACTH. 

Why? I recently analyzed serum cortisol levels in my centralized, intractable pain patients. Almost all of the patients had low cortisol levels compared to normal controls. I’m of the growing opinion that low doses of a corticosteroid should probably be part of the routine treatment in most severe, centralized pain cases. For example, a low daily or every other day dose of methylprednisolone is being given to all our arachnoiditis patients. 

I have 3 patients who were diagnosed by endocrinologists as having hypopituitarism and placed on total replacement therapy. After a few months of good pain management, their pituitary clearly regained function. We have now looked at prolactin levels in some of our severe pain patients. It is elevated in about 20%. This finding has, I believe, been found by others. I am unsure of the significance.  Please share your thoughts.  At this point there are no bad or “far out” theories!!

—Forest Tennant, MD, DrPH

Last updated on: November 10, 2015
Continue Reading:
Oral Opioids: Not for Everybody
close X