In news related to the UAB NF Program, I’d like to mention that that Department of Defense NF Research Program has issued a request for grant applications (RFAs) from investigators to support innovative, high-impact NF research.  Several of our faculty members have submitted proposals, and more updates will follow as the process moves forward.

Pain Related to NF1

In this month’s post, I think it would be helpful to discuss the issue of pain in the context of NF, other than headaches, which have been covered previously. Individuals with neurofibromatosis type 1, the most common form of NF, can sometimes experience pain related to the presence of neurofibromas, benign tumors that can grow on nerves throughout the body.  While neurofibromas are not typically painful, some people have pain associated with these tumors that may take a variety of forms. Cutaneous neurofibromas, which appear on the surface of the skin, can sometimes result in pain due to an event that causes pressure on the tumor, such as hair brushing.  These tumors can also become infected, which can be painful.  Subcutaneous neurofibromas, occurring under the skin, can be nodular and are usually pea-sized to marble-sized. Though not typically painful most of the time, they can be tender to the touch or pressure such as hair brushing or lying down. Subcutaneous neurofibromas on the scalp can also serve as trigger points for headaches by internally pressing on nerves and surrounding structures, causing pain.

Plexiform neurofibromas occur deep inside the body and are usually not painful unless causing pressure on internal structures. There are instances in which they can press on nerve roots, resulting in significant pain. Some individuals with NF1 develop a condition call dural ecstasia in which there is a ballooning of the membranes surrounding the spinal cord that can put pressure on surrounding nerves, resulting in pain in the lower back or legs.   This can be a very difficult condition to treat surgically, and may result in chronic pain.

Some adults with NF1 may also experience exquisite pain with pressure applied at the tips of fingers and toes due to the presence of glomus tumors that occur under the nail beds. Fortunately, this pain can be eliminated by removing these tumors surgically; however, many adults don’t associate this pain with NF and therefore don’t seek treatment. It’s important for patients and clinicians to be alert to this type of pain so that surgery can be performed if needed.

Malignant peripheral nerve sheath tumors, which occur in 10% of people with NF1, cause a nagging, unremitting pain that becomes worse over time. It’s important to recognize this type of pain so that an imaging study, such as an MRI and PET scan, can be performed to identify the tumor and recognize its malignant potential.  For this reason, people with NF should be alert to any unexplained and persistent pain.

Pain Related to NF2 and Schwannomatosis

Chronic pain can occur in individuals with neurofibromatosis type 2 due to nerve root compression by one of the two types of tumors associated with the condition, meningiomas and schwannomas.

People with schwannomatosis, the third distinct type of NF, usually experience excruciating pain, which is a hallmark of the condition. Surgical removal of schwannomas usually relieves pain, although surgery is not always feasible due to the location of the tumors. Interestingly, the pain tends to be out of proportion with the number and size of tumors. Small tumors can be surprisingly painful, which may indicate there is something inherent in the tumor that causes pain.

Pain Management and Signs to Seek Treatment

In mild instances of NF-related pain, over-the-counter medications, such as Ibuprofen, are usually indicated and can be effective. Pain due to nerve compression or dysfunction sometimes responds to the medicine gabapentin or other similar medications.  Also, pain management programs can be helpful in dealing with chronic pain for which there is not a treatment option available. These programs have extensive experience in helping patients achieve symptom relief while avoiding addictive drugs when possible.

In conclusion, it’s important for individuals with NF to understand the signs of when to seek treatment for pain, including: chronic or nagging pain that gets worse over time; neurofibromas that become noticeably larger; pain with pressure applied to the tips of fingers and toes; and localized pain, which may be an indication of nerve root compression.