A Study to Evaluate the Feasibility of a Physiologic Biomarker to Assess Pain and Other Sensory Problems Using Pupillometry in Participants With Neurofibromatosis Type 1 (NF1)

Background: Neurofibromatosis type 1 (NF1) is a genetic condition that causes tumors to grow along the nerves in the skin, brain, and other parts of the body. People with NF1 often have pain and may experience other abnormal sensations like itching, numbness, or tingling. These symptoms can affect their daily life. Researchers want to learn more about these symptoms and find better ways to measure pain in people with NF1. Objective: To learn if a device called the AlgometRx Nociometer(Registered trademark) is effective in measuring pain or other abnormal sensations in people with NF1. Eligibility: People aged 1 year and older with NF1. Design: Individuals can have up to 3 assessments completed in person. Each assessment may last up to 1.0 to 1.5 hours. Individuals will be screened. They will complete questionnaires about their health and how bad their pain is. If participants are having blood drawn for other reasons, some additional samples may be used in this study. The AlgometRx Nociometer includes an electrode that will be placed onto a finger or a toe. The electrode will send non-painful electrical signals to activate nerves in the finger or toe. At the same time, a camera will be used to record changes in the pupil of the eye. The test will be done on all 4 of the participant s limbs; however, researchers may skip 1 or more limbs for various reasons. This test takes about 10 seconds to complete with at least a one-minute rest between testing different limbs. Individuals will be asked to do a 2nd assessment with the AlgometRx Nociometer that may be done 1 hour later but no more than 72 hours after the first assessment. Participants who will be returning for another visit can opt to do a 3rd assessment that will be done at least 4 weeks but not more than 18 months after the 1st....

Sex

All

Minimum age

1 Year

Maximum age

120 Years

* INCLUSION CRITERIA:
* History of clinical or genetic diagnosis of NF1 as per the 2021 revised diagnostic criteria
* Age \>= 1 year
* At least one digit (finger or toe) without open wounds for application of the device
* Individuals must understand English or Spanish
* Individuals who are \< 18 years must have a caregiver willing to help the child engage in study procedures, assist with fitting the AlgometRx Nociometer (Registered Trademark) device, and complete the observer reported (ObsRO) measures. Note: the caregiver of a child participant \>= 5 years old must be able to understand English or Spanish, the caregiver of a child participant 1-4 years old must be able to understand English (to help complete the observational pain measure for the younger children that is only available in English)
* Ability of individual or parent/guardian to understand and the willingness to sign a written informed consent document

EXCLUSION CRITERIA

* History of eye pathology which precludes pupillometry, such as problems with pupillary reflex, blindness or inability to open at least one eye fully for evaluation
* Individuals with chronic use of medication that specifically affects their pupillary response, such as atropine-containing eye drops
* Uncontrolled intercurrent illness evaluated by medical history that would potentially increase the risk to the participant