Symptoms for neurofibromatosis type 1 include:
• Presence of light brown sports (café-au-lait) on the skin.
• Appearance of two or more neurofibromas (pea-sized bumps) that can grow either on the nerve tissue, under the skin or on many nerve tissues.
• Manifestation of freckles under the armpits or in the groin areas.
• Appearance of tiny tan clumps of pigment in the iris of the eyes (Lisch nodules)
• Tumors along the optic nerve of the eye (optic glioma).
• Severe curvature of the spine (scoliosis)
• Enlargement or malformation of other bones in the skeletal system.
Symptoms for NF1 vary for each individual. Those that are skin-related are often present at birth, during infancy and by a child's tenth birthday. From ages 10 to 15, neurofibromas may become apparent. Symptoms such as café-au-lait spots, freckling and Lisch nodules pose minimal or no health risk to a person.
Though neurofibromas are generally a cosmetic concern for those with NF1, they can sometimes be psychologically distressing. For 15 percent of individuals with NF1, the symptoms can be severely debilitating. Neurofibromas can grow inside the body and may affect organ systems. Hormonal changes at puberty and/or even pregnancy may increase the size of neurofibromas. Nearly 50 percent of children with NF1 have speech problems, learning disabilities, seizures and hyperactivity. Less than one percent of those affected with NF1 may have malignant tumors and may require treatment.
Symptoms for neurofibromatosis type 2 include:
• Tumors along the eighth cranial nerve (schwannomas)
• Meningiomas and other brain tumors
• Ringing noises inside the ear (tinnitus), hearing loss and/or deafness
• Cataracts at a young age
• Spinal tumors
• Balance problems
• Wasting of muscles (atrophy)
Individuals with NF2 develop tumors that grow on the eighth cranial nerves and on the vestibular nerves. These tumors often cause pressure on the acoustic nerves, which result in hearing loss. Hearing loss may begin as early as an individual's teenage years. Tinnitus, dizziness, facial numbness, balance problems and chronic headaches may also surface during the teenage years. Numbness may also occur in other parts of the body, due to spinal cord tumors.
The rare form of NF, schwannomatosis, which was recently identified, does not develop on the eighth cranial nerves, and does not cause hearing loss. It causes pain primarily, and in any part of the body. Though schwannomatosis may also lead to numbness, weakness or balance problems like NF1 or NF2, the symptoms are less severe.