Surgery is likely to alleviate pain, but often unfavorable and often at the cost of some motor or sensory deficit. However, once again, with peripheral schwannomas, there is an excellent chance of a favorable outcome. As I mentioned before, the aqueduct of Sylvius can be very small or blocked in NF1 patients causing hydrocephalus. One of the Children's Hospital radiologists has been measuring the corpus callosa of NF1 patients on MRI scan to discover the incidence and types of abnormalities seen and correlate this with any functional abnormalities in these patients. So the radiologist may be able to clear up some of this mystery.
Radiation seems to be causing problems.
This is true for any disease being treated by radiation. Children who have leukemia and receive radiation treatment can develop secondary malignancies in adulthood. It is not very common. I could not find any actual statistics of what the increased risk for Moya Moya disease and malignant degeneration of neurofibromas is after radiation. The difficulty lies in that so few physicians have a big enough population of NF1 patients to reach statistical significance about the risk.