fibroblasts. Neurofibromas may arise sporadically, or in association with NF-1. A neurofibroma may arise at any point along a peripheral nerve. A number of drugs have been studied to treat this condition. Neurofibroma conditions are progressive and include: Plexiform neurofibroma: Often congenital. Lesions are composed of sheets of neurofibromatous tissue that may infiltrate and encase major nerves, blood vessels, and other vital structures. These lesions are difficult and sometimes impossible to routinely resect without causing any significant damage to surrounding nerves and tissue. However, early intervention may be beneficial: a 2004 study in Germany concluded "Early surgical intervention of small superficial PNFs is uncomplicated, without burden for even the youngsters and enables total resection of the tumors. It may be considered as a preventive strategy for later disfigurement and functional deficits." Solitary neurofibroma, affecting 8–12% of patients with NF-1. This occurs in a deep nerve trunk. Diagnosis by cross-sectional imaging (e.g., computed tomography or magnetic resonance) as a fusiform enlargement of a nerve. Schwannomas, peripheral nerve-sheath tumors which are seen with increased frequency in NF-1. The major distinction between a schwannoma and a solitary neurofibroma is that a schwannoma can be resected while sparing the underlying nerve, whereas resection of a neurofibroma requires the sacrifice of the underlying nerve. Nerve root neurofibroma. Bones, especially the ribs, can develop chronic erosions (pits) from the constant pressure of adjacent neurofibroma or Schwannoma. Similarly, the neural foramen of the spine can be widened due to the presence of a nerve root neurofibroma or schwannoma. Surgery may be needed when NF-1 related tumors compress organs or other structures. Nerve sheath tumor Chronic pain, numbness, and/or paralysis due to peripheral nerve sheath tumor. Other complications Renal artery anomalies or pheochromocytoma and associated chronic hypertension Schwannoma Plexiform fibromas Optic nerve glioma Epilepsy Central nervous system disease Epilepsy Occurrence. Epileptic seizures have been reported in up to 7% of patients. Diagnosis. Electroencephalograph, magnetic resonance imaging, computed tomographic scan, single-photon emission CT and positron emission tomographic scan. Etiology. Due to cerebral tumors, cortical malformation, mesial temporal sclerosis. Therapy. Drug therapy (57% amenable) where not resistant (29%). Glial tumors Intracranially, NF-1 patients have a predisposition to develop glial tumors of the central nervous system, primarily: Optic nerve gliomas and associated blindness. Astrocytoma Focally degenerative myelin Another CNS manifestation of NF-1 is the so-called "unidentified bright object" or UBO, which is a lesion which has increased signal on a T2