Neurofibromatosis最新文献

Gliomas of the pregeniculate anterior visual pathways comprise about 5% of all intracranial tumors that occur in the first decade of life. Gliomas are the most common primary optic nerve tumor. Diagnosing a glioma of the anterior visual pathways is much easier since the advent of computerized tomography (CT) and magnetic resonance imaging (MRI); the continuing problem is appropriate management. Improved guidelines for management are suggested based on a review of the literature and the authors' experience. These guidelines include both the need to characterize accurately the location of the tumor and its clinical and radiologic progression, and the imperative to employ active intervention only when there is a specific therapeutic goal that can be used for measuring the success of the treatment.

Neurofibromas and schwannomas of major nerve trunks may present with a variety of symptoms and other clinical concerns. These include: (1) the question of malignancy, (2) pain and paresthesias, (3) cosmesis, and (4) symptoms and impending problems related to compression of adjacent structures. For these reasons, patients with neurofibromas and schwannomas may have valid reasons for surgery. Precise delineation of the anatomical relationships of the lesions and their location within peripheral nerve trunks is essential for decision making regarding when and how they should be excised; judgement regarding risks vs. benefits must be made carefully. Microsurgical dissection can be utilized to remove some nerve trunk lesions with preservation of most or all motor and sensory functions. An important goal in resecting benign lesions is to avoid sacrificing major motor and sensory functions. Three cases are presented to illustrate these concepts: 2 cases with significant motor loss following partial resection of large neurofibromas involving peripheral nerve trunks and 1 case with a large femoral nerve neurofibroma excised from the nerve trunk with microsurgical dissection, leading to relief of symptoms and complete preservation of motor function.

As subspecialty neurofibromatosis clinics and centers begin to appear in many parts of the United States and elsewhere in the world, it would be worthwhile for some of the earlier clinics to share their experiences in order to facilitate the more efficient establishment of similar clinics in as many locations as possible. In this report, emphasis is placed on the multidisciplinary nature of such a clinic, as well as on the primary roles of geneticists, neurologists, orthopedists, ophthalmologists, pediatricians, nurses and other consultants.

Beta-adrenergic receptors on cultured neurofibromatosis (NF) skin and tumor fibroblasts were characterized by a radioligand binding assay using (-)-125I-iodocyanopindolol (ICYP), a potent beta-antagonist. NF tumor fibroblasts had a very low density of beta-adrenergic receptors (0-450 binding sites/cell) when compared to fibroblasts obtained from a healthy skin area of NF patients or from healthy controls (average 1,800 binding sites/cell). The apparently low binding of ICYP to the NF tumor fibroblasts can be an expression of an alteration in the structure or function of the plasma membrane.

In a 15-year-old girl suffering from congenital constipation, megacolon combined with a 'Ranken neuroma' of the rectum and a short aganglionic segment of distal colon was observed. The specific vascular alterations in the region of the Ranken neuroma (which has previously been described in cases of von Recklinghausen neurofibromatosis) were studied, with an emphasis on immunohistochemical methods. The results suggest that the pericytes are the cells primarily involved in the distinctive alterations of the blood vessels. Respecting the similarities of the location and vascular alterations in the neurocristopathies, von Recklinghausen neurofibromatosis and Hirschsprung's disease, to those seen in vascular fibromuscular hyperplasia, the possible pathogenetic relationships of these kinds of vascular malformations are considered.

We report on a 63-year-old man with von Recklinghausen neurofibromatosis who developed a carcinoid tumor in the periampullary region and multiple small-sized leiomyomas in the duodenal wall. A high prevalence of gastrointestinal carcinoids has previously been recognized in patients with von Recklinghausen neurofibromatosis, the commonest site of origin being the duodenum or the periampullary region. The association of both conditions seems to be more than casual. Abnormalities in the development of the complex of von Campenhout or high circulating levels of nerve growth factor have been the mechanisms postulated to account for this association.

A group of 32 children with von Recklinghausen's neurofibromatosis (VRNF) and school learning problems were compared to a matched sample of learning-disordered (LD) students without known genetic or medical disorders. VRNF children were found to differ from LD children on the frequency of WISC-R verbal-performance IQ discrepancies, on Kaufman's perceptual organization factor, and on specific measures of visual-perceptual functioning. Measures of visual perception were found to be the best predictors of group membership and accurately classified 96% of the LD group and 63% of the VRNF group. VRNF subjects also differed from LD subjects on reading achievement and error patterns on the Continuous Performance Test. It is suggested that the learning problems associated with VRNF might represent a form (or forms) of LD distinct from the category of learning deficits usually associated with 'learning disabilities'.

Parents of children with von Recklinghausen neurofibromatosis often have many questions about the present status and future course of the disease, as well as about the origin of the disorder and attendant recurrence risks. The present article is intended to address many of these questions and to provide explanations in relatively nontechnical language.