Author
Richard T. Ramsden
Other affiliations: University Hospitals Bristol NHS Foundation Trust, Central Manchester University Hospitals NHS Foundation Trust
Bio: Richard T. Ramsden is an academic researcher from Manchester Royal Infirmary. The author has contributed to research in topics: Cochlear implant & Neurofibromatosis. The author has an hindex of 36, co-authored 162 publications receiving 5257 citations. Previous affiliations of Richard T. Ramsden include University Hospitals Bristol NHS Foundation Trust & Central Manchester University Hospitals NHS Foundation Trust.
Papers published on a yearly basis
Papers
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TL;DR: In this article, a clinical and genetic study of type 2 neurofibromatosis (NF2) has been carried out in the United Kingdom and the results show that there are two types of NF2, one with later onset and bilateral vestibular schwannomas as the only usual feature and the other with earlier onset and multiple other tumours.
Abstract: A clinical and genetic study of type 2 neurofibromatosis (NF2) has been carried out in the United Kingdom. Virtually complete ascertainment of cases in the north-west of England was achieved and suggests a population incidence of 1 in 33,000 to 40,000. In the UK as a whole, 150 cases have been identified and been used to study the clinical and genetic features of NF2. The autosomal dominant inheritance of NF2 was confirmed, 49% of cases were assessed as representing new mutations, and the mutation rate was estimated to be 6.5 x 10(-6). Evidence to support a maternal gene effect was found in that age at onset was 18.17 years in 36 maternally inherited cases and 24.5 in 20 paternally inherited cases (p = 0.027). The preponderance of maternally inherited cases was also significant (p = 0.03). Data are presented which suggest that there are two types of NF2, one with later onset and bilateral vestibular schwannomas as the only usual feature, and the other with earlier onset and multiple other tumours. A considerable number of cases did not fall easily into one or other group and other factors such as maternal effect on severity and anticipation need to be considered.
396 citations
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TL;DR: Hearing may be conserved in adults after implantation with the Nucleus Contour Advance perimodiolar electrode array and the benefits of combined electrical and acoustic stimulation are presented.
Abstract: CONCLUSIONS: Hearing may be conserved in adults after implantation with the Nucleus Contour Advance perimodiolar electrode array. The degree of hearing preservation and the maximum insertion depth of the electrode array can vary considerably despite a defined surgical protocol. Residual hearing combined with electrical stimulation in the same ear can provide additional benefits even for conventional candidates for cochlear implantation. OBJECTIVES: We present preliminary results from a prospective multicentre study investigating the conservation of residual hearing after implantation with a standard-length Nucleus Contour Advance perimodiolar electrode array and the benefits of combined electrical and acoustic stimulation. MATERIAL AND METHODS: The subjects were 12 adult candidates for cochlear implantation recruited according to national selection criteria. A "soft" surgery protocol was defined, as follows: 1-1.2-mm cochleostomy hole anterior and inferior to the round window; Nucleus Contour Advance electrode array inserted using the "Advance-off-stylet" technique; and insertion depth controlled by means of three square marker ribs left outside the cochleostomy hole. These procedures had been shown to reduce insertion forces in temporal bone preparations. Variations in surgical techniques were monitored using a questionnaire. Pure-tone thresholds were measured pre- and postoperatively. Patients who still retained thresholds <90 dB HL for frequencies up to 500 Hz were re-fitted with an in-the-ear (ITE) hearing aid. Word recognition was tested in quiet and sentence perception in noise for the cochlear implant alone and in combination with an ipsilateral hearing aid. RESULTS: Hearing threshold level data were available for 12 patients recruited from 6 of the centres. Median increases in hearing threshold levels were 23, 27 and 33 dB for the frequencies 125, 250 and 500 Hz, respectively. These median increases include the data for two patients who had total loss of residual hearing due to difficulties encountered during surgery. "Cochlear view" X-ray images indicated that the depth of insertion varied between 300 and 430 degrees, despite modest variations in the length of the electrode inserted (17-19 mm). The insertion angle had some influence on the preservation of residual hearing at frequencies of 250-500 Hz. Six of the 12 patients retained sufficient hearing for effective use of an ipsilateral ITE hearing aid (< or = 80 dB HL at 125 and 250 Hz; < or = 90 dB HL at 500 Hz). Word recognition scores in quiet were improved from 10% to 30% with the cochlear implant plus ipsilateral hearing aid in 3 patients who had at least 3 months postoperative experience. Signal:noise ratio thresholds for sentence recognition were improved by up to 3 dB. Patients reported that they experienced greatly improved sound quality and preferred to use the two devices together.
266 citations
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TL;DR: It is indicated that much more caution is warranted regarding the use of radiation treatment for benign tumours in childhood and in tumour prone conditions such as the neurofibromatoses.
Abstract: In recent years the use of radiation treatment for benign tumours has increased with the advent of stereotactic delivery and, in particular, single high dose gamma knife therapy. This has been particularly true for benign CNS (central nervous system) tumours such as vestibular schwannoma, meningioma, pituitary adenoma, and haemangioblastoma. While short term follow up in patients with isolated tumours suggests this treatment is safe, there are particular concerns regarding its use in childhood and in tumour predisposing syndromes. We have reviewed the use of radiation treatment in these contexts with particular regard to malignant transformation and new tumour induction. This review indicates that much more caution is warranted regarding the use of radiation treatment for benign tumours in childhood and in tumour prone conditions such as the neurofibromatoses.
258 citations
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TL;DR: Minimal interference, maintenance of quality of life, and conservation of function or auditory rehabilitation are the cornerstones of NF2 management, and the decision points to achieve these goals for patients with different clinical presentations are discussed.
Abstract: A consensus conference on neurofibromatosis 2 (NF2) was held in 2002 at the request of the United Kingdom (UK) Neurofibromatosis Association, with particular emphasis on vestibular schwannoma (VS) surgery. NF2 patients should be managed at specialty treatment centres, whose staff has extensive experience with the disease. All NF2 patients and their families should have access to genetic testing because presymptomatic diagnosis improves the clinical management of the disease. Some clinical manifestations of NF2, such as ocular abnormalities, can be detected in infancy; therefore, clinical screening for at-risk members of NF2 families can start at birth, with the first magnetic resonance (MRI) scan at 10-12 years of age. Minimal interference, maintenance of quality of life, and conservation of function or auditory rehabilitation are the cornerstones of NF2 management, and the decision points to achieve these goals for patients with different clinical presentations are discussed.
214 citations
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TL;DR: None of the existing sets of criteria for neurofibromatosis 2 are adequate at initial assessment for diagnosing people who present without bilateral vestibular schwannomas as having NF2, particularly people with a negative family history of NF2.
Abstract: Background: Four sets of clinical diagnostic criteria for neurofibromatosis 2 (NF2) have been developed by groups of expert clinicians, but sensitivity has never been formally assessed. The sets of criteria differ for people without bilateral vestibular schwannomas, which are pathognomonic for NF2. Objective: To empirically evaluate the four existing sets of clinical diagnostic criteria for NF2. Methods: The study was based on 163 of 403 people in the United Kingdom NF2 registry (41%) who presented without bilateral vestibular schwannomas. The authors applied the sets of criteria to each person at initial assessment and at the most recent clinical evaluation (mean ± SE length of follow-up, 13 ± 1 years). Results: In people with “definite NF2” and a negative family history of NF2, the 1987 US NIH and 1991 NIH criteria each identify 78% of people at the most recent clinical evaluation but 0% at initial assessment. The National Neurofibromatosis Foundation (NNFF) criteria and the Manchester criteria each identify higher proportions at both time points (NNFF criteria, 91% and 10%; Manchester criteria, 93% and 14%), but the proportions at initial assessment are still low. Conclusions: None of the existing sets of criteria are adequate at initial assessment for diagnosing people who present without bilateral vestibular schwannomas as having NF2, particularly people with a negative family history of NF2. The authors recommend that a single, revised set of diagnostic criteria be devised to replace all of the existing sets of criteria.
200 citations
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9,362 citations
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TL;DR: The deduced product has homology with proteins at the plasma membrane and cytoskeleton Interface, a previously unknown site of action of tumour suppressor genes in humans.
Abstract: Neurofibromatosis type 2 (NF2) is a monogenic dominantly inherited disease predisposing carriers to develop nervous system tumours. To identify the genetic defect, the region between two flanking polymorphic markers on chromosome 22 was cloned and several genes identified. One is the site of germ-line mutations in NF2 patients and of somatic mutations in NF2-related tumours. Its deduced product has homology with proteins at the plasma membrane and cytoskeleton interface, a previously unknown site of action of tumour suppressor genes in humans.
1,279 citations
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TL;DR: A candidate gene for the NF2 tumor suppressor that has suffered nonoverlapping deletions in DNA from two independent NF2 families and alterations in meningiomas from two unrelated NF2 patients is identified.
1,268 citations
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TL;DR: The diagnostic criteria for neurofibromatosis 1 and neurof fibromaatosis 2, recommendations for the care of patients and their families at diagnosis and during routine follow-up, and the role of DNA diagnostic testing in the evaluation of these disorders are determined.
Abstract: Objective. —Neurofibromatosis 1 and neurofibromatosis 2 are autosomal dominant genetic disorders in which affected individuals develop both benign and malignant tumors at an increased frequency. Since the original National Institutes of Health Consensus Development Conference in 1987, there has been significant progress toward a more complete understanding of the molecular bases for neurofibromatosis 1 and neurofibromatosis 2. Our objective was to determine the diagnostic criteria for neurofibromatosis 1 and neurofibromatosis 2, recommendations for the care of patients and their families at diagnosis and during routine follow-up, and the role of DNA diagnostic testing in the evaluation of these disorders. Data Sources. —Published reports from 1966 through 1996 obtained by MEDLINE search and studies presented at national and international meetings. Study Selection. —All studies were reviewed and analyzed by consensus from multiple authors. Data Extraction. —Peer-reviewed published data were critically evaluated by independent extraction by multiple authors. Data Synthesis. —The main results of the review were qualitative and were reviewed by neurofibromatosis clinical directors worldwide through an Internet Web site. Conclusions. —On the basis of the information presented in this review, we propose a comprehensive approach to the diagnosis and treatment of individuals with neurofibromatosis 1 and neurofibromatosis 2.
1,150 citations
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TL;DR: A histological classification of CNS Tumours is presented, highlighting the importance of knowing the carrier and removal status of canine coronavirus as a source of infection for humans.
Abstract: Introduction Histological Classification of CNS Tumours Definitions and Explanatory Notes Tumours of Neuroepithelial Tissue Astrocytic Tumours Ependymal Tumours Mixed Gliomas Choroid Plexus Tumours Neuroepithelial Tumours of Uncertain Origin Neuronal and Mixed Neuronal-Glial Tumours Pineal Parenchymal Tumours Embryonal Tumours Tumours of Cranial and Spinal Nerves Schwannoma Neurofibroma Malignant Peripheral Nerve Sheath Tumor Tumours of the Meninges Tumours of Menigothelial Cells Mesenchymal, Non-menigothelial Tumours Primary Melanocytic Lesions Lymphomas and Haemopoietic Neoplasms Germ Cell Tumours Cysts and Tumour-like Lesions Tumours of the Sellar Region Local Extensions from Regional Tumours Metastatic Tumours Unclassified Tumours Illustrations Subject Index Metat Cy Tu
853 citations