Neurofibromatosis type 2 in the elderly population: clinical and molecular features.

Neurofibromatosis type 2 (NF2) is rare genetic disorder characterized by the development of multiple benign tumors of the nervous system. The majority of people with NF2 are diagnosed in the second or third decade of life with bilateral vestibular schwannomas. Among NF2 patients followed up in our NF2 clinic, seven patients have been diagnosed with NF2 after the age of 70 years. Bilateral vestibular schwannomas were present in 4/7 patients. No NF2 mutation was identified by blood screening, suggesting a high prevalence of NF2 somatic mosaicism. During a mean follow-up of 96 months, 8/11 vestibular schwannomas demonstrated no tumor growth, and only one patient required treatment. Other tumors, including meningiomas and other schwannomas, remained stable. One patient required shunting for secondary normal-pressure hydrocephalus. Thus, NF2 can occasionally be diagnosed in people aged 70 and older, and is characterized by a high prevalence of atypical forms and a low growth potential of tumors, arguing in favor of a wait-and-scan policy as initial management.

Multifocal choroid plexus papillomas: case report.

Choroid plexus papillomas (CPP) are rare tumors of the central nervous system, usually occurring in the ventricular system. Apart from spinal drop metastases, CPPs are generally unique tumors. In this report, the authors present two exceptional adult cases involving multiple benign CPPs located in both intra- and extraventricular locations. The tumors were located in the fourth ventricle and Meckel's cave in one case and the cerebellopontine angle, the frontotemporal region and the fourth ventricle in the other. A review of the literature revealed that these two cases represent the first reported occurrences of multiple choroid plexus papillomas involving Meckel's cave and frontotemporal intraparenchymal locations.

Subsequent mortality in survivors of Ebola virus disease in Guinea: a nationwide retrospective cohort study.

BACKGROUND: A record number of people survived Ebola virus infection in the 2013-16 outbreak in west Africa, and the number of survivors has increased after subsequent outbreaks. A range of post-Ebola sequelae have been reported in survivors, but little is known about subsequent mortality. We aimed to investigate subsequent mortality among people discharged from Ebola treatment units. METHODS: From Dec 8, 2015, Surveillance Active en ceinture, the Guinean national survivors' monitoring programme, attempted to contact and follow-up all survivors of Ebola virus disease who were discharged from Ebola treatment units. Survivors were followed up until Sept 30, 2016, and deaths up to this timepoint were recorded. Verbal autopsies were done to gain information about survivors of Ebola virus disease who subsequently died from their closest family members. We calculated the age-standardised mortality ratio compared with the general Guinean population, and assessed risk factors for mortality using survival analysis and a Cox proportional hazards regression model. FINDINGS: Of the 1270 survivors of Ebola virus disease who were discharged from Ebola treatment units in Guinea, information was retrieved for 1130 (89%). Compared with the general Guinean population, survivors of Ebola virus disease had a more than five-times increased risk of mortality up to Dec 31, 2015 (age-standardised mortality ratio 5·2 [95% CI 4·0-6·8]), a mean of 1 year of follow-up after discharge. Thereafter (ie, from Jan 1-Sept 30, 2016), mortality did not differ between survivors of Ebola virus disease and the general population. (0·6 [95% CI 0·2-1·4]). Overall, 59 deaths were reported, and the cause of death was tentatively attributed to renal failure in 37 cases, mostly on the basis of reported anuria. Longer stays (ie, equal to or longer than the median stay) in Ebola treatment units were associated with an increased risk of late death compared with shorter stays (adjusted hazard ratio 2·62 [95% CI 1·43-4·79]). INTERPRETATION: Mortality was high in people who recovered from Ebola virus disease and were discharged from Ebola treatment units in Guinea. The finding that survivors who were hospitalised for longer during primary infection had an increased risk of death, could help to guide current and future survivors' programmes and in the prioritisation of funds in resource-constrained settings. The role of renal failure in late deaths after recovery from Ebola virus disease should be investigated. FUNDING: WHO, International Medical Corps, and the Guinean Red Cross.

Realization of an Ultra-thin Metasurface to Facilitate Wide Bandwidth, Wide Angle Beam Scanning.

A wide bandwidth, ultra-thin, metasurface is reported that facilitates wide angle beam scanning. Each unit cell of the metasurface contains a multi-resonant, strongly-coupled unequal arm Jerusalem cross element. This element consists of two bent-arm, orthogonal, capacitively loaded strips. The wide bandwidth of the metasurface is achieved by taking advantage of the strong coupling within and between its multi-resonant elements. A prototype of the proposed metasurface has been fabricated and measured. The design concept has been validated by the measured results. The proposed metasurface is able to alleviate the well-known problem of impedance mismatch caused by mutual coupling when the main beam of an array is scanned. In order to validate the wideband and wide scanning ability of the proposed metasurface, it is integrated with a wideband antenna array as a wide angle impedance matching element. The metasurface-array combination facilitates wide angle scanning over a 6:1 impedance bandwidth without the need for bulky dielectrics or multi-layered structures.

Lassa virus-infected rodents in refugee camps in Guinea: a looming threat to public health in a politically unstable region.

Rodent-borne and other communicable diseases are of particular concern to vulnerable populations in complex humanitarian emergencies. We assessed the risk of Lassa fever to refugees and humanitarian aid workers in the Forest Region of Guinea by trapping rodents and testing them for the presence of Lassa virus infection. Our study provides a point prevalence of Lassa virus-infected rodents in various refugee camps in Guinea, suggesting that the risk of disease may be highest in camps further south toward the border with Liberia. The methodology used represents a potential model for rapid public health assessments in the setting of complex humanitarian emergencies.

Spontaneous Intracranial Extradural Hematoma in Sickle Cell Disease.

Spontaneous extradural hematoma is rare in patients with sickle cell disease. We report a clinical case of a 19-year-old young man with sickle cell anemia who presented a sickle cell crisis complicated by the development of multiple acute extradural and subgaleal hematomas that had not been treated surgically. We discuss the physiopathology of this event. Although it is rare, clinicians should be aware of this phenomenon as part of a spectrum of neurologic complications in these patients.

Epidemiology of chronic kidney diseases in the Republic of Guinea; future dialysis needs.

BACKGROUND: Chronic kidney disease (CKD) is increasing worldwide and can lead to end-stage renal disease (ESRD). OBJECTIVES: Because few patients with ESRD in the Republic of Guinea have access to haemodialysis, we retrospectively evaluated the prevalence of CKD, ESRD and access to supportive therapies. PATIENTS AND METHODS: 579 CKD patients (304 males; mean age: 44 ± 16 years) were admitted into Conakry nephrology department, the only centre in the Republic of Guinea, between 2009 and 2013. Most patients (63%) resided within Conakry (the capital), 12.5% came from lower Guinea, 11.7% from middle Guinea, 7.9% from upper Guinea and 4.8% from forest Guinea. RESULTS: Reasons for referral were increased serum creatinine (49.5%), hypertension (27%) and diffuse edema (17%). Also, 11% were diabetic, 12.5% were smokers, 17% were HIV-positive, 8.3% were HBV-positive and 15% were HCV-positive. The most frequent symptom at admission was nausea/vomiting (56%). Upon admission, 70.5% of patients already had ESRD. Although no kidney biopsies were performed it was assumed that 34% and 27% of patients had vascular nephropathy and chronic glomerulonephritis, respectively. Of the 385 ESRD patients, only 140 (36.3%) had access to haemodialysis (two sessions/week, 4 hours each). Most patients that received haemodialysis resided within the Conakry region (P < 0.0001). There were significant associations between mortality and (i) terminal stage of CKD (P = 0.0005), (ii) vascular nephropathy (P = 0.002), and (iii) nephropathies of unknown origin (P = 0.0001). CONCLUSIONS: A fourfold increase in haemodialysis machines is needed in Conakry, plus four new nephrology/haemodialysis centres within the Republic of Guinea, each holding ≥30 haemodialysis machines.

Quality of life of patients with end-stage renal disease in Guinea.

This questionnaire-based study included 69 patients from the Republic of Guinea with end-stage renal disease (ESRD) and was conducted over 12 months. The factors that affected their quality of life (QoL) were determined. The included ESRD patients had an estimated creatinine clearance (CCr) of <15 mL/minute using MDRD formula. We used the SF36 question-naire and classified the results into two groups: Scores<50/100 as poor QoL and scores 50/100 as good QoL. Factors that determined the QoL were cessation of all activities and additional effort required, severe or mild pain, good or bad health, and reduced or not reduced social and physical activities. Of the 69 patients, 32 (46.3%) had a good QoL and 37 (53.7%) had a poor QoL. The estimated CCr was similar in both groups. The average age of the poor QoL group was 54±4 years, the good-QoL group's average age was of 47.6±4 years (P=0.01). Patients with a good QoL had better overall health, but this was not statistically significant [OR=0.42 (0.14-1.28); P=0.14]. Patients with a poor QoL had more severe pain (P=0.002); however, good QoL did not protect against mental problems [OR=46.67 (8.18-351.97); P=0.0001]. Mental status (P=0.01) and social activities (P=0.001) were reduced, and there were more comorbidities in the poor-QoL group (29.7%, with >4, P=0.01). Good QoL was associated with younger age, fewer comorbidities, less severe physical pain, and fewer physical or social limitations. QoL could be increased by improving comorbidity treatments, giving more effective pain control, and providing more assistance for social and physical limitations.

[Nephrotic syndrome in adults: anatomopathological aspects]. / Le syndrome nephrotique de l'adulte: aspects anatomopathologiques.

The objective of this study was to describe the histological features of the nephrotic syndrome in adults, at the Donka National Hospital of the University Hospital of Conakry. This was a prospective study ranging from March 1st 2003 to March 30th 2004, including all patients older than 15 years of age hospitalized for nephrotic syndrome. Twenty patients were selected for the study; 12 men and 8 women, with a sex ratio of 1.5. Ages ranged between 26 and 40 years with a mean of 26.2 ± 8.1 years. Seven patients were between the ages of 21 and 25 .All patients had normal renal function and normal blood count.All viral serology tests were negative. The glomerular lesions observed were segmental and focal glomerular sclerosis in 40%, followed by minimal glomerular lesions for 35%, membranous glomerulonephritis in 5% of the cases and in 15% of the cases, the lesions were indeterminate.Further studies should be done on a greater scale on one hand, and on the other move towards finding the primary or secondary causes of these glomerulopathies.

L'objectif de cette étude était de décrire les aspects histologiques du syndrome néphrotique de l'adulte, à l'Hôpital National Donka du CHU de Conakry.Il s'agissait d'une étude prospective et descriptive allant du 1er Mars 2003 au 30 Mars 2004 incluant tous les patients âgés de plus de 15 ans hospitalisés pour syndrome néphrotique. Vingt malades ont été retenus pour l'étude. Ils se répartissaient en 12 hommes et 8 femmes, soit un sex ratio de 1,5. Leur âge était compris entre 16 et 40 ans avec une moyenne de 26,2 ± 8,1 ans. L'âge de 7 patients était compris entre 21 et 25 ans. Tous les patients avaient une fonction rénale normale et un hémogramme normal. Toutes les sérologies virales étaient négatives. Les lésions glomérulaires observées étaient une hyalinose segmentaire et focale dans 40%, suivie des lésions glomérulaires minimes dans 35% des cas, une glomérulonéphrite membranoproliférative dans 5% des cas, une glomérulonéphrite extramembraneuse dans 5% des cas et dans 15% des cas, les lésions étaient indéterminées. Des études ultérieures devraient intéresser un recrutement plus important de patients d'une part, et d'autre part s'orienter vers la recherche de la nature primitive ou secondaire de ces glomérulopathies.

Conservative management of bilateral vestibular schwannomas in neurofibromatosis type 2 patients: hearing and tumor growth results.

BACKGROUND: As new treatment modalities develop for the management of vestibular schwannomas (VS) in patients with neurofibromatosis type 2, it remains crucial to ascertain the natural history of the disease. OBJECTIVE: To determine the relationship between hearing and tumor growth in patients undergoing conservative VS management. METHODS: Patients harboring bilateral VS with at least 1 year of radiological follow-up were selected. Conservative management was proposed based on the small tumor size and/or serviceable hearing at presentation. Tumor size was calculated by using the 2-component box model and reported as mean tumor diameter. Hearing was evaluated by using pure-tone average and the American Academy of Otololaryngologists and Head and Neck Surgery classification. RESULTS: Forty-six patients harboring 92 VS were included. The mean clinical and radiological follow-up times were 6.0 and 4.2 years, respectively. The mean tumor diameter was 13 mm at presentation and 20 mm at the end of follow-up. Mean tumor growth rate was 1.8 mm/year. During follow-up, 17 patients (37%) underwent surgery for VS. Surgery-free rate for VS was 88% at 5 years. The number of patients with at least 1 serviceable ear was 39 (85%) at presentation and 34 (74%) at the end of follow-up, including 22 (66%) with binaural serviceable hearing maintained. There was no statistical correlation between tumor growth rate and preservation of serviceable hearing. Tumor growth rates and age at presentation were inversely correlated. CONCLUSION: This study illustrates the high variability among neurofibromatosis type 2 patients regarding hearing status and VS growth rate and justifies the choice of initial conservative management in selected cases. ABBREVIATIONS: : AAO-HNS, American Academy of Otololaryngologists and Head and Neck Surgery classificationMTD, mean tumor diameterNF2, neurofibromatosis type 2PTA, pure-tone averageSDS, speech discrimination scoreVS, vestibular schwannomas.

[Life quality in patients at terminal stage of chronic renal failure with no access to dialysis]. / Etude de la qualite de vie des patients au stade terminal de l'insuffisance renale chronique sans acces a la dialyse.

A transversal prospective study of 69 patients with terminal stage renal disease covering a 12 month period - 1st January to 31st December 2010 - was conducted; the objective was to determine factors affecting their quality of life.This is a questionnaire study covering a 12 month period. The study group were patients with ESRD whose clearance of creatinin were less than 15ml/min. patients who died shortly after arrival, those with acute renal failure and those undergoing dialysis were excluded.We used the SF36 questionnaire [8] and classified the results in two groups: scores lower than 50/100=poor quality of life, scores exceed or equal to 50/100=good quality of life. Factors making quality of life also into two groups; for limitations: cessation of all activities and additional effort required; for pain: severe and mild; for health: good and bad; for social and physical activities: reduced and not reduced.Terminal stage renal disease represents 30.8% of admissions in 12 months, for a total of 69 patients. Thirty-two (46.3%) had good quality of life and 37 (53.7%) poor quality of life. In the latter group, the average age was of 54±4, while in the good quality of life group: the average age was 47.6 ± 4 (p=0.01). Patients in the good quality of life group had better health overall (OR=0.42). Poor quality of life patients had more severe pain (p=0.001); however good quality of life didn't protect against mental problems (p=0.866). Limitations due to mental status were more frequent at the poor quality of life (p=0.01). Social activities were more reduced in the poor quality of life group (p=0.0001) and there were more co-morbidities (29.7% with more than 4).In our study good quality of life is associated with younger age, fewer comorbidities, less severe physical pain and fewer physical plus social limitations. Quality of life could substantially be improved by acting on modifiable factors such as better treatment for the co-morbidities, more effective pain control and assistance with their social and physical limitations.

Il s'agit d'une étude prospective de type transversale qui s'est déroulée du 01 janvier au 31 décembre 2010 ; l'objectif était d'évaluer la qualité de vie des patients au stade d'insuffisance rénale chronique terminale n'ayant pas accès à la dialyse dans le service de Néphrologie de l'hôpital national Donka.Nous avons utilisé le questionnaire SF36 (1). Cette échelle donne deux scores, l'un relatif à la santé physique et l'autre à la santé psychique ; chaque dimension est notée de 0 à 100 : plus le score est élevé, meilleure est la qualité de vie. Les patients ont été répartis en deux groupes selon le score obtenu : s'il est inférieur à la moyenne (50/100) le patient est classé non autonome, s'il est supérieur ou égal à 50/100 le patient est classé autonome. Les comorbidités ont été dénombrées par patient et classées de 0 ­ 4 et plus. Les paramètres étudiés étaient essentiellement cliniques.Soixante neufs patients ont été retenus pour l'étude. Ils étaient 37 (53,6%) hommes et 32 (46,4%) femmes. L'âge moyen des hommes était de 50,97 ± 2,91ans avec des extrêmes de 15 et 85 ans. L'âge moyen des femmes était de 48 ± 3,13ans avec des extrêmes de 18 et 94 ans. Trente deux patients (46,3%) avaient une bonne qualité de vie et 37 (53,7%) avec une mauvaise qualité de vie. Dans ce dernier groupe l'âge moyen était de 54 ± 4ans tandis que dans l'autre il était de 47,6 ± 4ans (p=0,01).Les patients ayant une meilleure qualité de vie étaient en meilleure santé (OR=0,42) et la douleur physique peu intense malgré cela ils n'étaient pas à l'abri de souffrance psychique (p=0.866). Ceux avec une mauvaise qualité de vie avaient une douleur physique plus intense (p=0,001) et les limitations dues à l'état mental plus marquées. Les relations sociales y étaient plus réduites (p=0,0001) et les comorbidités plus nombreuses (plus de 29,7% avec plus de 4 comorbidités).La meilleure qualité de vie est associée à l'âge plus jeune, peu de comorbidités, une faible douleur physique et des relations sociales conservées. Elle peut être améliorée en agissant sur les facteurs modifiables tels que la meilleure prise en charge des comorbidités et de la douleur, une assistance sociale et professionnelle.

Differential MRI analysis for quantification of low grade glioma growth.

A differential analysis framework of longitudinal FLAIR MRI volumes is proposed, based on non-linear gray value mapping, to quantify low-grade glioma growth. First, MRI volumes were mapped to a common range of gray levels via a midway-based histogram mapping. This mapping enabled direct comparison of MRI data and computation of difference maps. A statistical analysis framework of intensity distributions in midway-mapped MRI volumes as well as in their difference maps was designed to identify significant difference values, enabling quantification of low-grade glioma growth, around the borders of an initial segmentation. Two sets of parameters, corresponding to optimistic and pessimistic growth estimations, were proposed. The influence and modeling of MRI inhomogeneity field on a novel midway-mapping framework using image models with multiplicative contrast changes was studied. Clinical evaluation was performed on 32 longitudinal clinical cases from 13 patients. Several growth indices were measured and evaluated in terms of accuracy, compared to manual tracing. Results from the clinical evaluation showed that millimetric precision on a specific volumetric radius growth index measurement can be obtained automatically with the proposed differential analysis. The automated optimistic and pessimistic growth estimates behaved as expected, providing upper and lower bounds around the manual growth estimations.

Long-term follow-up of 287 meningiomas in neurofibromatosis type 2 patients: clinical, radiological, and molecular features.

Decision-making criteria for optimal management of meningiomas in neurofibromatosis type 2 (NF2) patients is hampered by lack of robust data, particularly long-term natural history. Seventy-four NF2 patients harboring 287 cranial meningiomas followed up for a mean period of 110.2 months were studied retrospectively. The median number of meningiomas per patient was 3. The mean maximum diameter of meningiomas at diagnosis was 14.3 mm, with a mean annual growth rate of 1.5 mm. Sixty-six percent of tumors showed no or minimal growth. In a subgroup of patients with 3D MRI, 7.3% of meningiomas (28% of patients) had a volumetric growth rate 20% or more per year. Twenty-five de novo meningiomas appeared during the follow-up (8.7%) and demonstrated a higher growth rate than other meningiomas (6.6 mm/year). Fifty-six meningiomas (23%) in 34 NF2 patients (45.9%) were operated on during the follow-up period. Among symptomatic resected meningiomas, grades II and III tumors were found in 29% and 6% of cases, respectively, with a remarkable intratumor histological heterogeneity. Single nucleotide polymorphism array analysis of 22 meningioma samples in 14 NF2 patients showed increasing chromosome instability with increasing grade, the most frequent losses being on 22q, 1p, 18q, and 6p. This study provides clues to improve tailored treatment of meningiomas: de novo and brain edema-associated meningiomas require active treatment. Future clinical trials in NF2 need to focus specifically on meningiomas as the primary endpoint and should include patients with meningiomas growing 20% or more per year in order to assess new treatments.