458 research outputs found
Lhermitte′s Sign: The Current Status
No full textLhermitte′s sign was described by Marie and Chatelin and named after Jean Lhermitte. This sign is mostly described as an electric shock like condition by some patients of multiple sclerosis. This sensation occurs when the neck is moved in a wrong way or rather flexed. It can also travel down to the spine, arms, and legs, and sometimes the trunk. Demyelination and hyperexcitability are the main pathophysiological reasons depicted for the Lhermitte′s sign. Other causes for Lhermitte′s sign include transverse myelitis, behηet′s disease, trauma, etc. This article reviews the Lhermitte′s sign, its history, and its etiopathophysiology. Very few studies are available on Lermitte′s sign and more research need to be done on the same to ensure its sensitivity and specificity
Case Report Lhermitte's Sign Developing after IMRT for Head and Neck Cancer
No full textBackground. Lhermitte's sign (LS) is a benign form of myelopathy with neck flexion producing an unpleasant electric-shock sensation radiating down the extremities. Although rare, it can occur after head and neck radiotherapy. Results. We report a case of Lhermitte's developing after curative intensity-modulated radiotherapy (IMRT) for a patient with locoregionally advanced oropharyngeal cancer. IMRT delivers a conformal dose of radiation in head and neck cancer resulting in a gradient of radiation dose throughout the spinal cord. Using IMRT, more dose is delivered to the anterior spinal cord than the posterior cord. Conclusions. Lhermitte's sign can develop after IMRT for head and neck cancer. We propose an anterior spinal cord structure, the spinothalamic tract to be the target of IMRT-caused LS
Lhermitte-duclos disease related with cowden syndrome mimicking metastatic lung cancer on FDG PET/CT
No full textCopyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.ABSTRACT: Cowden syndrome is characterized by multiple hamartomatous and neoplastic lesions including Lhermitte-Duclos disease, which is the main criterion for the diagnosis. Herein, we presented a patient with suspected metastatic disease referred to PET/CT, which showed mildly hypermetabolic multinodular thyroid goiter, multiple hamartomatous pulmonary, and breast nodules. Also, intense hypermetabolism was noted on the cerebellar tumor lesion. Lhermitte-Duclos disease was diagnosed based on the characteristic MRI findings, and she was followed up with a diagnosis of Cowden syndrome. Our case indicates that Cowden syndrome should be included as a differential diagnosis of abnormal FDG uptake in the multiple systemic hamartomatous tumors
Frequency and predictors of lhermitte phenomenon in multiple sclerosis (2-year prospective study)
No full textНейропатичний біль при розсіяному склерозі може проявлятися у вигляді феномену Лермітта – короткочасні неприємні відчуття вздовж хребта, які виникають при згинанні голови. Метою даного дослідження є вивчення факторів, що виступають в якості предикторів феномену Лермітта та їх частоти при розсіяному склерозі. В процес дослідження залучено 308 пацієнт з розсіяним склерозом, з них 258 погодилися на подальше спостереження - 67 чоловіків (26,0%) та 191 жінок (74,0%), віком від 21 до 60 років; у 187 (72,5%) випадках був рецидивно-ремітучий, у 2 (0,8%) випадках – первинно прогресуючий та у 69 (26,7%) випадку – вторинно прогресуючий тип РС. Серед 258 пацієнтів, які після початкового огляду в Центрі погодилися на подальшу співпрацю, 18 (7,0%) осіб протягом 1-го року та 13 (5,0%) осіб протягом 2-го року достроково за різними причинами припинили участь у дослідженні. Серед характеристик розсіяного склерозу визначали вік пацієнта, коли був діагностований, тривалість захворювання, тип перебігу, сумарну оцінку неврологічного дефіциту. Використовувалися відповідні шкали для визначення психопатологічних та когнітивних станів, враховувалися соціально-демографічні чинники та коморбідна патологія, статистичні методи дослідження. Було встановлено, що ризик розвитку феномену Лермітта є практично однаковим протягом двох років: 1-й рік – 2,5%, 2-й рік – 2,3%. Больові відчуття при феномені Лермітта частіше локалізуються у шиї частотою 63,6%, верхній частині спини – 54,6%, нижній частині спини – 72,7%, а найрідше у верхніх кінцівках – 18,2% та нижніх кінцівках – 36,4%. Здебільшого топічно феномен Лермітта розповсюджується на дві або три уражені ділянки тіла 33,3% та 48,2% відповідно. Найчастішим дескриптором при феномені Лермітта є «простріл» - 72,7%, «поколювання» – 18,2%, «повзання мурашок» - 9,1%. Не спостерігається достовірних відмінностей у соціальних, демографічних, нейропсихологічних та нейрокогнітивних характеристиках між пацієнтами з феноменом Лермітта та без нього. За результатами однофакторного регресійного аналізу Кокса виявлено, що протягом 2-х річного періоду збільшення тривалості захворювання на кожен наступний рік асоціюється зі зменшенням відносного ризику виникнення феномену Лермітта в 1,15 разів (1,02-1,29, р=0,02). Отже, у пацієнтів з розсіяним склерозом протягом кожного року захворювання середній ризик виникнення феномену Лермітта становить 2,3-2,5%. Пацієнти, які мають нетривалий стаж розсіяного склерозу є групою ризику щодо виникнення феномену Лермітта. Виявлену нами закономірність досить важко пояснити, для її уточнення необхідне детальне вивчення спеціального додаткового дослідження. Але, в усякому випадку, з практичної точки зору, пацієнтів на ранніх стадіях розсіяного склерозу можна розглядати як групу підвищеного ризику щодо виникнення феномену Лермітта.Neuropathic pain in multiple sclerosis can manifest itself in the form of the Lhermitte phenomenon, short-term unpleasant sensations along the spine that occur when the head is bent. The purpose of this study is to investigate the factors that act as predictors of the Lhermitte phenomenon and their frequency in multiple sclerosis. 308 patients with multiple sclerosis were involved in the study, 258 of them agreed to follow-up, of them there were 67 men (26.0%) and 191 women (74.0%), aged 21 to 60 years. Out of the total cases, 187 (72.5%) patient had the relapsing-remitting type of multiple sclerosis, 2 (0.8%) had primary progressive type, and 69 (26.7%) showed secondary progressive type. Among the 258 patients who initially agreed to participate in the study at the Centre, 18 (7.0%) individuals discontinued their involvement during the first year, and 13 (5.0%) individuals prematurely withdrew from the study during the second year due to various reasons.
Among the characteristics of multiple sclerosis, the age of the patient when diagnosed, the duration and the type of course, and the overall assessment of neurological deficit were determined. Psychopathological and cognitive states, socio-demographic factors, and comorbid pathology were assessed using appropriate scales. Statistical research methods were employed to analyze the collected data.
The results indicate that the risk of developing the Lhermitte phenomenon remains relatively consistent over a two-year period: 2.5% in the first year and 2.3% in the second year. Pain associated with the Lhermitte phenomenon is most commonly experienced in the neck (63.6%), followed by the upper back (54.6%), lower back (72.7%), and least frequently in the upper limbs (18.2%) and lower limbs (36.4%). The Lhermitte phenomenon typically spreads to two or three affected areas of the body in 33.3% and 48.2% of cases, respectively. The most commonly used descriptors for the Lhermitte phenomenon are "shooting" (72.7%), "tingling" (18.2%), and "crawling ants" (9.1%).
No significant differences in social, demographic, neuropsychological, and neurocognitive characteristics were observed between patients with and without Lhermitte phenomenon. According to the results of univariate Cox regression analysis, we has found that during the 2-year period, an increase in the duration of the disease for each subsequent year is associated with a decrease in the relative risk of Lhermitte phenomenon by 1.15 times (1.02-1.29, p=0.02). In patients with multiple sclerosis, the average risk of experiencing the Lhermitte phenomenon remains consistent at approximately 2.3-2.5% per year throughout the course of the disease.
Patients who have a short history of multiple sclerosis are a risk group for the occurrence of the Lhermitte phenomenon. It is quite difficult to explain the regularity we have identified, for its clarification a detailed study of a special additional study is necessary. But, in any case, from a practical point of view, patients in the early stages of multiple sclerosis can be considered as a group of increased risk for the occurrence of the Lhermitte phenomenon
Lhermitte–Duclos Disease Mimicking Cerebellopontine Angle Tumor: A Case Report
No full textLhermitte-Duclos disease (LDD) is dysplastic gangliocytoma of the cerebellum, which is rare, tends to grow slowly, usually has good prognosis, and wherein the cerebellar cortex becomes thick and the central white matter is not observed. On MRI of the brain, it has hyperintense and hypointense presentations on T2- and T1-weighted scans, respectively. It has nonhomogenous contrasting pattern on T1-contrast scans. LDD can be seen unilaterally or bilaterally in the cerebellum. When the disease is located at the cerebellopontine angle, it can be mistaken for the tumors located in this region. Recurrence can occur postoperatively, which is rare. The present case is a rare one because the tumor was located at the cerebellopontine angle and radiologically mimicked cerebellopontine angle tumors
Deep Learning Regional Climate Model Emulators: a comparison of two downscaling training frameworks [datasets]
No full textOutputs used in:
van der Meer, M., de Roda Husman, S., Lhermitte, S.: Deep Learning Regional Climate Model Emulators: a comparison of two downscaling training frameworks
MAR(ACCESS1-3)_monthly_SMB.nc: MAR outputs with monthly values of SMB and components over the Antarctic ice sheet (1980--2100)
MAR(ACCESS1-3)-stereographic_monthly_GCM_like.nc: MAR outputs upscaled to GCM resolution (1980--2100)
ACCESS1-3-stereographic_monthly_cleaned.nc: GCM monthly outputs over the Antarctic ice sheet (1980--2100)
The up-to-date working versions of our experiments and source code can be found and are available on our GitHub: https://github.com/marvande/RCM-Emulator and at this link: https://doi.org/10.5281/zenodo.7875967
Data usage notice:
If you use any of these results, please acknowledge the work of the people involved in producing them. You should also refer to and cite the following paper:
Cite as: Marijn van der Meer, Sophie de Roda Husman, S Lhermitte. Deep Learning Regional Climate Model Emulators: a comparison of two downscaling training frameworks. Authorea. December 27, 2022
DOI: 10.22541/essoar.167214210.02213149/v
Lhermitte-Duclos disease in 3 children: A clinical long-term observation
No full textWe report three boys in whom a diagnosis of Lhermitte-Duclos disease (LDD) was assumed from characteristic neuroimaging findings. LDD was confirmed by an open biopsy in patient 1, while a biopsy in patient 2 was inconclusive. Histologic confirmation in patient 3 was deliberately not attempted. However, a follow-up observation of stable clinical and neuroimaging findings over 2, 5 and 11 years, respectively, support the diagnosis of LDD. Despite extensive expansion of the lesion with brainstem involvement, clinical signs in two boys were minimal, while one patient has cognitive impairment and a complex oculomotor disturbance. So far we found no evidence for an association with Cowden disease (CD). No germline PTEN mutations were detected in these children, but the amount of available biopsy tissue in patients 1 and 2 was insufficient for a complete genetic analysis of tumor tissue. In conclusion, LDD can usually be diagnosed by MRI. In view of the favourable natural history, a conservative “wait and see” strategy is justified, particularly if radical tumor resection is not possible. LDD is often not associated with CD and germline PTEN mutations seem not to be present in isolated LDD
Science et foi, par P. Chauchard, R. Chauvin, O. Costa de Beauregard, D. Dubarle, O. P., A. George, P. Germain, J.-L. Kahn, R. Lavocat, P. Lejay, S. J., R. Lennuier, L. Leprince-Ringuet, J. Lhermitte, G. Mangenot, M. Polonovski, P. Ricœur, Ph. Roqueplo, O. P., F. Russo, S. J
No full textRobert Jean-Dominique. Science et foi, par P. Chauchard, R. Chauvin, O. Costa de Beauregard, D. Dubarle, O. P., A. George, P. Germain, J.-L. Kahn, R. Lavocat, P. Lejay, S. J., R. Lennuier, L. Leprince-Ringuet, J. Lhermitte, G. Mangenot, M. Polonovski, P. Ricœur, Ph. Roqueplo, O. P., F. Russo, S. J. In: Revue Philosophique de Louvain. Troisième série, tome 63, n°78, 1965. p. 304
How to reduce sampling errors in spaceborne cloud radar-based snowfall estimates
No full textSnowfall is an important climate change indicator affecting surface albedo, glaciers, sea ice, freshwater storage, cloud lifetime, and ecosystems. Precise snowfall measurements at high latitudes are particularly important for the estimation of the mass balance of ice sheets; however, the snowfall is difficult to quantify with in situ measurements in those locations. In this context, spaceborne radar and radiometer atmospheric missions can help in the assessment of snowfall at high latitudes. The decommissioned NASA CloudSat mission provided invaluable information about global snowfall climatology from 2006 to 2023. The CloudSat-based estimates of global snowfall are considered the reference for global snowfall estimates, but these data suffer from poor sampling and the inability to see shallow or retrieve heavy precipitation, which limits their use, for example, as input to surface mass balance models of the major ice sheets. WIVERN (WInd VElocity Radar Nephoscope), one of the ESA Earth Explorer 11 selected missions, is equipped with a conical scanning 94 GHz Doppler radar and a passive 94 GHz radiometer, with the main objective of measuring global in-cloud horizontal winds, but also quantifying cloud ice water content and precipitation rate. Its conically scanning system, with a 42° incidence angle, is expected to reduce the radar blind zone near the surface (especially over the ocean) and allows the mission to have a swath width of 800 km and 70 times more sampled points than a fixed-looking instrument. The proposed radar measurements tackle the current uncertainties in snowfall estimates, highly improving the sampling frequency and accuracy of snowfall measurements. The uncertainty in snowfall measurements arises from various factors, including the diurnal cycle, uncertainty in the Z–S relationship, and the sampling error. This study quantifies each of these contributors individually and demonstrates the improved sampling capabilities of the WIVERN conically scanning geometry for some specific regions (Antarctica, Greenland) by computing the sampling error at different spatial and temporal scales via simulations of WIVERN vs. CloudSat orbits and scanning geometry, based on the snowfall rates produced by ERA5 reanalysis.
Results show that a WIVERN-like conically scanning system significantly reduces the uncertainty in polar snowfall estimates if compared to a CloudSat-like near-nadir fixed viewing geometry. While CloudSat generates acceptable errors at the annual zonal scales, WIVERN can produce estimates within the climatological variability for latitude–longitude domain larger than 0.5° × 0.5° already at the monthly timescale, making it a valuable product for regional climate model evaluation and as an input to surface mass balance models of the major ice sheets and glaciers
Lhermitte-Duclos disease (dysplastic cerebellar gangliocytoma): Review of the literature
No full textOBJECTIVES: Lhermitte-Duclos disease (LDD), or dysplastic gangliocytoma of the cerebellum is a rare benign unilateral mass of the cerebellar cortex, characterized by a disarrangement of the normal cerebellar laminar cytoarchitecture and circumscribed enlargement of cerebellar folia. LDD was recently considered to be part of a multiple hamartoma-neoplasia syndrome [Cowden disease (CD)]. The debate whether LDD represents a neoplastic or hamartomatous lesion is still in progress. METHODS: The aim of the present study is to answer this question with review of the literature emphasize on clinical presentation, radiologic findings, surgical procedures, and histopathologic features of LDD. RESULTS: LDD most frequently presents in the third and fourth decades of life, but the age at clinical manifestation ranges from the neonatal period to the seventh decade. The initial presentation of LDD, similar to other posterior fossa tumors, includes increased intracranial pressure, vomiting, intermittent headache, cerebellar dysfunction, and noncommunicating hydrocephalus. Magnetic resonance imaging is the diagnostic modality and reveals characteristic usually nonenhancing gyriform patterns with enlargement of cerebellar folia. Surgical excision is a therapeutic procedure generally performed. The histopathologic findings of LDD include thickening of the molecular layer, which is occupied by abnormal ganglion cells, absence of the Purkinje cell layer, and hypertrophy of the granule cell layer. CONCLUSIONS: LDD is an unusual hamartomatous lesion of the cerebellar cortex, which can be associated with CD. When the diagnosis of either one of these 2 disorders is established, it is imperative to search for the other disease, to detect early malignant lesions that occur in CD. © 2007 Lippincott Williams & Wilkins, Inc
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