Actualización en el diagnóstico de la encefalitis / Update on the diagnosis of encephalitis

Las encefalitis autoinmunes son procesos inflamatorios cerebrales que se clasifican en dos grandes grupos según el mecanismo patogénico subyacente: las mediadas por anticuerpos vs. antígenos intracelulares (paraneoplásicas) y las mediadas por anticuerpos frente a los antígenos extracelulares o de superficie neuronal. Las manifestaciones clínicas son muy variadas y poco específicas. Las pruebas complementarias incluidas en el diagnóstico clínico de la encefalitis autoinmune incluyen, entre otras, la determinación de anticuerpos en suero o en líquido cefalorraquídeo y la resonancia magnética (RM). La RM puede presentar patrones característicos como la afectación mesial del temporal, aunque en determinados casos puede ser normal. La imagen de tomografía por emisión de positrones (PET/TC) con 18F-Fluorodeoxiglucosa (18F-FDG PET/TC) puede ser de gran utilidad en los casos de encefalitis autoinmunes paraneoplásicas para encontrar el tumor primario. En los casos de encefalitis autoinmunes mediadas por anticuerpos frente a los antígenos extracelulares, la 18F-FDG PET/TC presenta unos patrones que pueden ayudar al diagnóstico clínico. Esta colaboración especial pretende presentar de forma clara y de fácil comprensión las características clínicas de la encefalitis autoinmune, las dificultades en el diagnóstico clínico y los patrones observados en la RM y en la 18F-FDG PET/TC (AU)

Autoimmune encephalitis are brain inflammatory processes that are classified into two main groups according to the underlying pathogenic mechanism: antibodies to intracellular antigens (paraneoplastic) and antibodies to extracellular or neuronal surface antigens. The clinical manifestations of autoimmune encephalitis are very varied and non-specific. Complementary tests included in its clinical diagnosis include determination of antibodies in serum or cerebrospinal fluid and magnetic resonance imaging (MRI). MRI may show characteristic patterns such as mesial temporal involvement, although in some cases it may be normal or non-specific. 18F-Fluorodeoxyglucose PET/CT (18F-FDG PET/CT) imaging may be helpful in cases of paraneoplastic autoimmune encephalitis to find the primary tumor. In autoimmune encephalitis mediated by antibodies to extracellular antigens, 18F-FDG PET/CT shows distinctive patterns that can aid clinical diagnosis. This special collaboration aims to present in a clear and easy-to-understand way, the clinical features of autoimmune encephalitis, the difficulties in clinical diagnosis and the patterns seen on MRI and 18F-FDG PET/CT (AU)

Update on the diagnosis of encephalitis.

Autoimmune encephalitis are brain inflammatory processes that are classified into two main groups according to the underlying pathogenic mechanism: antibodies to intracellular antigens (paraneoplastic) and antibodies to extracellular or neuronal surface antigens. The clinical manifestations of autoimmune encephalitis are very varied and non-specific. Complementary tests included in its clinical diagnosis include determination of antibodies in serum or cerebrospinal fluid and magnetic resonance imaging (MRI). MRI may show characteristic patterns such as mesial temporal involvement, although in some cases it may be normal or non-specific. 18F-Fluorodeoxyglucose PET/CT (18F-FDG PET/CT) imaging may be helpful in cases of paraneoplastic autoimmune encephalitis to find the primary tumor. In autoimmune encephalitis mediated by antibodies to extracellular antigens, 18F-FDG PET/CT shows distinctive patterns that can aid clinical diagnosis. This continuing education aims to present in a clear and easy-to-understand way, the clinical features of autoimmune encephalitis, the difficulties in clinical diagnosis and the patterns seen on MRI and 18F-FDG PET/CT.

Semi-quantification and grading of amyloid PET: A project of the European Alzheimer's Disease Consortium (EADC).

BACKGROUND: amyloid-PET reading has been classically implemented as a binary assessment, although the clinical experience has shown that the number of borderline cases is non negligible not only in epidemiological studies of asymptomatic subjects but also in naturalistic groups of symptomatic patients attending memory clinics. In this work we develop a model to compare and integrate visual reading with two independent semi-quantification methods in order to obtain a tracer-independent multi-parametric evaluation. METHODS: We retrospectively enrolled three cohorts of cognitively impaired patients submitted to 18F-florbetaben (53 subjects), 18F-flutemetamol (62 subjects), 18F-florbetapir (60 subjects) PET/CT respectively, in 6 European centres belonging to the EADC. The 175 scans were visually classified as positive/negative following approved criteria and further classified with a 5-step grading as negative, mild negative, borderline, mild positive, positive by 5 independent readers, blind to clinical data. Scan quality was also visually assessed and recorded. Semi-quantification was based on two quantifiers: the standardized uptake value (SUVr) and the ELBA method. We used a sigmoid model to relate the grading with the quantifiers. We measured the readers accord and inconsistencies in the visual assessment as well as the relationship between discrepancies on the grading and semi-quantifications. CONCLUSION: It is possible to construct a map between different tracers and different quantification methods without resorting to ad-hoc acquired cases. We used a 5-level visual scale which, together with a mathematical model, delivered cut-offs and transition regions on tracers that are (largely) independent from the population. All fluorinated tracers appeared to have the same contrast and discrimination ability with respect to the negative-to-positive grading. We validated the integration of both visual reading and different quantifiers in a more robust framework thus bridging the gap between a binary and a user-independent continuous scale.

Plasma Aß42/40 Ratio Detects Early Stages of Alzheimer's Disease and Correlates with CSF and Neuroimaging Biomarkers in the AB255 Study.

BACKGROUND: Easily accessible biomarkers are needed for the early identification of individuals at risk of developing Alzheimer's disease (AD) in large population screening strategies. OBJECTIVES: This study evaluated the potential of plasma ß-amyloid (Aß) biomarkers in identifying early stages of AD and predicting cognitive decline over the following two years. DESIGN: Total plasma Aß42/40 ratio (TP42/40) was determined in 83 cognitively normal individuals (CN) and 145 subjects with amnestic mild cognitive impairment (a-MCI) stratified by an FDG-PET AD-risk pattern. RESULTS: Significant lower TP42/40 ratio was found in a-MCI patients compared to CN. Moreover, a-MCIs with a high-risk FDG-PET pattern for AD showed even lower plasma ratio levels. Low TP42/40 at baseline increased the risk of progression to dementia by 70%. Furthermore, TP42/40 was inversely associated with neocortical amyloid deposition (measured with PiB-PET) and was concordant with the AD biomarker profile in cerebrospinal fluid (CSF). CONCLUSIONS: TP42/40 demonstrated value in the identification of individuals suffering a-MCI, in the prediction of progression to dementia, and in the detection of underlying AD pathology revealed by FDG-PET, Amyloid-PET and CSF biomarkers, being, thus, consistently associated with all the well-established indicators of AD.

PET amiloide en enfermedades neurodegenerativas que cursan con demencia / Amyloid PET in neurodegenerative diseases with dementia

La enfermedad de Alzheimer (EA) es una enfermedad neurodegenerativa que se caracteriza por un deterioro cognitivo progresivo y pérdida de memoria, siendo la causa más común de demencia. Los hallazgos anatomopatológicos de la EA son los depósitos de Aβ amiloide y proteína Tau, que producen disfunción sináptica y muerte neuronal. La PET amiloide es una técnica útil, disponible y no invasiva que nos proporciona información in vivo del depósito amiloide. En las últimas revisiones de los criterios diagnósticos de la EA se definen e incorporan los biomarcadores, que se clasifican en biomarcadores fisiopatológicos o de diagnóstico (aumento de la retención fibrilar amiloide observada por PET o disminución del péptido Aβ1-42 y elevación de las proteínas T-Tau y F-Tau en el LCR) y biomarcadores de neurodegeneración o topográficos (disminución del metabolismo temporoparietal en la PET-FDG y atrofia temporal medial en la RM). Recientemente se han creado unas recomendaciones específicas para la correcta utilización de los biomarcadores, donde se incluye la PET amiloide: deterioro cognitivo persistente/progresivo, deterioro cognitivo atípico, deterioro cognitivo de inicio precoz y diagnóstico diferencial entre EA y otras enfermedades neurodegenerativas que cursan con demencia. Nuevos estudios de investigación y ensayos clínicos están utilizando la PET amiloide en la evaluación y el desarrollo de nuevas terapias para la EA, así como para el estudio de otras enfermedades neurodegenerativas que cursan con demencia. En este trabajo revisamos algunos conceptos generales y profundizamos en el uso de esta nueva técnica y su relación con las enfermedades neurodegenerativas y el resto de las técnicas diagnósticas

Alzheimer's disease (AD) is a neurodegenerative condition characterized by progressive cognitive decline and memory loss, and is the most common form of dementia. Amyloid plaques with neurofibrillary tangles are a neuropathological hallmark of AD that produces synaptic dysfunction and culminates later in neuronal loss. Amyloid PET is a useful, available and non-invasive technique that provides in vivo information about the cortical amyloid burden. In the latest revised criteria for the diagnosis of AD biomarkers were defined and integrated: pathological and diagnostic biomarkers (increased retention on fibrillar amyloid PET or decreased Aβ1-42 and increased T-Tau or P-Tau in CSF) and neurodegeneration or topographical biomarkers (temporoparietal hypometabolism on 18F-FDG PET and temporal atrophy on MRI). Recently specific recommendations have been created as a consensus statement on the appropriate use of the imaging biomarkers, including amyloid PET: early-onset cognitive impairment/dementia, atypical forms of AD, mild cognitive impairment with early age of onset, and to differentiate between AD and other neurodegenerative diseases that occur with dementia. Amyloid PET is also contributing to the development of new therapies for AD, as well as in research studies for the study of other neurodegenerative diseases that occur with dementia where the deposition of Aβ amyloid is involved in its pathogenesis. In this paper, we review some general concepts and study the use of amyloid PET in depth and its relationship with neurodegenerative diseases and other diagnostic techniques

Consensus document on the progression and treatment response criteria in gastroenteropancreatic neuroendocrine tumors

Purpose: Gastroenteropancreatic neuroendocrine tumors are a heterogeneous group of low incidence neoplasms characterized by a low proliferative activity and slow growth. Their response to targeted therapies is heterogeneous and often does not lead to tumor shrinkage. Thus, evaluation of the therapeutic response should differ from other kind of tumors. Methods: To answer relevant questions about which techniques are best in the assessment of progression or treatment response a RAND/UCLA-based consensus process was implemented. Relevant clinical questions were listed followed by a systematic search of the literature. The expert panel answered all questions with recommendations, combining available evidence and expert opinion. Recommendations were validated through a questionnaire and a participatory meeting. Results: Expert recommendations regarding imaging tools for tumor assessment and evaluation of progression were agreed upon. Available imaging techniques were reviewed and recommendations for best patient monitoring practice and the best way to evaluate treatment response were formulated

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European Association of Nuclear Medicine and European Academy of Neurology recommendations for the use of brain 18 F-fluorodeoxyglucose positron emission tomography in neurodegenerative cognitive impairment and dementia: Delphi consensus.

BACKGROUND AND PURPOSE: Recommendations for using fluorodeoxyglucose positron emission tomography (FDG-PET) to support the diagnosis of dementing neurodegenerative disorders are sparse and poorly structured. METHODS: Twenty-one questions on diagnostic issues and on semi-automated analysis to assist visual reading were defined. Literature was reviewed to assess study design, risk of bias, inconsistency, imprecision, indirectness and effect size. Critical outcomes were sensitivity, specificity, accuracy, positive/negative predictive value, area under the receiver operating characteristic curve, and positive/negative likelihood ratio of FDG-PET in detecting the target conditions. Using the Delphi method, an expert panel voted for/against the use of FDG-PET based on published evidence and expert opinion. RESULTS: Of the 1435 papers, 58 papers provided proper quantitative assessment of test performance. The panel agreed on recommending FDG-PET for 14 questions: diagnosing mild cognitive impairment due to Alzheimer's disease (AD), frontotemporal lobar degeneration (FTLD) or dementia with Lewy bodies (DLB); diagnosing atypical AD and pseudo-dementia; differentiating between AD and DLB, FTLD or vascular dementia, between DLB and FTLD, and between Parkinson's disease and progressive supranuclear palsy; suggesting underlying pathophysiology in corticobasal degeneration and progressive primary aphasia, and cortical dysfunction in Parkinson's disease; using semi-automated assessment to assist visual reading. Panellists did not support FDG-PET use for pre-clinical stages of neurodegenerative disorders, for amyotrophic lateral sclerosis and Huntington disease diagnoses, and for amyotrophic lateral sclerosis or Huntington-disease-related cognitive decline. CONCLUSIONS: Despite limited formal evidence, panellists deemed FDG-PET useful in the early and differential diagnosis of the main neurodegenerative disorders, and semi-automated assessment helpful to assist visual reading. These decisions are proposed as interim recommendations.

Consensus document on the progression and treatment response criteria in gastroenteropancreatic neuroendocrine tumors.

PURPOSE: Gastroenteropancreatic neuroendocrine tumors are a heterogeneous group of low incidence neoplasms characterized by a low proliferative activity and slow growth. Their response to targeted therapies is heterogeneous and often does not lead to tumor shrinkage. Thus, evaluation of the therapeutic response should differ from other kind of tumors. METHODS: To answer relevant questions about which techniques are best in the assessment of progression or treatment response a RAND/UCLA-based consensus process was implemented. Relevant clinical questions were listed followed by a systematic search of the literature. The expert panel answered all questions with recommendations, combining available evidence and expert opinion. Recommendations were validated through a questionnaire and a participatory meeting. RESULTS: Expert recommendations regarding imaging tools for tumor assessment and evaluation of progression were agreed upon. Available imaging techniques were reviewed and recommendations for best patient monitoring practice and the best way to evaluate treatment response were formulated.

Amyloid PET in neurodegenerative diseases with dementia. / PET amiloide en enfermedades neurodegenerativas que cursan con demencia.

Alzheimer's disease (AD) is a neurodegenerative condition characterized by progressive cognitive decline and memory loss, and is the most common form of dementia. Amyloid plaques with neurofibrillary tangles are a neuropathological hallmark of AD that produces synaptic dysfunction and culminates later in neuronal loss. Amyloid PET is a useful, available and non-invasive technique that provides in vivo information about the cortical amyloid burden. In the latest revised criteria for the diagnosis of AD biomarkers were defined and integrated: pathological and diagnostic biomarkers (increased retention on fibrillar amyloid PET or decreased Aß1-42 and increased T-Tau or P-Tau in CSF) and neurodegeneration or topographical biomarkers (temporoparietal hypometabolism on 18F-FDG PET and temporal atrophy on MRI). Recently specific recommendations have been created as a consensus statement on the appropriate use of the imaging biomarkers, including amyloid PET: early-onset cognitive impairment/dementia, atypical forms of AD, mild cognitive impairment with early age of onset, and to differentiate between AD and other neurodegenerative diseases that occur with dementia. Amyloid PET is also contributing to the development of new therapies for AD, as well as in research studies for the study of other neurodegenerative diseases that occur with dementia where the deposition of Aß amyloid is involved in its pathogenesis. In this paper, we review some general concepts and study the use of amyloid PET in depth and its relationship with neurodegenerative diseases and other diagnostic techniques.

Enfermedad de Alzheimer de inicio precoz y de inicio tardío: ¿son la misma entidad? / Early- and late-onset Alzheimer disease: Are they the same entity?

La enfermedad de Alzheimer de inicio precoz (EAIP), definida como la que se manifiesta antes de los 65 años de edad, muestra ciertas características diferentes de la enfermedad de Alzheimer de inicio tardío (EAIT). Nuestro objetivo fue analizar los trabajos más actuales que comparan la clínica, la neuropsicología, la patología, la genética y la neuroimagen de la EAIP y la EAIT, para determinar si nos enfrentamos a dos enfermedades distintas o a variantes de una misma entidad. Como resultado, hallamos consistencia en algunas características diferenciales entre los 2 cuadros clínicos. Fundamentalmente, la EAIP comienza con mayor frecuencia con una clínica atípica; la valoración cognitiva muestra mayor afectación de las funciones ejecutiva y visuoespacial y de las praxias, y menor afectación de la memoria; la neuropatología evidencia mayor densidad y una distribución más difusa de la patología tipo Alzheimer; los estudios de neuroimagen estructural y funcional muestran una afectación cortical mayor y más difusa, afectando al neocórtex (especialmente el precuneus). En conclusión, las evidencias actuales hacen pensar que la EAIP y la EAIT son variantes clínicas de una misma entidad, que en el caso de la EAIT se ve influida probablemente por factores asociados al envejecimiento

Early-onset Alzheimer disease (EOAD), which presents in patients younger than 65 years, has frequently been described as having different features from those of late-onset Alzheimer disease (LOAD). This review analyses the most recent studies comparing the clinical presentation and neuropsychological, neuropathological, genetic, and neuroimaging findings of both types in order to determine whether EOAD and LOAD are different entities or distinct forms of the same entity. We observed consistent differences between clinical findings in EOAD and in LOAD. Fundamentally, the onset of EOAD is more likely to be marked by atypical symptoms, and cognitive assessments point to poorer executive and visuospatial functioning and praxis with less marked memory impairment. Alzheimer-type features will be more dense and widespread in neuropathology studies, with structural and functional neuroimaging showing greater and more diffuse atrophy extending to neocortical areas (especially the precuneus). In conclusion, available evidence suggests that EOAD and LOAD are 2 different forms of a single entity. LOAD is likely to be influenced by ageing-related processes

Early- and late-onset Alzheimer disease: Are they the same entity? / Enfermedad de Alzheimer de inicio precoz y de inicio tardío: ¿son la misma entidad?

Early-onset Alzheimer disease (EOAD), which presents in patients younger than 65 years, has frequently been described as having different features from those of late-onset Alzheimer disease (LOAD). This review analyses the most recent studies comparing the clinical presentation and neuropsychological, neuropathological, genetic, and neuroimaging findings of both types in order to determine whether EOAD and LOAD are different entities or distinct forms of the same entity. We observed consistent differences between clinical findings in EOAD and in LOAD. Fundamentally, the onset of EOAD is more likely to be marked by atypical symptoms, and cognitive assessments point to poorer executive and visuospatial functioning and praxis with less marked memory impairment. Alzheimer-type features will be more dense and widespread in neuropathology studies, with structural and functional neuroimaging showing greater and more diffuse atrophy extending to neocortical areas (especially the precuneus). In conclusion, available evidence suggests that EOAD and LOAD are 2 different forms of a single entity. LOAD is likely to be influenced by ageing-related processes.

Nuevos tiempos para la neuroimagen de Medicina Nuclear en España: ¿de dónde partimos? / A new era for Nuclear Medicine neuroimaging in Spain: Where do we start from in Spain?

Objetivo. conocer la situación de los estudios de neuroimagen de Medicina Nuclear que se realizaron en España en el año 2013 y primer trimestre del 2014, con el fin de definir las actividades del grupo de trabajo de Neuroimagen de la Sociedad Española de Medicina Nuclear e Imagen Molecular (SEMNIM). Material y métodos. Se diseñó un cuestionario de 14 preguntas dividido en 3 partes: características de los servicios (equipamiento y profesionales involucrados), tipo de exploraciones e indicaciones clínicas y métodos de evaluación. El cuestionario se remitió a los 166 servicios de Medicina Nuclear que figuraban en la secretaría de la Sociedad Española de Medicina Nuclear e Imagen Molecular. Resultados. Respondieron a la encuesta un total de 54 centros distribuidos entre todas las comunidades autónomas. La mayoría de los centros realizaron entre 300 y 800 exploraciones de neuroimagen al año, representando más de 25 exploraciones al mes. La media de equipos por servicio era de 3, teniendo la mitad de ellos equipos PET/TC y SPECT/TC. Las exploraciones realizadas con más frecuencia son la SPECT cerebral con 123I-FP-CIT, seguida de la SPECT cerebral de perfusión y de la PET con 18F-FDG, siendo las indicaciones clínicas más frecuentes los estudios de deterioro cognitivo seguidos por los de trastornos del movimiento. Para la evaluación de las pruebas la mayoría de los centros utilizaron únicamente la valoración visual, en la valoración cuantitativa la cuantificación por regiones de interés fue la más utilizada. Conclusiones. Los resultados reflejan cuál fue la actividad clínica del año 2013 y primer trimestre del 2014, siendo las indicaciones principales los estudios de deterioro cognitivo y trastorno del movimiento. La variabilidad en la evaluación de los estudios PET y la colaboración con los especialistas clínicos que demandan las exploraciones de neuroimagen de Medicina Nuclear son algunos de los retos que debemos afrontar en los próximos años (AU)

Objective. To determine the status of neuroimaging studies of Nuclear Medicine in Spain during 2013 and first quarter of 2014, in order to define the activities of the neuroimaging group of the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM). Material and methods. A questionnaire of 14 questions was designed, divided into 3 parts: characteristics of the departments (equipment and professionals involved); type of scans and clinical indications; and evaluation methods. The questionnaire was sent to 166 Nuclear Medicine departments. Results. A total of 54 departments distributed among all regions completed the questionnaire. Most departments performed between 300 and 800 neuroimaging examinations per year, representing more than 25 scans per month. The average pieces of equipment were three; half of the departments had a PET/CT scanner and SPECT/CT equipment. Scans performed more frequently were brain SPECT with 123I-FP-CIT, followed by brain perfusion SPECT and PET with 18F-FDG. The most frequent clinical indications were cognitive impairment followed by movement disorders. For evaluation of the images most sites used only visual assessment, and for the quantitative assessment the most used was quantification by region of interest. Conclusions. These results reflect the clinical activity of 2013 and first quarter of 2014. The main indications of the studies were cognitive impairment and movement disorders. Variability in the evaluation of the studies is among the challenges that will be faced in the coming years (AU)

Biomarcadores por tomografia por emisión de positrones (PET): imagen de la patología de Alzheimer y la neurodegeneración al servicio del diagnóstico clínico / PET biomarkers: Use of imaging techniques in Alzheimer disease and neurodegeneration clinical diagnosis

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A new era for Nuclear Medicine neuroimaging in Spain: Where do we start from in Spain? / Nuevos tiempos para la neuroimagen de Medicina Nuclear en España: ¿de dónde partimos?

OBJECTIVE: To determine the status of neuroimaging studies of Nuclear Medicine in Spain during 2013 and first quarter of 2014, in order to define the activities of the neuroimaging group of the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM). MATERIAL AND METHODS: A questionnaire of 14 questions was designed, divided into 3 parts: characteristics of the departments (equipment and professionals involved); type of scans and clinical indications; and evaluation methods. The questionnaire was sent to 166 Nuclear Medicine departments. RESULTS: A total of 54 departments distributed among all regions completed the questionnaire. Most departments performed between 300 and 800 neuroimaging examinations per year, representing more than 25 scans per month. The average pieces of equipment were three; half of the departments had a PET/CT scanner and SPECT/CT equipment. Scans performed more frequently were brain SPECT with 123I-FP-CIT, followed by brain perfusion SPECT and PET with 18F-FDG. The most frequent clinical indications were cognitive impairment followed by movement disorders. For evaluation of the images most sites used only visual assessment, and for the quantitative assessment the most used was quantification by region of interest. CONCLUSIONS: These results reflect the clinical activity of 2013 and first quarter of 2014. The main indications of the studies were cognitive impairment and movement disorders. Variability in the evaluation of the studies is among the challenges that will be faced in the coming years.

Recomendaciones para la utilización de biomarcadores de imagen PET en el proceso diagnóstico de las enfermedades neurodegenerativas que cursan con demencia: documento de consenso SEMNIM y SEN / Recommendations for the use of PET imaging biomarkers in the diagnosis of neurodegenerative conditions associated with dementia: SEMNIM and SEN consensus

Los nuevos criterios diagnósticos para la enfermedad de Alzheimer (EA) reconocen el interés de los biomarcadores, tanto para mejorar la especificidad en sujetos en fase de demencia, como para facilitar el diagnóstico precoz del proceso fisiopatológico de la EA en personas en fases prodrómicas. La disponibilidad actual de biomarcadores de imagen PET de disfunción neuronal (PET-FDG) y de depósito de proteína beta amiloide (PET-Amiloide), ofrecen a los especialistas clínicos involucrados en la evaluación de pacientes con deterioro cognitivo la oportunidad de aplicar los nuevos criterios en su práctica clínica. Sin embargo, resulta imprescindible que las sociedades científicas implicadas en la utilización de las nuevas herramientas de apoyo al diagnóstico clínico se pongan de acuerdo en cuales deben de ser las recomendaciones para su utilización clínica. En este trabajo se lleva a cabo una revisión sistemática de la literatura sobre el uso de PET-amiloide y PET-FDG, tanto en el proceso diagnóstico de la EA como de otras enfermedades neurodegenerativas que cursan con demencia. Asimismo, se proponen una serie de recomendaciones consensuadas por la Sociedad Española de Medicina Nuclear y la Sociedad Española de Neurología a modo guía para la utilización adecuada de los biomarcadores de imagen PET (AU)

The new diagnostic criteria for Alzheimer's disease (AD) acknowledges the interest given to biomarkers to improve the specificity in subjects with dementia and to facilitate an early diagnosis of the pathophysiological process of AD in the prodromal or pre-dementia stage. The current availability of PET imaging biomarkers of synaptic dysfunction (PET-FDG) and beta amyloid deposition using amyloid-PET provides clinicians with the opportunity to apply the new criteria and improve diagnostic accuracy in their clinical practice. Therefore, it seems essential for the scientific societies involved to use the new clinical diagnostic support tools to establish clear, evidence-based and agreed set of recommendations for their appropriate use. The present work includes a systematic review of the literature on the utility of FDG-PET and amyloid-PET for the diagnosis of AD and related neurodegenerative diseases that occur with dementia. Thus, we propose a series of recommendations agreed on by the Spanish Society of Nuclear Medicine and Spanish Society of Neurology as a consensus statement on the appropriate use of PET imaging biomarkers (AU)

Descripción de una serie de pacientes con diagnóstico de enfermedad priónica / Clinical and neuroimaging characteristics of 14 patients with prionopathy: A descriptive study

Introducción: Las prionopatías representan hasta el 62% de los casos de demencia rápidamente progresiva (DRP) en los que se alcanza un diagnóstico definitivo. La variabilidad de los síntomas y signos iniciales y las diferencias en su evolución dificultan el diagnóstico precoz. Métodos: Estudio retrospectivo en el que se incluye a pacientes con prionopatía probable o definitiva, que acudieron a la consulta de Neurología de nuestro centro durante el periodo 1999-2012. Se describen las características clínicas y los resultados de las exploraciones complementarias (proteína 14-3-3, EEG, RM, PET-FDG y análisis genético), con la finalidad de identificar qué marcadores permiten un diagnóstico precoz. Resultados: Se describe a 14 pacientes: 6 con enfermedad de Creutzfeldt-Jakob esporádica (ECJe) definitiva, 3 con ECJe probable, 4 con insomnio familiar fatal y uno con la nueva variante de la enfermedad de Creutzfeldt-Jakob. La mediana de edad al diagnóstico fue de 54 años y la mediana de supervivencia de 9,5 meses. El trastorno del ánimo fue el síntoma inicial más frecuente, seguido de inestabilidad de la marcha y deterioro cognitivo. La proteína 14-3-3 fue positiva en el líquido cefalorraquídeo en 7 de 11 pacientes y el EEG mostró signos típicos en 2 de 12 pacientes explorados. El estudio de neuroimagen mostró alteraciones en 13 de los 14 pacientes. Conclusiones: Además de la DRP, el trastorno conductual y de la marcha son síntomas iniciales frecuentes en las prionopatías. En nuestra serie, las pruebas complementarias más útiles para apoyar el diagnóstico fueron la RM y la PET-FDG

Introduction: Prionopathy is the cause of 62% of the rapidly progressive dementias (RPD) in which a definitive diagnosis is reached. The variability of symptoms and signs exhibited by the patients, as well as its different presentation, sometimes makes an early diagnosis difficult. Methods: Patients withdiagnosis of definite or probable prionopathy during the period 1999-2012 at our hospital were retrospectively reviewed.The clinical features and the results of the complementary tests (14-3-3 protein, EEG, MRI, FDG-PET, and genetic analysis) were evaluated in order to identify some factors that may enable an earlier diagnosis to be made. Results: A total of 14 patients are described: 6 with definite sporadic Creutzfeldt-Jakob (sCJD) disease, 3 with probable sCJD, 4 with fatal familial insomnia, and 1 with the new variant. The median age at diagnosis was 54 years old. The mean survival was 9.5 months. Mood disorder was the most common feature, followed by instability and cognitive impairment. 14-3-3 protein content in the cerebrospinal fluid was positive in 7 of 11 patients, and the EEG showed typical signs in 2 of 12 patients. Neuroimaging (FDG-PET, MRI) studies suggested the diagnosis in 13 of the 14 patients included. Conclusions: Most patients presenting with RPD suffer from a prion disease. In our series the most useful complementary tests were MRI and FDG-PET, being positive in 13 of the 14 patients studied

Clinical and neuroimaging characteristics of 14 patients with prionopathy: a descriptive study.

INTRODUCTION: Prionopathy is the cause of 62% of the rapidly progressive dementias (RPD) in which a definitive diagnosis is reached. The variability of symptoms and signs exhibited by the patients, as well as its different presentation, sometimes makes an early diagnosis difficult. METHODS: Patients withdiagnosis of definite or probable prionopathy during the period 1999-2012 at our hospital were retrospectively reviewed.The clinical features and the results of the complementary tests (14-3-3 protein, EEG, MRI, FDG-PET, and genetic analysis) were evaluated in order to identify some factors that may enable an earlier diagnosis to be made. RESULTS: A total of 14 patients are described: 6 with definite sporadic Creutzfeldt-Jakob (sCJD) disease, 3 with probable sCJD, 4 with fatal familial insomnia, and 1 with the new variant. The median age at diagnosis was 54 years old. The mean survival was 9.5 months. Mood disorder was the most common feature, followed by instability and cognitive impairment. 14-3-3 protein content in the cerebrospinal fluid was positive in 7 of 11 patients, and the EEG showed typical signs in 2 of 12 patients. Neuroimaging (FDG-PET, MRI) studies suggested the diagnosis in 13 of the 14 patients included. CONCLUSIONS: Most patients presenting with RPD suffer from a prion disease. In our series the most useful complementary tests were MRI and FDG-PET, being positive in 13 of the 14 patients studied.

Neuroimagen funcional en el diagnóstico de pacientes con síndrome parkinsoniano: actualización y recomendaciones para el uso clínico / Functional neuroimaging in the diagnosis of patients with Parkinsonism: Update and recommendations for clinical use

Las técnicas de neuroimagen funcional se han utilizado tradicionalmente en la investigación de los pacientes que presentan un síndrome parkinsoniano. Sin embargo, la aparición de radiofármacos comerciales junto a la disponibilidad de equipos de tomografía por emisión de fotón único (SPECT) y más recientemente de la tomografía por emisión de positrones (PET), han permitido su empleo rutinario en la práctica clínica. Precisamente el desarrollo y grado de evidencia clínica alcanzado por los biomarcadores de neuroimagen durante las 2 últimas décadas ha conllevado que progresivamente se estén incluyendo en los criterios clínicos de diagnóstico de enfermedades neurodegenerativas que cursan con un síndrome parkinsoniano. No obstante, la diversidad de radiofármacos que permiten evaluar la funcionalidad de las vías anatómicas involucradas en la neurodegeneración presente en los diferentes síndromes parkinsonianos (vía nigroestriatal dopaminérgica, actividad neuronal de los ganglios basales y la corteza, inervación simpática miocárdica), junto a las técnicas de neuroimagen (gammagrafía, SPECT y PET) han originado cierta controversia con respecto a la indicación de las pruebas de neuroimagen como exploración complementaria. En esta revisión realizada por un panel de expertos en medicina nuclear y neurología se analizan las técnicas de neuroimagen funcional disponibles haciendo especial énfasis en las consideraciones prácticas del diagnóstico de pacientes con un síndrome parkinsoniano de origen incierto y la valoración de la progresión de la enfermedad de Parkinson (AU)

Functional Neuroimaging has been traditionally used in research for patients with different Parkinsonian syndromes. However, the emergence of commercial radiotracers together with the availability of single photon emission computed tomography (SPECT) and, more recently, positron emission tomography (PET) have made them available for clinical practice. Particularly, the development of clinical evidence achieved by functional neuroimaging techniques over the past two decades have motivated a progressive inclusion of several biomarkers in the clinical diagnostic criteria for neurodegenerative diseases that occur with Parkinsonism. However, the wide range of radiotracers designed to assess the involvement of different pathways in the neurodegenerative process underlying Parkinsonian syndromes (dopaminergic nigrostriatal pathway integrity, basal ganglia and cortical neuronal activity, myocardial sympathetic innervation), and the different neuroimaging techniques currently available (scintigraphy, SPECT and PET), have generated some controversy concerning the best neuroimaging test that should be indicated for the differential diagnosis of Parkinsonism. In this article, a panel of nuclear medicine and neurology experts has evaluated the functional neuroimaging techniques emphazising practical considerations related to the diagnosis of patients with uncertain origin parkinsonism and the assessment Parkinson’s disease progression (AU)