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1.
Acta Neurochir (Wien) ; 158(12): 2311-2319, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27743250

RESUMEN

OBJECTIVES: Optimal selection of idiopathic normal pressure hydrocephalus (iNPH) patients for shunt surgery is challenging. Disease State Index (DSI) is a statistical method that merges multimodal data to assist clinical decision-making. It has previously been shown to be useful in predicting progression in mild cognitive impairment and differentiating Alzheimer's disease (AD) and frontotemporal dementia. In this study, we use the DSI method to predict shunt surgery response for patients with iNPH. METHODS: In this retrospective cohort study, a total of 284 patients (230 shunt responders and 54 non-responders) from the Kuopio NPH registry were analyzed with the DSI. Analysis included data from patients' memory disorder assessments, age, clinical symptoms, comorbidities, medications, frontal cortical biopsy, CT/MRI imaging (visual scoring of disproportion between Sylvian and suprasylvian subarachnoid spaces, atrophy of medial temporal lobe, superior medial subarachnoid spaces), APOE genotyping, CSF AD biomarkers, and intracranial pressure. RESULTS: Our analysis showed that shunt responders cannot be differentiated from non-responders reliably even with the large dataset available (AUC = 0.58). CONCLUSIONS: Prediction of the treatment response in iNPH is challenging even with our extensive dataset and refined analysis. Further research of biomarkers and indicators predicting shunt responsiveness is still needed.


Asunto(s)
Derivaciones del Líquido Cefalorraquídeo/efectos adversos , Hidrocéfalo Normotenso/patología , Procedimientos Neuroquirúrgicos/efectos adversos , Anciano , Biomarcadores/metabolismo , Derivaciones del Líquido Cefalorraquídeo/métodos , Toma de Decisiones Clínicas , Femenino , Humanos , Hidrocéfalo Normotenso/diagnóstico por imagen , Hidrocéfalo Normotenso/cirugía , Presión Intracraneal , Imagen por Resonancia Magnética , Masculino , Memoria , Persona de Mediana Edad , Procedimientos Neuroquirúrgicos/métodos , Selección de Paciente , Estudios Retrospectivos
2.
Neurodegener Dis ; 13(2-3): 200-2, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-23969422

RESUMEN

BACKGROUND: The Disease State Index (DSI) is a method which interprets data originating from multiple different sources, assisting the clinician in the diagnosis and follow-up of dementia diseases. OBJECTIVE: We compared the differences in accuracy in differentiating stable mild cognitive impairment (S-MCI) and progressive MCI (P-MCI) obtained from different data combinations using the DSI. METHODS: We investigated 212 cases with S-MCI and 165 cases with P-MCI from the Alzheimer's Disease Neuroimaging Initiative cohort. Data from neuropsychological tests, cerebrospinal fluid, apolipoprotein E (APOE) genotype, magnetic resonance imaging (MRI) and positron emission tomography (PET) were included. RESULTS: The combination of all parameters gave the highest accuracy (accuracy 0.70, sensitivity 0.71, specificity 0.68). In the different categories, neuropsychological tests (0.65, 0.65, 0.65) and hippocampal volumetry (0.66, 0.66, 0.66) achieved the highest accuracy. CONCLUSION: In addition to neuropsychological testing, MRI is recommended to be included for differentiating S-MCI from P-MCI. APOE genotype, CSF and PET may provide some additional information.


Asunto(s)
Enfermedad de Alzheimer , Biomarcadores/análisis , Disfunción Cognitiva , Progresión de la Enfermedad , Anciano , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Pruebas Neuropsicológicas , Tomografía de Emisión de Positrones , Sensibilidad y Especificidad
3.
Dement Geriatr Cogn Disord ; 34(5-6): 344-50, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23222123

RESUMEN

BACKGROUND: The PredictAD tool integrates heterogeneous data such as imaging, cerebrospinal fluid biomarkers and results from neuropsychological tests for compact visualization in an interactive user interface. This study investigated whether the software tool could assist physicians in the early diagnosis of Alzheimer's disease. METHODS: Baseline data from 140 patients with mild cognitive impairment were selected from the Alzheimer's Disease Neuroimaging Study. Three clinical raters classified patients into 6 categories of confidence in the prediction of early Alzheimer's disease, in 4 phases of incremental data presentation using the software tool. A 5th phase was done with all available patient data presented on paper charts. Classifications by the clinical raters were compared to the clinical diagnoses made by the Alzheimer's Disease Neuroimaging Initiative investigators. RESULTS: A statistical significant trend (p < 0.05) towards better classification accuracy (from 62.6 to 70.0%) was found when using the PredictAD tool during the stepwise procedure. When the same data were presented on paper, classification accuracy of the raters dropped significantly from 70.0 to 63.2%. CONCLUSION: Best classification accuracy was achieved by the clinical raters when using the tool for decision support, suggesting that the tool can add value in diagnostic classification when large amounts of heterogeneous data are presented.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/psicología , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/psicología , Pruebas Neuropsicológicas , Programas Informáticos , Factores de Edad , Anciano , Enfermedad de Alzheimer/clasificación , Disfunción Cognitiva/clasificación , Progresión de la Enfermedad , Escolaridad , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Neuroimagen , Variaciones Dependientes del Observador , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Factores Socioeconómicos
4.
Adv Exp Med Biol ; 736: 95-118, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22161324

RESUMEN

We have developed a system called megNet for integrating and visualizing heterogeneous biological data in order to enable modeling biological phenomena using a systems approach. Herein we describe megNet, including a recently developed user interface for visualizing biological networks in three dimensions and a web user interface for taking input parameters from the user, and an in-house text mining system that utilizes an existing knowledge base. We demonstrate the software with a case study in which we integrate lipidomics data acquired in-house with interaction data from external databases, and then find novel interactions that could possibly explain our previous associations between biological data and medical images. The flexibility of megNet assures that the tool can be applied in diverse applications, from target discovery in medical applications to metabolic engineering in industrial biotechnology.


Asunto(s)
Modelos Biológicos , Transducción de Señal/fisiología , Programas Informáticos , Biología de Sistemas/métodos , Animales , Bases de Datos Factuales , Perfilación de la Expresión Génica/métodos , Genómica/métodos , Humanos , Almacenamiento y Recuperación de la Información/métodos , Lamina Tipo A/genética , Lamina Tipo A/metabolismo , Metabolismo de los Lípidos , Redes y Vías Metabólicas/genética , Redes y Vías Metabólicas/fisiología , Unión Proteica , Transducción de Señal/genética , Interfaz Usuario-Computador
5.
Neurodegener Dis ; 10(1-4): 149-52, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22156511

RESUMEN

BACKGROUND: Diagnostic criteria of Alzheimer's disease (AD) emphasize the integration of clinical data and biomarkers. In practice, collection and analysis of patient data vary greatly across different countries and clinics. OBJECTIVE: The goal was to develop a versatile and objective clinical decision support system that could reduce diagnostic errors and highlight early predictors of AD. METHODS: Novel data analysis methods were developed to derive composite disease indicators from heterogeneous patient data. Visualizations that communicate these findings were designed to help the interpretation. The methods were implemented with a software tool that is aimed for daily clinical practice. RESULTS: With the tool, clinicians can analyze available patients as a whole, study them statistically against previously diagnosed cases, and characterize the patients with respect to having AD. The tool is able to work with virtually any patient measurement data, as long as they are stored in electronic format or manually entered into the system. For a subset of patients from the test cohort, the tool was able to predict conversion to AD at an accuracy of 93.6%. CONCLUSION: The software tool developed in this study provides objective information for early detection and prediction of AD based on interpretable visualizations of patient data.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Disfunción Cognitiva/diagnóstico , Programas Informáticos , Anciano , Enfermedad de Alzheimer/etiología , Disfunción Cognitiva/complicaciones , Sistemas de Apoyo a Decisiones Clínicas , Progresión de la Enfermedad , Femenino , Humanos , Estudios Longitudinales , Masculino , Escalas de Valoración Psiquiátrica
6.
J Alzheimers Dis ; 76(3): 1061-1070, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32597806

RESUMEN

BACKGROUND: Gait analysis with accelerometers is a relatively inexpensive and easy to use method to potentially support clinical diagnoses of Alzheimer's disease and other dementias. It is not clear, however, which gait features are most informative and how these measures relate to Alzheimer's disease pathology. OBJECTIVE: In this study, we tested if calculated features of gait 1) differ between cognitively normal subjects (CN), mild cognitive impairment (MCI) patients, and dementia patients, 2) are correlated with cerebrospinal fluid (CSF) biomarkers related to Alzheimer's disease, and 3) predict cognitive decline. METHODS: Gait was measured using tri-axial accelerometers attached to the fifth lumbar vertebra (L5) in 58 CN, 58 MCI, and 26 dementia participants, while performing a walk and dual task. Ten gait features were calculated from the vertical L5 accelerations, following principal component analysis clustered in four domains, namely pace, rhythm, time variability, and length variability. Cognitive decline over time was measured using MMSE, and CSF biomarkers were available in a sub-group. RESULTS: Linear mixed models showed that dementia patients had lower pace scores than MCI patients and CN subjects (p < 0.05). In addition, we found associations between the rhythm domain and CSF-tau, especially in the dual task. Gait was not associated with CSF Aß42 levels and cognitive decline over time as measured with the MMSE. CONCLUSION: These findings suggest that gait - particularly measures related to pace and rhythm - are altered in dementia and have a direct link with measures of neurodegeneration.


Asunto(s)
Péptidos beta-Amiloides/líquido cefalorraquídeo , Cognición/fisiología , Disfunción Cognitiva/fisiopatología , Trastornos Neurológicos de la Marcha/etiología , Marcha/fisiología , Proteínas tau/líquido cefalorraquídeo , Anciano , Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/patología , Biomarcadores/líquido cefalorraquídeo , Disfunción Cognitiva/líquido cefalorraquídeo , Disfunción Cognitiva/complicaciones , Disfunción Cognitiva/diagnóstico , Estudios de Cohortes , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Memoria/fisiología , Persona de Mediana Edad , Pruebas Neuropsicológicas , Fragmentos de Péptidos/líquido cefalorraquídeo
7.
IEEE J Biomed Health Inform ; 23(3): 1261-1268, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-29993563

RESUMEN

Traumatic brain injury (TBI) occurs when an external force causes functional or structural alterations in the brain. Clinical characteristics of TBI vary greatly from patient to patient, and a large amount of data is gathered during various phases of clinical care in these patients. It is hard for clinicians to efficiently integrate and interpret all of these data and plan interventions in a timely manner. This paper describes the technical architecture and functionality of a web-based decision support system (DSS), which not only provides advanced support for visualizing complex TBI data but also predicts a possible outcome by using a state-of-the-art Disease State Index machine-learning algorithm. The DSS is developed by using a three-layered architecture and by employing modern programming principles, software design patterns, and using robust technologies (C#, ASP.NET MVC, HTML5, JavaScript, Entity Framework, etc.). The DSS is comprised of a patient overview module, a disease-state prediction module, and an imaging module. After deploying it on a web-server, the DSS was made available to two hospitals in U.K. and Finland. Afterwards, we conducted a validation study to evaluate its usability in clinical settings. Initial results of the study indicate that especially less experience clinicians may benefit from this type of decision support software tool.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Sistemas de Apoyo a Decisiones Clínicas , Programas Informáticos , Lesiones Traumáticas del Encéfalo/diagnóstico , Lesiones Traumáticas del Encéfalo/terapia , Humanos , Internet
8.
Alzheimers Res Ther ; 11(1): 11, 2019 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-30670070

RESUMEN

BACKGROUND: We developed multifactorial models for predicting incident dementia and brain pathology in the oldest old using the Vantaa 85+ cohort. METHODS: We included participants without dementia at baseline and at least 2 years of follow-up (N = 245) for dementia prediction or with autopsy data (N = 163) for pathology. A supervised machine learning method was used for model development, considering sociodemographic, cognitive, clinical, vascular, and lifestyle factors, as well as APOE genotype. Neuropathological assessments included ß-amyloid, neurofibrillary tangles and neuritic plaques, cerebral amyloid angiopathy (CAA), macro- and microscopic infarcts, α-synuclein pathology, hippocampal sclerosis, and TDP-43. RESULTS: Prediction model performance was evaluated using AUC for 10 × 10-fold cross-validation. Overall AUCs were 0.73 for dementia, 0.64-0.68 for Alzheimer's disease (AD)- or amyloid-related pathologies, 0.72 for macroinfarcts, and 0.61 for microinfarcts. Predictors for dementia were different from those in previous reports of younger populations; for example, age, sex, and vascular and lifestyle factors were not predictive. Predictors for dementia versus pathology were also different, because cognition and education predicted dementia but not AD- or amyloid-related pathologies. APOE genotype was most consistently present across all models. APOE alleles had a different impact: ε4 did not predict dementia, but it did predict all AD- or amyloid-related pathologies; ε2 predicted dementia, but it was protective against amyloid and neuropathological AD; and ε3ε3 was protective against dementia, neurofibrillary tangles, and CAA. Very few other factors were predictive of pathology. CONCLUSIONS: Differences between predictors for dementia in younger old versus oldest old populations, as well as for dementia versus pathology, should be considered more carefully in future studies.


Asunto(s)
Apolipoproteína E4/genética , Encéfalo/patología , Demencia/diagnóstico , Demencia/genética , Pruebas de Estado Mental y Demencia , Anciano de 80 o más Años , Causalidad , Estudios de Cohortes , Demencia/epidemiología , Femenino , Finlandia/epidemiología , Estudios de Seguimiento , Humanos , Masculino , Valor Predictivo de las Pruebas
9.
J Alzheimers Dis ; 71(4): 1233-1243, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31498122

RESUMEN

BACKGROUND: Idiopathic normal pressure hydrocephalus (iNPH) patients often develop Alzheimer's disease (AD) related brain pathology. Disease State Index (DSI) is a method to combine data from various sources for differential diagnosis and progression of neurodegenerative disorders. OBJECTIVE: To apply DSI to predict clinical AD in shunted iNPH-patients in a defined population. METHODS: 335 shunted iNPH-patients (median 74 years) were followed until death (n = 185) or 6/2015 (n = 150). DSI model (including symptom profile, onset age of NPH symptoms, atrophy of medial temporal lobe in CT/MRI, cortical brain biopsy finding, and APOE genotype) was applied. Performance of DSI model was evaluated with receiver operating characteristic (ROC) curve analysis. RESULTS: A total of 70 (21%) patients developed clinical AD during median follow-up of 5.3 years. DSI-model predicted clinical AD with moderate effectiveness (AUC = 0.75). Significant factors were cortical biopsy (0.69), clinical symptoms (0.66), and medial temporal lobe atrophy (0.66). CONCLUSION: We found increased occurrence of clinical AD in previously shunted iNPH patients as compared with general population. DSI supported the prediction of AD. Cortical biopsy during shunt insertion seems indicated for earlier diagnosis of comorbid AD.


Asunto(s)
Enfermedad de Alzheimer , Corteza Cerebral/patología , Derivaciones del Líquido Cefalorraquídeo , Hidrocéfalo Normotenso , Lóbulo Temporal/diagnóstico por imagen , Edad de Inicio , Anciano , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/epidemiología , Biopsia/métodos , Derivaciones del Líquido Cefalorraquídeo/métodos , Derivaciones del Líquido Cefalorraquídeo/estadística & datos numéricos , Comorbilidad , Diagnóstico Precoz , Femenino , Humanos , Hidrocéfalo Normotenso/diagnóstico , Hidrocéfalo Normotenso/epidemiología , Hidrocéfalo Normotenso/psicología , Hidrocéfalo Normotenso/cirugía , Imagen por Resonancia Magnética/métodos , Masculino , Pronóstico
10.
J Alzheimers Dis ; 55(3): 1055-1067, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27802228

RESUMEN

BACKGROUND AND OBJECTIVE: This study aimed to develop a late-life dementia prediction model using a novel validated supervised machine learning method, the Disease State Index (DSI), in the Finnish population-based CAIDE study. METHODS: The CAIDE study was based on previous population-based midlife surveys. CAIDE participants were re-examined twice in late-life, and the first late-life re-examination was used as baseline for the present study. The main study population included 709 cognitively normal subjects at first re-examination who returned to the second re-examination up to 10 years later (incident dementia n = 39). An extended population (n = 1009, incident dementia 151) included non-participants/non-survivors (national registers data). DSI was used to develop a dementia index based on first re-examination assessments. Performance in predicting dementia was assessed as area under the ROC curve (AUC). RESULTS: AUCs for DSI were 0.79 and 0.75 for main and extended populations. Included predictors were cognition, vascular factors, age, subjective memory complaints, and APOE genotype. CONCLUSION: The supervised machine learning method performed well in identifying comprehensive profiles for predicting dementia development up to 10 years later. DSI could thus be useful for identifying individuals who are most at risk and may benefit from dementia prevention interventions.


Asunto(s)
Demencia/diagnóstico , Demencia/epidemiología , Índice de Severidad de la Enfermedad , Aprendizaje Automático Supervisado , Anciano , Apolipoproteínas E/genética , Trastornos Cerebrovasculares/epidemiología , Cognición/fisiología , Planificación en Salud Comunitaria , Demencia/genética , Femenino , Finlandia/epidemiología , Humanos , Masculino , Pruebas Neuropsicológicas , Valor Predictivo de las Pruebas , Curva ROC , Reproducibilidad de los Resultados , Estudios Retrospectivos , Factores de Riesgo
11.
Stud Health Technol Inform ; 224: 175-80, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27225575

RESUMEN

Traumatic brain injury (TBI) is a major cause of death and disability, especially in young adults. A reliable prediction of outcome after TBI is of great importance in clinical practice and research. We aimed to compare performance of the well-established IMPACT calculator and an alternative method, Disease State Index (DSI), in the prediction of six-month outcome after TBI. Performance of the models was evaluated using 2036 patients with moderate or severe TBI from the International Mission for Prognosis and Analysis of Clinical Trials in TBI (IMPACT) database. Prediction performance of both models was similar. The models with more variables provided better performance than the simpler models. This study showed that the DSI is a valid tool with efficient visualizations that can help clinicians with their decision making process in clinical practice.


Asunto(s)
Lesiones Traumáticas del Encéfalo/diagnóstico , Diagnóstico por Computador/métodos , Evaluación del Resultado de la Atención al Paciente , Valor Predictivo de las Pruebas , Adulto , Lesiones Traumáticas del Encéfalo/mortalidad , Diagnóstico por Computador/estadística & datos numéricos , Femenino , Escala de Consecuencias de Glasgow , Humanos , Masculino , Pronóstico , Índice de Severidad de la Enfermedad
12.
J Alzheimers Dis ; 50(1): 261-70, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26577521

RESUMEN

BACKGROUND: Recent criteria allow biomarkers to provide evidence of Alzheimer's disease (AD) pathophysiology. How they should be implemented in daily practice remains unclear, especially in mild cognitive impairment (MCI) patients. OBJECTIVE: We evaluated how a clinical decision support system such as the PredictAD tool can aid clinicians to integrate biomarker evidence to support AD diagnosis. METHODS: With available data on demographics, cerebrospinal fluid (CSF), and MRI, we trained the PredictAD tool on a reference population of 246 controls and 491 AD patients. We then applied the identified algorithm to 211 MCI patients. For comparison, we also classified patients based on individual biomarkers (MRI; CSF) and the NIA-AA criteria. Progression to dementia was used as outcome measure. RESULTS: After a median follow up of 3 years, 72 (34%) MCI patients remained stable and 139 (66%) progressed to AD. The PredictAD tool assigned a likelihood of underlying AD to each patient (AUC 0.82). Excluding patients with missing data resulted in an AUC of 0.87. According to the NIA-AA criteria, half of the MCI patients had uninformative biomarkers, precluding an assignment of AD likelihood. A minority (41%) was assigned to high or low AD likelihood with good predictive value. The individual biomarkers showed best value for CSF total tau (AUC 0.86). CONCLUSION: The ability of the PredictAD tool to identify AD pathophysiology was comparable to individual biomarkers. The PredictAD tool has the advantage that it assigns likelihood to all patients, regardless of missing or conflicting data, allowing clinicians to integrate biomarker data in daily practice.


Asunto(s)
Enfermedad de Alzheimer/líquido cefalorraquídeo , Enfermedad de Alzheimer/patología , Biomarcadores/líquido cefalorraquídeo , Disfunción Cognitiva/líquido cefalorraquídeo , Disfunción Cognitiva/patología , Sistemas de Apoyo a Decisiones Clínicas , Anciano , Anciano de 80 o más Años , Algoritmos , Área Bajo la Curva , Estudios de Cohortes , Progresión de la Enfermedad , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Escala del Estado Mental , Persona de Mediana Edad , Pruebas Neuropsicológicas , Evaluación de Resultado en la Atención de Salud , Valor Predictivo de las Pruebas
13.
Dement Geriatr Cogn Dis Extra ; 6(2): 313-329, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27703465

RESUMEN

BACKGROUND: Disease State Index (DSI) and its visualization, Disease State Fingerprint (DSF), form a computer-assisted clinical decision making tool that combines patient data and compares them with cases with known outcomes. AIMS: To investigate the ability of the DSI to diagnose frontotemporal dementia (FTD) and Alzheimer's disease (AD). METHODS: The study cohort consisted of 38 patients with FTD, 57 with AD and 22 controls. Autopsy verification of FTD with TDP-43 positive pathology was available for 14 and AD pathology for 12 cases. We utilized data from neuropsychological tests, volumetric magnetic resonance imaging, single-photon emission tomography, cerebrospinal fluid biomarkers and the APOE genotype. The DSI classification results were calculated with a combination of leave-one-out cross-validation and bootstrapping. A DSF visualization of a FTD patient is presented as an example. RESULTS: The DSI distinguishes controls from FTD (area under the receiver-operator curve, AUC = 0.99) and AD (AUC = 1.00) very well and achieves a good differential diagnosis between AD and FTD (AUC = 0.89). In subsamples of autopsy-confirmed cases (AUC = 0.97) and clinically diagnosed cases (AUC = 0.94), differential diagnosis of AD and FTD performs very well. CONCLUSIONS: DSI is a promising computer-assisted biomarker approach for aiding in the diagnostic process of dementing diseases. Here, DSI separates controls from dementia and differentiates between AD and FTD.

14.
J Alzheimers Dis ; 44(1): 79-92, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25201784

RESUMEN

BACKGROUND: The Disease State Index (DSI) prediction model measures the similarity of patient data to diagnosed stable and progressive mild cognitive impairment (MCI) cases to identify patients who are progressing to Alzheimer's disease. OBJECTIVES: We evaluated how well the DSI generalizes across four different cohorts: DESCRIPA, ADNI, AddNeuroMed, and the Kuopio MCI study. METHODS: The accuracy of the DSI in predicting progression was examined for each cohort separately using 10 × 10-fold cross-validation and for inter-cohort validation using each cohort as a test set for the model built from the other independent cohorts using bootstrapping with 10 repetitions. Altogether 875 subjects were included in the analysis. The analyzed data included a comprehensive set of age and gender corrected magnetic resonance imaging (MRI) features from hippocampal volumetry, multi-template tensor-based morphometry, and voxel-based morphometry as well as Mini-Mental State Examination (MMSE), APOE genotype, and additional cohort specific data from neuropsychological tests and cerebrospinal fluid measurements (CSF). RESULTS: The DSI model was used to classify the patients into stable and progressive MCI cases. AddNeuroMed had the highest classification results of the cohorts, while ADNI and Kuopio MCI exhibited the lowest values. The MRI features alone achieved a good classification performance for all cohorts. For ADNI and DESCRIPA, adding MMSE, APOE genotype, CSF, and neuropsychological data improved the results. CONCLUSIONS: The results reveal that the prediction performance of the combined cohort is close to the average of the individual cohorts. It is feasible to use different cohorts as training sets for the DSI, if they are sufficiently similar.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/fisiopatología , Disfunción Cognitiva/fisiopatología , Progresión de la Enfermedad , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/genética , Apolipoproteínas E/genética , Área Bajo la Curva , Encéfalo/patología , Disfunción Cognitiva/genética , Estudios de Cohortes , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Escala del Estado Mental , Persona de Mediana Edad , Estudios Multicéntricos como Asunto , Pruebas Neuropsicológicas , Valor Predictivo de las Pruebas
15.
Curr Alzheimer Res ; 12(1): 69-79, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25523428

RESUMEN

We evaluated the performance of the Disease State Index (DSI) method when predicting progression to Alzheimer's disease (AD) in patients with subjective cognitive impairment (SCI), amnestic or non-amnestic mild cognitive impairment (aMCI, naMCI). The DSI model measures patients' similarity to diagnosed cases based on available data, such as cognitive tests, the APOE genotype, CSF biomarkers and MRI. We applied the DSI model to data from the DESCRIPA cohort, where non-demented patients (N=775) with different subtypes of cognitive impairment were followed for 1 to 5 years. Classification accuracies for the subgroups were calculated with the DSI using leave-one-out crossvalidation. The DSI's classification accuracy in predicting progression to AD was 0.75 (AUC=0.83) in the total population, 0.70 (AUC=0.77) for aMCI and 0.71 (AUC=0.76) for naMCI. For a subset of approximately half of the patients with high or low DSI values, accuracy reached 0.86 (all), 0.78 (aMCI), and 0.85 (naMCI). For patients with MRI or CSF biomarker data available, theywere 0.78 (all), 0.76 (aMCI) and 0.76 (naMCI), while for clear cases the accuracies rose to 0.90 (all), 0.83 (aMCI) and 0.91 (naMCI). The results show that the DSI model can distinguish between clear and ambiguous cases, assess the severity of the disease and also provide information on the effectiveness of different biomarkers. While a specific test or biomarker may confound analysis for an individual patient, combining several different types of tests and biomarkers could be able to reveal the trajectory of the disease and improve the prediction of AD progression.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/fisiopatología , Disfunción Cognitiva/fisiopatología , Progresión de la Enfermedad , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/líquido cefalorraquídeo , Apolipoproteínas E/genética , Área Bajo la Curva , Biomarcadores/líquido cefalorraquídeo , Disfunción Cognitiva/líquido cefalorraquídeo , Disfunción Cognitiva/genética , Europa (Continente) , Femenino , Humanos , Estudios Longitudinales , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Valor Predictivo de las Pruebas , Escalas de Valoración Psiquiátrica , Sensibilidad y Especificidad
16.
J Alzheimers Dis ; 39(1): 49-61, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24121959

RESUMEN

Several neuropsychological tests and biomarkers of Alzheimer's disease (AD) have been validated and their evolution over time has been explored. In this study, multiple heterogeneous predictors of AD were combined using a supervised learning method called Disease State Index (DSI). The behavior of DSI values over time was examined to study disease progression quantitatively in a mild cognitive impairment (MCI) cohort. The DSI method was applied to longitudinal data from 140 MCI cases that progressed to AD and 149 MCI cases that did not progress to AD during the follow-up. The data included neuropsychological tests, brain volumes from magnetic resonance imaging, cerebrospinal fluid samples, and apolipoprotein E from the Alzheimer's Disease Neuroimaging Initiative database. Linear regression of the longitudinal DSI values (including the DSI value at the point of MCI to AD conversion) was performed for each subject having at least three DSI values available (147 non-converters, 126 converters). Converters had five times higher slopes and almost three times higher intercepts than non-converters. Two subgroups were found in the group of non-converters: one group with stable DSI values over time and another group with clearly increasing DSI values suggesting possible progression to AD in the future. The regression parameters differentiated between the converters and the non-converters with classification accuracy of 76.9% for the slopes and 74.6% for the intercepts. In conclusion, this study demonstrated that quantifying longitudinal patient data using the DSI method provides valid information for follow-up of disease progression and support for decision making.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Disfunción Cognitiva/diagnóstico , Modelos Estadísticos , Anciano , Biomarcadores/análisis , Estudios de Cohortes , Presentación de Datos , Técnicas de Apoyo para la Decisión , Diagnóstico Diferencial , Progresión de la Enfermedad , Diagnóstico Precoz , Femenino , Estudios de Seguimiento , Humanos , Procesamiento de Imagen Asistido por Computador , Modelos Lineales , Estudios Longitudinales , Imagen por Resonancia Magnética , Masculino , Pruebas Neuropsicológicas , Curva ROC
17.
Stud Health Technol Inform ; 189: 77-82, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23739361

RESUMEN

As the amount of data acquired from humans is constantly increasing, efficient tools are needed for extracting relevant information from this data. This paper presents a Matlab implementation of a method to classify and visually explore (highly) multi-variate patient data. The method uses the so-called Disease State Index (DSI) which measures the fit of a test subject's data to two classes present in the data (e.g. 'controls' and 'positives'). DSI values of the different variables measured from a patient can be combined and visualized in a tree-like form using the Disease State Fingerprint (DSF) method. This allows a researcher to explore and understand the relevance of the different variables in classification problems. Moreover, the method is robust with respect to missing data. After giving an introduction to the DSF and DSI methods, the paper describes the steps required to use the methods and presents a MATLAB toolbox to perform these steps. To demonstrate the methods' versatility, the paper illustrates the usage of the toolbox in a few different contexts in which personal health data is to be classified. With this implementation, a powerful and flexible tool is made available to the biomedical research community.


Asunto(s)
Algoritmos , Sistemas de Apoyo a Decisiones Clínicas , Diagnóstico por Computador/métodos , Registros Electrónicos de Salud , Registros de Salud Personal , Programas Informáticos , Interfaz Usuario-Computador , Sistemas de Administración de Bases de Datos
18.
J Alzheimers Dis ; 35(4): 727-39, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23455991

RESUMEN

BACKGROUND: Disease state index and disease state fingerprint represent a novel tool which collates data information from different sources, helping the clinician in the diagnosis and follow-up of dementia diseases. It has been demonstrated that it is applicable in the diagnosis of Alzheimer's disease (AD). OBJECTIVE: We applied this novel tool to classify frontotemporal dementia (FTD) cases in comparison with controls, AD, and mild cognitive impairment (MCI) subjects. METHODS: Thirty seven patients with FTD, 35 patients with AD, 26 control subjects, and 64 subjects with MCI were included in the study. The disease state index encompassed data from cognitive performance assessed by Mini-Mental State Examination, cerebrospinal fluid biomarkers, MRI volumetric and morphometric parameters as well as APOE genotype. RESULTS: We applied the Disease State Index for comparisons at the group level. The data showed that FTD patients could be differentiated with a high accuracy, sensitivity, and specificity from controls (0.84, 0.84, 0.83) and from MCI (0.79, 0.78, 0.80). However, the correct accuracy was lower in the FTD versus AD comparison (0.69, 0.70, 0.71). In addition, we demonstrated the use of Disease State Fingerprint by comparing one particular FTD case with control, AD, and MCI population data. CONCLUSION: The results suggest that the Disease State Fingerprint and the underlying Disease State Index are particularly useful in differentiating between normal status and disease in patients with dementia, but it may also help to distinguish between the two dementia diseases, FTD and AD.


Asunto(s)
Enfermedad de Alzheimer/patología , Disfunción Cognitiva/patología , Demencia Frontotemporal/patología , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/psicología , Apolipoproteínas E/genética , Biomarcadores/líquido cefalorraquídeo , Disfunción Cognitiva/psicología , Femenino , Demencia Frontotemporal/psicología , Genotipo , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Memoria/fisiología , Persona de Mediana Edad , Pruebas Neuropsicológicas , Fenotipo
19.
PLoS One ; 8(2): e55246, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23424625

RESUMEN

PURPOSE: To compare the accuracies of predicting AD conversion by using a decision support system (PredictAD tool) and current research criteria of prodromal AD as identified by combinations of episodic memory impairment of hippocampal type and visual assessment of medial temporal lobe atrophy (MTA) on MRI and CSF biomarkers. METHODS: Altogether 391 MCI cases (158 AD converters) were selected from the ADNI cohort. All the cases had baseline cognitive tests, MRI and/or CSF levels of Aß1-42 and Tau. Using baseline data, the status of MCI patients (AD or MCI) three years later was predicted using current diagnostic research guidelines and the PredictAD software tool designed for supporting clinical diagnostics. The data used were 1) clinical criteria for episodic memory loss of the hippocampal type, 2) visual MTA, 3) positive CSF markers, 4) their combinations, and 5) when the PredictAD tool was applied, automatically computed MRI measures were used instead of the visual MTA results. The accuracies of diagnosis were evaluated with the diagnosis made 3 years later. RESULTS: The PredictAD tool achieved the overall accuracy of 72% (sensitivity 73%, specificity 71%) in predicting the AD diagnosis. The corresponding number for a clinician's prediction with the assistance of the PredictAD tool was 71% (sensitivity 75%, specificity 68%). Diagnosis with the PredictAD tool was significantly better than diagnosis by biomarkers alone or the combinations of clinical diagnosis of hippocampal pattern for the memory loss and biomarkers (p≤0.037). CONCLUSION: With the assistance of PredictAD tool, the clinician can predict AD conversion more accurately than the current diagnostic criteria.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Técnicas de Apoyo para la Decisión , Diagnóstico por Computador/métodos , Guías de Práctica Clínica como Asunto , Síntomas Prodrómicos , Programas Informáticos , Anciano , Disfunción Cognitiva/diagnóstico , Femenino , Humanos , Masculino , Sensibilidad y Especificidad
20.
Interface Focus ; 3(2): 20120072, 2013 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-24427524

RESUMEN

Alzheimer's disease (AD) is the most common cause of dementia affecting 36 million people worldwide. As the demographic transition in the developed countries progresses towards older population, the worsening ratio of workers per retirees and the growing number of patients with age-related illnesses such as AD will challenge the current healthcare systems and national economies. For these reasons AD has been identified as a health priority, and various methods for diagnosis and many candidates for therapies are under intense research. Even though there is currently no cure for AD, its effects can be managed. Today the significance of early and precise diagnosis of AD is emphasized in order to minimize its irreversible effects on the nervous system. When new drugs and therapies enter the market it is also vital to effectively identify the right candidates to benefit from these. The main objective of the PredictAD project was to find and integrate efficient biomarkers from heterogeneous patient data to make early diagnosis and to monitor the progress of AD in a more efficient, reliable and objective manner. The project focused on discovering biomarkers from biomolecular data, electrophysiological measurements of the brain and structural, functional and molecular brain images. We also designed and built a statistical model and a framework for exploiting these biomarkers with other available patient history and background data. We were able to discover several potential novel biomarker candidates and implement the framework in software. The results are currently used in several research projects, licensed to commercial use and being tested for clinical use in several trials.

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