Permutation entropy and irreversibility in gait kinematic time series from patients with mild cognitive decline and early Alzheimer’s dementia

Permutation entropy; Irreversibility; Mild cognitive impairmentEntropía de permutación; Irreversibilidad; Defecto cognitivo leveEntropia de permutació; Irreversibilitat; Deteriorament cognitiu lleuGait is a basic cognitive purposeful action that has been shown to be altered in late stages of neurodegenerative dementias. Nevertheless, alterations are less clear in mild forms of dementia, and the potential use of gait analysis as a biomarker of initial cognitive decline has hitherto mostly been neglected. Herein, we report the results of a study of gait kinematic time series for two groups of patients (mild cognitive impairment and mild Alzheimer’s disease) and a group of matched control subjects. Two metrics based on permutation patterns are considered, respectively measuring the complexity and irreversibility of the time series. Results indicate that kinematic disorganisation is present in early phases of cognitive impairment; in addition, they depict a rich scenario, in which some joint movements display an increased complexity and irreversibility, while others a marked decrease. Beyond their potential use as biomarkers, complexity and irreversibility metrics can open a new door to the understanding of the role of the nervous system in gait, as well as its adaptation and compensatory mechanisms.This research was funded through the Premio del Ilustre Colegio Profesional de Fisioterapeutas de la Comunidad De Madrid, prize number ICPFM-IX-2013

Permutation entropy and irreversibility in gait kinematic time series from patients with mild cognitive decline and early alzheimer’s dementia

Gait is a basic cognitive purposeful action that has been shown to be altered in late stages of neurodegenerative dementias. Nevertheless, alterations are less clear in mild forms of dementia, and the potential use of gait analysis as a biomarker of initial cognitive decline has hitherto mostly been neglected. Herein, we report the results of a study of gait kinematic time series for two groups of patients (mild cognitive impairment and mild Alzheimer’s disease) and a group of matched control subjects. Two metrics based on permutation patterns are considered, respectively measuring the complexity and irreversibility of the time series. Results indicate that kinematic disorganisation is present in early phases of cognitive impairment; in addition, they depict a rich scenario, in which some joint movements display an increased complexity and irreversibility, while others a marked decrease. Beyond their potential use as biomarkers, complexity and irreversibility metrics can open a new door to the understanding of the role of the nervous system in gait, as well as its adaptation and compensatory mechanismsThis research was funded through the Premio del Ilustre Colegio Profesional de Fisioterapeutas de la Comunidad De Madrid, prize number ICPFM-IX-201

Conditions associated with REM sleep behaviour disorder: description of a hospital series

Introducción: El trastorno de conducta de sueño REM (TCSR) se caracteriza por conductas violentas (gritos, patadas, sueños vívidos) durante la fase REM del sueño. Tiene una prevalencia del 1-2% de la población general, especialmente en varones y en mayores de 60 años. En la última década se ha asociado como pródromo a una enfermedad neurodegenerativa. Nos proponemos analizar las patologías asociadas a los 33 pacientes con TCSR atendidos en la Unidad Multidisciplinar de Trastornos del Sueño del Hospital Infanta Sofía, y su respuesta al tratamiento farmacológico. Pacientes y métodos: Análisis descriptivo, retrospectivo, observacional, de los pacientes con diagnóstico de TCSR, atendidos en la consulta monográfica de Neurología, desde octubre de 2012 hasta diciembre de 2015. Se valoran la edad, el sexo, las enfermedades asociadas, y los tratamientos empleados. Resultados: De los 365 pacientes valorados en la consulta, 33 presentan TCSR: 13 mujeres (40%) y 20 hombres (60%), con una edad media de 62,72 años. En el 48% se identifica una patología asociada: la más frecuente es el deterioro cognitivo leve (69%). El porcentaje de TCSR con patología asociada en mayores de 60 años se eleva al 68%. El 82% de los casos han requerido tratamiento. El fármaco más utilizado ha sido el clonazepam (76%), seguido de melatonina (9%), gabapentina (6%) y trazodona (3%). Discusión: En nuestra serie el 48% de los pacientes presentan una patología asociada. La mayor edad influye directamente en la posibilidad de encontrar una patología asociada. La gran mayoría han precisado tratamiento farmacológico por la severidad de los síntomas, siendo el clonazepam (76%) el fármaco más utilizado.IIntroduction: REM sleep behaviour disorder (RBD) is characterised by violent behaviours (screaming, kicking, vivid dreams) during REM sleep. It has a prevalence of 1% to 2% of the general population and is especially frequent in men and the population older than 60. In the last decade, RBD has been suggested to be a prodrome of neurodegenerative disease. We analysed associated neurological diseases and responses to drug treatment in 33 patients with RBD treated in the multidisciplinary sleep disorders unit at Hospital Infanta Sofía. Patients and methods: We conducted an observational descriptive retrospective analysis of patients diagnosed with RBD and treated in our multidisciplinary sleep disorders unit between October 2012 and December 2015. We recorded age, sex, associated diseases, and treatments administered to these patients. Results: A total of 365 patients were attended at our unit, including 33 with RBD: 13 women (40%) and 20 men (60%). Mean age was 62.72 years. An associated disorder was identified in 48%, with the most common being mild cognitive impairment (69%). The percentage of patients with RBD and an associated disorder among patients older than 60 was 68%. Eighty-two percent of the patients required treatment. The most commonly used drug was clonazepam (76%), followed by melatonin (9%), gabapentin (6%), and trazodone (3%). Discussion: In our series, 48% of the patients had an associated disorder. The likelihood of detecting an associated disorder increases with patients’ age. The vast majority of patients required drug treatment due to symptom severity; the most frequently administered drug was clonazepam (76%).Sin financiación1.938 JCR (2017) Q3, 136/197 Clinical Neurology0.534 SJR (2017) Q2, 1260/2878 Medicine (miscellaneous)No data IDR 2017UE