Lack of contextual-word predictability during reading in patients with mild Alzheimer disease.

In the present work we analyzed the effect of contextual word predictability on the eye movement behavior of patients with mild Alzheimer disease (AD) compared to age-matched controls, by using the eyetracking technique and lineal mixed models. Twenty AD patients and 40 age-matched controls participated in the study. We first evaluated gaze duration during reading low and highly predictable sentences. AD patients showed an increase in gaze duration, compared to controls, both in sentences of low or high predictability. In controls, highly predictable sentences led to shorter gaze durations; by contrary, AD patients showed similar gaze durations in both types of sentences. Similarly, gaze duration in controls was affected by the cloze predictability of word N and N+1, whereas it was the same in AD patients. In contrast, the effects of word frequency and word length were similar in controls and AD patients. Our results imply that contextual-word predictability, whose processing is proposed to require memory retrieval, facilitated reading behavior in healthy subjects, but this facilitation was lost in early AD patients. This loss might reveal impairments in brain areas such as those corresponding to working memory, memory retrieval, and semantic memory functions that are already present at early stages of AD. In contrast, word frequency and length processing might require less complex mechanisms, which were still retained by AD patients. To the best of our knowledge, this is the first study measuring how patients with early AD process well-defined words embedded in sentences of high and low predictability. Evaluation of the resulting changes in eye movement behavior might provide a useful tool for a more precise early diagnosis of AD.

ENCOMS: Argentinian survey in cost of illness and unmet needs in multiple sclerosis.

UNLABELLED: The objective of the study was to assess the cost of multiple sclerosis (MS) patients in Argentina categorized by disease severity using a societal perspective. METHOD: Cross-sectional study including MS patients from 21 MS centers in 12 cities of Argentina. Patients were stratified by disease severity using the expanded disability status scale (EDSS) (group 1 with EDSS score between 0 and 3; group 2 with EDSS >3 and <7; group 3 with EDSS ≥7). Direct and indirect costs were analyzed for the second quarter of 2012 from public sources and converted to US Dollars. RESULTS: 266 patients were included. Mean annual cost per MS patient was USD 36,025 (95%CI 31,985-38,068) for patients with an EDSS between 0-3; USD 40,705 (95%CI 37,199-46,300) for patients with EDSS >3 and <7, and USD 50,712 (95%CI 47,825-62,104) for patients with EDSS ≥7. CONCLUSIONS: This is the first Argentine study evaluating the costs of MS considering disease severity.

ENCOMS: Argentinian survey in cost of illness and unmet needs in multiple sclerosis / ENCOMS: encuesta argentina sobre costos de la enfermedad y necesidades no cubiertas en pacientes con esclerosis múltiple

The objective of the study was to assess the cost of multiple sclerosis (MS) patients in Argentina categorized by disease severity using a societal perspective. Method: Cross-sectional study including MS patients from 21 MS centers in 12 cities of Argentina. Patients were stratified by disease severity using the expanded disability status scale (EDSS) (group 1 with EDSS score between 0 and 3; group 2 with EDSS >3 and <7; group 3 with EDSS ≥7). Direct and indirect costs were analyzed for the second quarter of 2012 from public sources and converted to US Dollars. Results: 266 patients were included. Mean annual cost per MS patient was USD 36,025 (95%CI 31,985-38,068) for patients with an EDSS between 0-3; USD 40,705 (95%CI 37,199-46,300) for patients with EDSS >3 and <7, and USD 50,712 (95%CI 47,825-62,104) for patients with EDSS ≥7. Conclusions: This is the first Argentine study evaluating the costs of MS considering disease severity. .

El objetivo del estudio fue evaluar el costo de los pacientes con esclerosis múltiple (EM) en Argentina categorizados por severidad de la enfermedad. Método: Estudio de corte transversal que incluyó pacientes con EM en 12 ciudades de Argentina. Los pacientes se estratificaron según expanded disability status scale (EDSS) (grupo 1 EDSS entre 0 y 3; grupo 2 EDDS >3 y <7; grupo 3 EDSS ≥7). Los costos directos e indirectos fueron analizados para el segundo trimestre de 2012 y convertidos a dólares estadounidenses. Resultados: 266 pacientes fueron incluidos. El coste medio anual por paciente con EM fue de USD 36,025 (31,985-38,068 IC95%) para los pacientes con un EDSS entre 0-3; USD 40,705 (37,199-46,300 IC95%) para los pacientes con EDSS >3 y <7 y USD 50,712 (47,825-62,104 IC95%) para los pacientes con EDSS ≥7. Conclusiones: Primer estudio argentino evaluar los costes de la EM considerado la gravedad de la enfermedad. .

Registering eye movements during reading in Alzheimer's disease: difficulties in predicting upcoming words.

Reading requires the fine integration of attention, ocular movements, word identification, and language comprehension, among other cognitive parameters. Several of the associated cognitive processes such as working memory and semantic memory are known to be impaired by Alzheimer's disease (AD). This study analyzes eye movement behavior of 18 patients with probable AD and 40 age-matched controls during Spanish sentence reading. Controls focused mainly on word properties and considered syntactic and semantic structures. At the same time, controls' knowledge and prediction about sentence meaning and grammatical structure are quite evident when we consider some aspects of visual exploration, such as word skipping, and forward saccades. By contrast, in the AD group, the predictability effect of the upcoming word was absent, visual exploration was less focused, fixations were much longer, and outgoing saccade amplitudes were smaller than those in controls. The altered visual exploration and the absence of a contextual predictability effect might be related to impairments in working memory and long-term memory retrieval functions. These eye movement measures demonstrate considerable sensitivity with respect to evaluating cognitive processes in Alzheimer's disease. They could provide a user-friendly marker of early disease symptoms and of its posterior progression.

Eye movement alterations during reading in patients with early Alzheimer disease.

PURPOSE: Eye movements follow a reproducible pattern during normal reading. Each eye movement ends up in a fixation point, which allows the brain to process the incoming information and to program the following saccade. Alzheimer disease (AD) produces eye movement abnormalities and disturbances in reading. In this work, we investigated whether eye movement alterations during reading might be already present at very early stages of the disease. METHODS: Twenty female and male adult patients with the diagnosis of probable AD and 20 age-matched individuals with no evidence of cognitive decline participated in the study. Participants were seated in front of a 20-inch LCD monitor and single sentences were presented on it. Eye movements were recorded with an eye tracker, with a sampling rate of 1000 Hz and an eye position resolution of 20 arc seconds. RESULTS: Analysis of eye movements during reading revealed that patients with early AD decreased the amount of words with only one fixation, increased their total number of first- and second-pass fixations, the amount of saccade regressions and the number of words skipped, compared with healthy individuals (controls). They also reduced the size of outgoing saccades, simultaneously increasing fixation duration. CONCLUSIONS: The present study shows that patients with mild AD evidenced marked alterations in eye movement behavior during reading, even at early stages of the disease. Hence, evaluation of eye movement behavior during reading might provide a useful tool for a more precise early diagnosis of AD and for dynamical monitoring of the pathology.