RENATO ANGHINAH
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/45 - Laboratório de Fisiopatologia Neurocirúrgica, Hospital das Clínicas, Faculdade de Medicina
LIM/45 - Laboratório de Fisiopatologia Neurocirúrgica, Hospital das Clínicas, Faculdade de Medicina
7 resultados
Resultados de Busca
Agora exibindo 1 - 7 de 7
- Characterizing Alzheimer's Disease Severity via Resting-Awake EEG Amplitude Modulation Analysis(2013) FRAGA, Francisco J.; FALK, Tiago H.; KANDA, Paulo A. M.; ANGHINAH, RenatoChanges in electroencephalography (EEG) amplitude modulations have recently been linked with early-stage Alzheimer's disease (AD). Existing tools available to perform such analysis (e.g., detrended fluctuation analysis), however, provide limited gains in discriminability power over traditional spectral based EEG analysis. In this paper, we explore the use of an innovative EEG amplitude modulation analysis technique based on spectro-temporal signal processing. More specifically, full-band EEG signals are first decomposed into the five well-known frequency bands and the envelopes are then extracted via a Hilbert transform. Each of the five envelopes are further decomposed into four so-called modulation bands, which were chosen to coincide with the delta, theta, alpha and beta frequency bands. Experiments on a resting-awake EEG dataset collected from 76 participants (27 healthy controls, 27 diagnosed with mild-AD, and 22 with moderate-AD) showed significant differences in amplitude modulations between the three groups. Most notably, i) delta modulation of the beta frequency band disappeared with an increase in disease severity (from mild to moderate AD), ii) delta modulation of the theta band appeared with an increase in severity, and iii) delta modulation of the beta frequency band showed to be a reliable discriminant feature between healthy controls and mild-AD patients. Taken together, it is hoped that the developed tool can be used to assist clinicians not only with early detection of Alzheimer's disease, but also to monitor its progression.
- Index of alpha/theta ratio of the electroencephalogram: a new marker for Alzheimer's disease(2013) SCHMIDT, Magali T.; KANDA, Paulo A. M.; BASILE, Luis F. H.; LOPES, Helder Frederico da Silva; BARATHO, Regina; DEMARIO, Jose L. C.; JORGE, Mario S.; NARDI, Antonio E.; MACHADO, Sergio; IANOF, Jessica N.; NITRINI, Ricardo; ANGHINAH, RenatoObjective: We evaluated quantitative EEG measures to determine a screening index to discriminate Alzheimers disease (AD) patients from normal individuals. Methods: Two groups of individuals older than 50 years, comprising a control group of 57 normal volunteers and a study group of 50 patients with probable AD, were compared. EEG recordings were obtained from subjects in a wake state with eyes closed at rest for 30 min. Logistic regression analysis was conducted. Results: Spectral potentials of the alpha and theta bands were computed for all electrodes and the alpha/theta ratio calculated. Logistic regression of alpha/theta of the mean potential of the C3 and O1 electrodes was carried out. A formula was calculated to aid the diagnosis of AD yielding 76.4% sensitivity and 84.6% specificity for AD with an area under the ROC curve of 0.92. Conclusion: Logistic regression of alpha/theta of the spectrum of the mean potential of EEG represents a good marker discriminating AD patients from normal controls.
- BPSD following traumatic brain injury(2013) ANGHINAH, Renato; FREIRE, Fabio Rios; COELHO, Fernanda; LACERDA, Juliana Rhein; SCHMIDT, Magali Taino; CALADO, Vanessa Tomé Gonçalves; IANOF, Jéssica Natuline; MACHADO, Sergio; VELASQUES, Bruna; RIBEIRO, Pedro; BASILE, Luis Fernando Hindi; PAIVA, Wellingson Silva; AMORIM, Robson LuisABSTRACT Annually, 700,000 people are hospitalized with brain injury acquired after traumatic brain injury (TBI) in Brazil. Objective: We aim to review the basic concepts related to TBI, and the most common Behavioral and Psychological Symptoms of Dementia (BPSD) findings in moderate and severe TBI survivors. We also discussed our strategies used to manage such patients in the post-acute period. Methods: Fifteen TBI outpatients followed at the Center for Cognitive Rehabilitation Post-TBI of the Clinicas Hospital of the University of São Paulo were submitted to a neurological, neuropsychological, speech and occupational therapy evaluation, including the Mini-Mental State Examination. Rehabilitation strategies will then be developed, together with the interdisciplinary team, for each patient individually. Where necessary, the pharmacological approach will be adopted. Results: Our study will discuss options of pharmacologic treatment choices for cognitive, behavioral, or affective disorders following TBI, providing relevant information related to a structured cognitive rehabilitation service and certainly will offer an alternative for patients and families afflicted by TBI. Conclusion: Traumatic brain injury can cause a variety of potentially disabling psychiatric symptoms and syndromes. Combined behavioral and pharmacological strategies, in the treatment of a set of highly challenging behavioral problems, appears to be essential for good patient recovery.
- TOWARDS AN EEG-BASED BIOMARKER FOR ALZHEIMER'S DISEASE: IMPROVING AMPLITUDE MODULATION ANALYSIS FEATURES(2013) FRAGA, Francisco J.; FALK, Tiago H.; TRAMBAIOLLI, Lucas R.; OLIVEIRA, Eliezyer F.; PINAYA, Walter H. L.; KANDA, Paulo A. M.; ANGHINAH, RenatoIn this paper, an EEG-based biomarker for automated Alzheimer's disease (AD) diagnosis is described, based on extending a recently-proposed ""percentage modulation energy"" (PME) metric. More specifically, to improve the signal-to-noise ratio of the EEG signal, PME features were averaged over different durations prior to classification. Additionally, two variants of the PME features were developed: the ""percentage raw energy"" (PRE) and the ""percentage envelope energy"" (PEE). Experimental results on a dataset of 88 participants (35 controls, 31 with mild-AD and 22 with moderate AD) show that over 98% accuracy can be achieved with a support vector classifier when discriminating between healthy and mild AD patients, thus significantly outperforming the original PME biomarker. Moreover, the proposed system can achieve over 94% accuracy when discriminating between mild and moderate AD, thus opening doors for very early diagnosis.
- Lack of Systematic Topographic Difference between Attention and Reasoning Beta Correlates(2013) BASILE, Luis F. H.; SATO, Joao R.; ALVARENGA, Milkes Y.; HENRIQUE JR., Nelson; PASQUINI, Henrique A.; ALFENAS, William; MACHADO, Sergio; VELASQUES, Bruna; RIBEIRO, Pedro; PIEDADE, Roberto; ANGHINAH, Renato; RAMOS, Renato T.Based on previous evidence for individual-specific sets of cortical areas active during simple attention tasks, in this work we intended to perform within individual comparisons of task-induced beta oscillations between visual attention and a reasoning task. Since beta induced oscillations are not time-locked to task events and were first observed by Fourier transforms, in order to analyze the cortical topography of attention induced beta activity, we have previously computed corrected-latency averages based on spontaneous peaks of band-pass filtered epochs. We then used Independent Component Analysis (ICA) only to single out the significant portion of averaged data, above noise levels. In the present work ICA served as the main, exhaustive means for decomposing beta activity in both tasks, using 128-channel EEG data from 24 subjects. Given the previous observed similarity between tasks by visual inspection and by simple descriptive statistics, we now intended another approach: to quantify how much each ICA component obtained in one task could be explained by a linear combination of the topographic patterns from the other task in each individual. Our hypothesis was that the major psychological difference between tasks would not be reflected as important topographic differences within individuals. Results confirmed the high topographic similarity between attention and reasoning beta correlates in that few components in each individual were not satisfactorily explained by the complementary task, and if those could be considered ""task-specific"", their scalp distribution and estimated cortical sources were not common across subjects. These findings, along with those from fMRI studies preserving individual data and conventional neuropsychological and neurosurgical observations, are discussed in support of a new functional localization hypothesis: individuals use largely different sets of cortical association areas to perform a given task, but those individual sets do not change importantly across tasks that differ in major psychological processes.
conferenceObject Neuropsychological Evaluation in Patients Submitted to Cranioplasty: A Case Series(2013) COELHO, Fernanda; MAYNART, Arthur; FREIRE, Fabio; GONCALVES, Vanessa; ANDRADE, Almir; PAIVA, Wellingson; AMORIM, Robson; ANGHINAH, Renato- Time Perception Distortion in Neuropsychiatric and Neurological Disorders(2013) TEIXEIRA, Silmar; MACHADO, Sergio; PAES, Flavia; VELASQUES, Bruna; SILVA, Julio Guilherme; SANFIM, Antonio L.; MINC, Daniel; ANGHINAH, Renato; MENEGALDO, Luciano L.; SALAMA, Mohamed; CAGY, Mauricio; NARDI, Antonio E.; POEPPEL, Ernst; BAO, Yan; SZELAG, Elzbieta; RIBEIRO, Pedro; ARIAS-CARRION, OscarThere is no sense organ specifically dedicated to time perception, as there is for other senses such as hearing and vision. However, this subjective sense of time is fundamental to our conception of reality and it creates the temporal course of events in our lives. Here, we explored neurobiological relations from the clinical perspective, examining timing ability in patients with different neurological and psychiatric conditions (e.g. Parkinson's disease, depression, bipolar disorder, anxiety disorders and schizophrenia). The neural bases of present distortions in time perception and temporal information processing still remain poorly understood. We reviewed: a) how the brain is capable of encoding time in different environments and multiple tasks, b) different models of interval timing, c) brain structures and neurotransmitters associated with time perception, d) the relationship between memory and time perception, e) neural mechanisms underlying different theories in neural and mental processes, and f) the relationship between different mental diseases and time perception. Bibliographic research was conducted based on publications over the past thirteen years written in English in the databases Scielo, Pubmed/MEDLINE, ISI Web of Knowledge. The time perceptions research are executed to evaluate time perception in mental diseases and can provide evidence for future clinical applications.