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1.
Neuroimage ; 293: 120623, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38670442

RESUMO

High-order interactions are required across brain regions to accomplish specific cognitive functions. These functional interdependencies are reflected by synergistic information that can be obtained by combining the information from all the sources considered and redundant information (i.e., common information provided by all the sources). However, electroencephalogram (EEG) functional connectivity is limited to pairwise interactions thereby precluding the estimation of high-order interactions. In this multicentric study, we used measures of synergistic and redundant information to study in parallel the high-order interactions between five EEG electrodes during three non-ordinary states of consciousness (NSCs): Rajyoga meditation (RM), hypnosis, and auto-induced cognitive trance (AICT). We analyzed EEG data from 22 long-term Rajyoga meditators, nine volunteers undergoing hypnosis, and 21 practitioners of AICT. We here report the within-group changes in synergy and redundancy for each NSC in comparison with their respective baseline. During RM, synergy increased at the whole brain level in the delta and theta bands. Redundancy decreased in frontal, right central, and posterior electrodes in delta, and frontal, central, and posterior electrodes in beta1 and beta2 bands. During hypnosis, synergy decreased in mid-frontal, temporal, and mid-centro-parietal electrodes in the delta band. The decrease was also observed in the beta2 band in the left frontal and right parietal electrodes. During AICT, synergy decreased in delta and theta bands in left-frontal, right-frontocentral, and posterior electrodes. The decrease was also observed at the whole brain level in the alpha band. However, redundancy changes during hypnosis and AICT were not significant. The subjective reports of absorption and dissociation during hypnosis and AICT, as well as the mystical experience questionnaires during AICT, showed no correlation with the high-order measures. The proposed study is the first exploratory attempt to utilize the concepts of synergy and redundancy in NSCs. The differences in synergy and redundancy during different NSCs warrant further studies to relate the extracted measures with the phenomenology of the NSCs.


Assuntos
Estado de Consciência , Eletroencefalografia , Hipnose , Meditação , Humanos , Masculino , Feminino , Adulto , Estado de Consciência/fisiologia , Pessoa de Meia-Idade , Encéfalo/fisiologia , Adulto Jovem
2.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 787-790, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34891408

RESUMO

Meditation practices are considered mental training and have increasingly received attention from the scientific community due to their potential psychological and physical health benefits. We compared the EEG data recorded from long-term rajayoga practitioners during different meditative and non-meditative periods. Minimum variance modified fuzzy entropy (MVMFE) is computed for each EEG band for all channels of a given lobe. The means across all the channel entropy values were obtained and compared during meditative and non-meditative states. Meditators showed higher frontal entropy in the lower gamma band (25-45Hz) during the meditative states. Independent component analysis was applied to ensure that muscle or eye artifacts did not contribute to the gamma activity. Our results extend previous findings on the changes in entropy observed in long-term meditators during rajayoga practice. Gamma band in EEG is implicated in cognitive processes requiring high-level processing such as attention, learning, memory control, and retrieval. Gamma activity is also suggested as a potential biomarker for therapeutic progress in patients with clinical depression. Based on our findings, there is an excellent possibility to utilize the practice of meditation as a training tool to strengthen the neural circuits, where age-related degeneration is making its pathological impact.


Assuntos
Meditação , Artefatos , Entropia , Lobo Frontal , Humanos
3.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2667-2670, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018555

RESUMO

This paper reports an interesting phenomenon that the amplitude of the QRS complex reduces during inhalation and increases during exhalation and the variation can exceed even 100% during very slow breathing rates (BR). The phenomenon has been consistent in all the nine normal male subjects we have studied with age ranging from 23 to 61 years. Further, at very low respiration rates which included breath holds both after inhalation and exhalation, there are highly significant second and third harmonics of the respiration frequency in the heart rate variability spectrum. On the other hand, the R-wave amplitude changes do not have any noticeable higher harmonics of the BR. Thus, the observed changes in the R-wave amplitude are neither connected to the movement of the heart nor changes in its relative position with respect to the recording electrodes nor the fluctuations in the stroke volume.


Assuntos
Suspensão da Respiração , Taxa Respiratória , Expiração , Frequência Cardíaca , Humanos , Masculino , Respiração
4.
Diagn Interv Imaging ; 99(11): 699-707, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30006125

RESUMO

PURPOSE: To evaluate the role of SWE in characterizing breast masses and ascertain whether additional use of SWE to ultrasound for evaluating BI-RADS 3 and 4a masses could help reduce long-term follow-up and unnecessary biopsies of these suspicious breast masses. MATERIALS AND METHODS: This prospective, cross-sectional study was performed between June 2013 and November 2014. All enrolled patients underwent clinical breast examination, ultrasound, SWE and ultrasound-guided core biopsy of the breast mass. Breast Imaging Reporting and Data System (BI-RAD) categories were assigned to breast masses. For qualitative and quantitative variables of SWE, cut-off values for differentiation between benign and malignant breast masses were estimated. Modified BIRADS' (up/downgrading of BIRADS category) was done for BI-RADS 3/4a masses by combining individual SWE parameters and ultrasound findings. Sensitivity, specificity, positive and negative predictive value of modified BI-RADS' and ultrasound BI-RADS were compared. RESULTS: A total of 119 women (mean age, 42.3±13.6 [SD] years; range: 13-87 years) with a single breast mass each were enrolled. Histopathologically, 57/119 (48%) breast masses were benign and 62 (52%) were malignant. On ultrasound, 42 breast masses were BI-RADS3 and 77 were BI-RADS 4 (4a, n=10; 4b, n=24; 4c, n=43) leading to 96.8% sensitivity and 70.2% specificity. On SWE, benign breast masses were oval/round, homogenous/reasonably homogenous, blue/green with lower elasticity values and malignant breast masses were irregular, inhomogeneous, red/orange with high elasticity values. On modified BI-RADS' using E-color and E-mean/E-max, specificity improved to 78.9% and 75.4% respectively. CONCLUSION: Addition of SWE to ultrasound improves characterization of BI-RADS 3 and 4a masses. E-max, E-mean and E-color are the most useful SWE parameters to differentiate between malignant and benign breast masses.


Assuntos
Doenças Mamárias/diagnóstico por imagem , Técnicas de Imagem por Elasticidade , Ultrassonografia Mamária , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
5.
J Pharm Bioallied Sci ; 7(Suppl 2): S776-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26538967

RESUMO

Facial nerve disorders may be of sudden onset and more often of unknown etiology. Edema of the facial nerve within the fallopian canal results in Bell's palsy. This causes compression of the nerve and affects the microcirculation. Many authors have suggested treatment for facial nerve paralysis ranging from simple physiotherapy to complicated microvascular decompression. It more often results in symptoms like synkinesis and muscle spasm after the decompression surgery of the nerve because of the inability to arrange the nerve fibers within the canal. The treatment choice also depends on patient's age, extent of the nerve damage, and patient's needs and desires. Many patients who cannot be rehabilitated functionally can be treated for esthetics of the involved muscles. This case report elaborates about a patient who was rehabilitated for esthetics and to some extent for function.

6.
Indian J Clin Biochem ; 28(4): 426-8, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24426249

RESUMO

Extensive research has demonstrated the protective properties of antioxidants, which scavenge reactive oxygen species and their precursors, as well as up-regulate enzymes involved in the repair of cellular damage. Several case-control studies have showed higher blood levels of antioxidants and decreased oxidative stress in younger individuals when compared with older ones. Cell damage caused by free radicals appears to be a major contributor in aging and degenerative diseases of aging such as cancer, cardiovascular disease, cataracts, compromised immune system, rheumatoid arthritis and brain dysfunction. The objective of this study was to determine the variation of Circulating levels of selected antioxidants (enzymic and non enzymic) and oxidative stress marker in younger and older humans. The results showed that a majority of the younger age group participants showed a significant increase in enzymic and nonenzymic antioxidant status and a decrease in oxidative stress when compared with the older age group.

7.
Indian J Psychiatry ; 49(4): 250-5, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20680136

RESUMO

BACKGROUND: Obsessive-compulsive disorder (OCD) is considered a heterogeneous disorder. One of the traditional approaches to subtype OCD is based on the predominance of obsessions, compulsions or both. Some studies suggest that the "predominantly obsessive" subtype of OCD may have poor outcome, whereas few other studies suggest that "mixed" OCD is associated with poor outcome. Therefore, it is not clear if the long-term course of "predominantly obsessive" subjects is different from those with "mixed" OCD. In the establishment of diagnostic validity of psychiatric conditions, differential course is an important validating factor. AIM: This study compares the 5-6 year course of the "predominantly obsessive" subtype with that of the "mixed" subtype of OCD with the objective of determining if the course of OCD differs according to subtypes and whether course could be a validating factor for subtyping OCD based on predominance of obsessions, compulsions or both. SETTING AND DESIGN: Tertiary hospital, institutional setting. The study has a retrospective cohort design. MATERIALS AND METHODS: Fifty-four subjects with "predominantly obsessions" and an equal number of the "mixed" subtype of OCD were recruited from the database of a specialty OCD clinic of a major psychiatric hospital. They were followed up after 5-6 years. The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) checklist and severity rating scale was used for assessing OCD. The course of OCD was determined according to predefined criteria. STATISTICS: The Chi-square/Fisher's exact test and the independent samples "t" test were used to compare categorical and continuous variables, respectively. Correlations were tested using the Pearson's correlation analysis. RESULTS: Thirty-eight "predominantly obsessive" (70%) and 39 "mixed" (72%) OCD subjects could be traced and evaluated. The course of illness was similar in the two subtypes. A majority of the sample (72%) did not have clinical OCD at follow-up. CONCLUSIONS: "Predominantly obsessive" subjects have a course similar to those with "mixed" OCD. Clinically, it is reassuring to know that obsessive subjects do not have an unfavorable course as was suggested by some previous studies. In this sample, course did not validate the subtyping method employed, but it would be premature to conclude that the subtyping method employed is incorrect based on the course alone. Prospective study of the course in larger samples and neurobiological and family-genetic data may help further validation.

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