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University of Pretoria

1. Negrao, Bianca Lee. Autonomic correlates at rest and during evoked attention in children with attention-deficit/hyperactivity disorder and effects of sympathomimetic medication.

Degree: Physiology, 2009, University of Pretoria

Indications are that autonomic under-arousal exists in children with ADHD. Published results are, however, controversial and few studies examine the relationship between the autonomic nervous system and focussed attention. In line with the indications of sympathetic under-arousal, patients with the disorder are treated with sympathomimetic stimulants such as Ritalin (methylphenidate). Since these medications stimulate the sympathetic nervous system, they possess the potential to influence cardiac function. The aims of this study were a) to assess autonomic nervous system functioning in 20 children with ADHD, as compared to controls, and to examine the effects of focussed attention and sympathomimetic medication on this system, b) to investigate cardiac functioning in 20 children with ADHD, as compared to controls, and to examine the effects of sympathomimetic medication on this system and c) to assess EEG functioning in children with ADHD, as compared to controls, and to examine the effects of sympathomimetic medication on this functioning. Children with ADHD were tested while they were stimulant-free and during a period in which they were on stimulant medication, while controls were tested once. Autonomic nervous system activity of the children was assessed at baseline and during focussed attention by means of heart rate variability (HRV) and skin conductivity. Attention was evoked by means of a program on the BioGraph Infiniti biofeedback apparatus, which is used specifically to train ADHD individuals to increase their attentive abilities. HRV was determined by time-domain, frequency-domain and PoincarĂ© analysis of RR interval data. Skin conductivity was determined by BioGraph Infiniti biofeedback apparatus. Cardiac functioning of the children was assessed at baseline by means of blood pressure recordings and electrocardiograms (ECGs). Blood pressure was measured by means of a stethoscope and mercurial sphygmomanometer. ECGs were obtained by means of a Schiller CardioLaptop AT-110 ECG recorder using the standard 12-lead cable positioning for a resting ECG and parameters measured included HR, RR, QT, JT, QTc, JTc, QTd, JTd, QTcd and JTcd. EEG values were determined at baseline and during focussed attention by means of BioGraph Infiniti biofeedback apparatus. EEG values measured in this study included theta/beta ratios, theta/SMR ratios and thalpha, low alpha and high alpha power. The main findings of this study are that: Stimulant-free ADHD children show a parasympathetic dominance of the sympathovagal balance relative to controls. Methylphenidate usage shifts the autonomic balance of children with ADHD towards normal levels; however a normal autonomic balance is not reached. Stimulant-free ADHD children exhibit a shift in the sympathovagal balance towards the sympathetic nervous system from baseline to focussed attention; however, methylphenidate abolishes this shift. Methylphenidate usage does not, in general, cause QTc or JTc prolongation but it may cause QTc or JTc… Advisors/Committee Members: Prof M Viljoen (advisor).

Subjects/Keywords: Sympathovagal balance; Autonomic nervous system; Ritalin; Methylphenidate; Electrocardiograms; Theta/beta ratios; Adhd; Theta/smr ratios; Alpha waves; Focussed attention; Heart rate variability; Skin conductivity; Cardiac function; Blood pressure; UCTD

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Negrao, B. L. (2009). Autonomic correlates at rest and during evoked attention in children with attention-deficit/hyperactivity disorder and effects of sympathomimetic medication. (Masters Thesis). University of Pretoria. Retrieved from http://hdl.handle.net/2263/26102

Chicago Manual of Style (16th Edition):

Negrao, Bianca Lee. “Autonomic correlates at rest and during evoked attention in children with attention-deficit/hyperactivity disorder and effects of sympathomimetic medication.” 2009. Masters Thesis, University of Pretoria. Accessed August 05, 2020. http://hdl.handle.net/2263/26102.

MLA Handbook (7th Edition):

Negrao, Bianca Lee. “Autonomic correlates at rest and during evoked attention in children with attention-deficit/hyperactivity disorder and effects of sympathomimetic medication.” 2009. Web. 05 Aug 2020.

Vancouver:

Negrao BL. Autonomic correlates at rest and during evoked attention in children with attention-deficit/hyperactivity disorder and effects of sympathomimetic medication. [Internet] [Masters thesis]. University of Pretoria; 2009. [cited 2020 Aug 05]. Available from: http://hdl.handle.net/2263/26102.

Council of Science Editors:

Negrao BL. Autonomic correlates at rest and during evoked attention in children with attention-deficit/hyperactivity disorder and effects of sympathomimetic medication. [Masters Thesis]. University of Pretoria; 2009. Available from: http://hdl.handle.net/2263/26102


University of Pretoria

2. [No author]. Autonomic correlates at rest and during evoked attention in children with attention-deficit/hyperactivity disorder and effects of sympathomimetic medication .

Degree: 2009, University of Pretoria

Indications are that autonomic under-arousal exists in children with ADHD. Published results are, however, controversial and few studies examine the relationship between the autonomic nervous system and focussed attention. In line with the indications of sympathetic under-arousal, patients with the disorder are treated with sympathomimetic stimulants such as Ritalin (methylphenidate). Since these medications stimulate the sympathetic nervous system, they possess the potential to influence cardiac function. The aims of this study were a) to assess autonomic nervous system functioning in 20 children with ADHD, as compared to controls, and to examine the effects of focussed attention and sympathomimetic medication on this system, b) to investigate cardiac functioning in 20 children with ADHD, as compared to controls, and to examine the effects of sympathomimetic medication on this system and c) to assess EEG functioning in children with ADHD, as compared to controls, and to examine the effects of sympathomimetic medication on this functioning. Children with ADHD were tested while they were stimulant-free and during a period in which they were on stimulant medication, while controls were tested once. Autonomic nervous system activity of the children was assessed at baseline and during focussed attention by means of heart rate variability (HRV) and skin conductivity. Attention was evoked by means of a program on the BioGraph Infiniti biofeedback apparatus, which is used specifically to train ADHD individuals to increase their attentive abilities. HRV was determined by time-domain, frequency-domain and PoincarĂ© analysis of RR interval data. Skin conductivity was determined by BioGraph Infiniti biofeedback apparatus. Cardiac functioning of the children was assessed at baseline by means of blood pressure recordings and electrocardiograms (ECGs). Blood pressure was measured by means of a stethoscope and mercurial sphygmomanometer. ECGs were obtained by means of a Schiller CardioLaptop AT-110 ECG recorder using the standard 12-lead cable positioning for a resting ECG and parameters measured included HR, RR, QT, JT, QTc, JTc, QTd, JTd, QTcd and JTcd. EEG values were determined at baseline and during focussed attention by means of BioGraph Infiniti biofeedback apparatus. EEG values measured in this study included theta/beta ratios, theta/SMR ratios and thalpha, low alpha and high alpha power. The main findings of this study are that: Stimulant-free ADHD children show a parasympathetic dominance of the sympathovagal balance relative to controls. Methylphenidate usage shifts the autonomic balance of children with ADHD towards normal levels; however a normal autonomic balance is not reached. Stimulant-free ADHD children exhibit a shift in the sympathovagal balance towards the sympathetic nervous system from baseline to focussed attention; however, methylphenidate abolishes this shift. Methylphenidate usage does not, in general, cause QTc or JTc prolongation but it may cause QTc or JTc… Advisors/Committee Members: Prof M Viljoen (advisor).

Subjects/Keywords: Sympathovagal balance; Autonomic nervous system; Ritalin; Methylphenidate; Electrocardiograms; Theta/beta ratios; Adhd; Theta/smr ratios; Alpha waves; Focussed attention; Heart rate variability; Skin conductivity; Cardiac function; Blood pressure; UCTD

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

author], [. (2009). Autonomic correlates at rest and during evoked attention in children with attention-deficit/hyperactivity disorder and effects of sympathomimetic medication . (Masters Thesis). University of Pretoria. Retrieved from http://upetd.up.ac.za/thesis/available/etd-07072009-163036/

Chicago Manual of Style (16th Edition):

author], [No. “Autonomic correlates at rest and during evoked attention in children with attention-deficit/hyperactivity disorder and effects of sympathomimetic medication .” 2009. Masters Thesis, University of Pretoria. Accessed August 05, 2020. http://upetd.up.ac.za/thesis/available/etd-07072009-163036/.

MLA Handbook (7th Edition):

author], [No. “Autonomic correlates at rest and during evoked attention in children with attention-deficit/hyperactivity disorder and effects of sympathomimetic medication .” 2009. Web. 05 Aug 2020.

Vancouver:

author] [. Autonomic correlates at rest and during evoked attention in children with attention-deficit/hyperactivity disorder and effects of sympathomimetic medication . [Internet] [Masters thesis]. University of Pretoria; 2009. [cited 2020 Aug 05]. Available from: http://upetd.up.ac.za/thesis/available/etd-07072009-163036/.

Council of Science Editors:

author] [. Autonomic correlates at rest and during evoked attention in children with attention-deficit/hyperactivity disorder and effects of sympathomimetic medication . [Masters Thesis]. University of Pretoria; 2009. Available from: http://upetd.up.ac.za/thesis/available/etd-07072009-163036/

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