論文研討：A Combined fMRI and Heart Rate Variability Paradigm for Assessment of Central Autonomic Modulation

論文網址：IEEE Xplore

A Combined fMRI and Heart Rate Variability Paradigm for Assessment of Central Autonomic Modulation
Riccardo Barbieri; Giulia Conti; Rupali Dhond; Emery N. Brown; Vitaly Napadow

2007 3rd International IEEE/EMBS Conference on Neural Engineering
Year: 2007
Pages: 615 - 618, DOI: 10.1109/CNE.2007.369747
IEEE Conference Publications


Abstract

While the central autonomic network (CAN) has been adequately defined in animal models, data from the human have been lacking. In this study, we correlated cardiac-gated fMRI data with continuous-time heart rate variability (HRV) assessment in order to estimate central autonomic processing in response to a dynamic grip task. The electrocardiogram (ECG) was collected simultaneously with fMRI, and was analyzed with a new point process adaptive filter algorithm for evaluation of HRV indices reflecting time-varying dynamics of autonomic modulation. These were correlated with fMRI signal intensity using a general linear model and subsequent analysis of covariance. Our combined HRV-fMRI data analysis suggests that fMRI activity in several brain regions, including the hypothalamus, parabrachial nucleus, periaqueductal gray, amygdala, and posterior insula, demonstrated significant correlation with parasympathetic tone assessed by HRV high frequency (HF) power. This study demonstrates that inter-subject variability in brain response to an exercise task may help explain the natural variability in autonomic response, as assessed by HRV analysis

論文研討：Cerebral cortex and sub-cortex lateralization in cardiovascular regulation: Correlations of BOLD fMRI and heart rate variability

論文網址：IEEE Xplore


Cerebral cortex and sub-cortex lateralization in cardiovascular regulation: Correlations of BOLD fMRI and heart rate variability

P. Kuoppa; E. Niskanen; P. Karjalainen; M. P. Tarvainen

2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Year: 2012
Pages: 3412 - 3415, DOI: 10.1109/EMBC.2012.6346698
IEEE Conference Publications

Abstract

The role of cerebral cortex in cardiovascular regulation has not yet been mapped in detail. Especially the lateralization of different regions that are connected to cardiovascular modulation is still unknown. In this study we used simultaneously measured electrocardiography (ECG) and blood oxygen level dependent (BOLD) fMRI to examine the correlation of cerebral cortex and sub-cortex activation and heart rate variability parameters. Correlations were calculated for 11 subjects. Regions of interest (ROIs) were predefined from observations made in previous studies. Lateralization was studied by forming ratios of left and right hemisphere activations in ROIs and calculating correlations of these to heart rate variability (HRV) parameters. Statistically significant correlations were found in every ROI.

論文研討：A combined HRV-fMRI approach to assess cortical control of cardiovagal modulation by motion sickness

論文網址：
A combined HRV-fMRI approach to assess cortical control of cardiovagal modulation by motion sickness

結合 fMRI 與 HRV 研究暈車的心臟迷走神經的調節。

Conf Proc IEEE Eng Med Biol Soc. Author manuscript; available in PMC 2012 Feb 8.
Published in final edited form as:
Conf Proc IEEE Eng Med Biol Soc. 2011 Aug; 2011: 2825–2828.
doi:  10.1109/IEMBS.2011.6090781

A combined HRV-fMRI approach to assess cortical control of cardiovagal modulation by motion sickness

J Kim, V Napadow, B Kuo, and R Barbieri, Senior Member, IEEE

Abstract

Nausea is a commonly occurring symptom typified by epigastric discomfort with the urge to vomit. To date, the brain circuitry underlying the autonomic nervous system response to nausea has not been fully understood. Functional MRI (fMRI), together with a point process adaptive recursive algorithm for computation of the high-frequency (HF) index of heart rate variability (HRV) was combined to evaluate the brain circuitry underlying autonomic nervous system response to nausea. Alone, the point process analysis revealed increasing sympathetic and decreasing parasympathetic response during nausea with significant increased heart rate (HR) and decreased HF. The combined HRV-fMRI analysis demonstrated that the fMRI signal in the medial prefrontal cortex (MPFC) and pregenual anterior cingulate cortex (pgACC), regions of higher cortical functions and emotion showed a negative correlation at the baseline and a positive correlation during nausea. Overall, our findings confirm a sympathovagal shift (toward sympathetic) during nausea, which was related to brain activity in regions associated with emotion and higher cognitive function.

論文研討：Research on Heart Rate Variability (HRV) in Acute Ischemic Stroke

論文網址：
Research on Heart Rate Variability (HRV) in Acute Ischemic Stroke

研究心率變異性（HRV）在急性缺血性腦中風的變化，並使用 CT 與 MRI 來做確認。

《Heilongjiang Medical Journal》 2009-05

Research on Heart Rate Variability (HRV) in Acute Ischemic Stroke

WU Yu-ling (Department of Neurology,Huli Hospital of Xiamen City,Xiamen 361006,China) 

Objective To explore the differential effects of stroke localization on autonomic function parameters assessed by HRV and study the circadian fluctuation of HRV in acute phase of ischemic stroke. Methods 24 h HRV of 70 stroke patients were recorded and analyzed in acute stage (5 d and 5 w) to contract with 50 age-and sex-matched health as control groups. Clinical location of hemispheric brain infarction were verified by CT or MRI. Results (1) In acute phase of ischemic stroke (5 d) all index of heart rate variability had significantly decreased (P0.01),and they all recovered after 5 weeks (P0.05). (2)The index in Patients with right cerebral infarction had significantly lower than that in left localization (P0.05). The index of right insular lobe was the lowest in all groups. Conclusion Acute cerebral infarction significantly decreased heart rate variability as a result of cardiovascular autonomic dysregulation. The decreased autonomic function has reversible tendency following the time went by.

【Key Words】： Cerebral infarction Heart rate variability Autonomic nerve function

論文研討：Heart rate variability and brain imaging of schizophrenic patients

論文研討：MRI Acupuncture Research on Point Specificity

論文網址：
MRI Acupuncture Research on Point Specificity 


New acupuncture research concludes that, “Recent evidence shows that stimulation of different points on the body causes distinct responses in hemodynamic, fMRI and central neural electrophysiological responses.” The researchers note that fMRI and laboratory studies demonstrate unique changes within the body when specific acupuncture points are stimulated. The study demonstrates that specific acupuncture points have specific biophysiological effects. As a result, the researchers suggest further research to investigate these measurable, quantifiable and objective phenomena.

Researchers from the Department of Medicine at the University of California, Irvine, examined the specific effects of needling different acupuncture points as compared with stimulation of non-acupuncture points and placebo simulated stimulation. The researchers note that “... many well-controlled studies do support the principle of point specificity.” They cite as example multiple studies of cardiovascular disease and note that real acupuncture points “elicit(s) significantly greater responses than stimulation of both non-acupoints and inactive acupoints.” They also conclude that stimulation of different acupoints “produces differential input to regions of the brain that regulate sympathetic outflow and cardiovascular function.”

The researchers note that a hemodynamic study of acupoint P6 showed that this acupuncture point “decreased heart rate and increased the high-frequency HRV index of cardiac vagal modulation….” A sham acupoint (a point not located on a traditional acupoint location) was able to decrease the heart rate but did not change the vagal outflow as did P6. These differing mechanisms suggest that sham acupuncture studies may obscure the true medical benefits of acupuncture. In the case of P6 stimulation, only the true acupuncture point increased the high-frequency HRV index. HRV (heart rate variability) is the variance in time interval between heart beats. Reduced HRV is linked to mortality after myocardial infarction and a lowering of HRV is also linked to congestive heart failure, diabetic neuropathy and low survival rates in premature babies. Both true and sham acupuncture decrease heart rates but only true acupuncture increases HRV. Examination of other true acupuncture points (across numerous studies) compared with non-acupuncture points and non-relevant acupuncture points confirms that hemodynamic responses are specific to exact acupuncture points and that true acupoints elicit sympathoexcitatory responses relevant to their traditional medical indications.

Neurological investigations support the specificity of acupuncture points. The researchers examined MRI studies of the brain and note that “stimulation of different sets of acupoints leads to disease-specific neuronal responses, even when acupoints are located within the same spinal segment.” The researchers also note, “The point-specific actions resulting from stimulation of different acupoints in controlled laboratory trials confirm that needling different points on the body produces more than just placebo responses, given that placebo acupuncture is not associated with differential or acupoint-specific responses in anesthetized animals.”

Reference:
 
Point specificity in acupuncture. Chinese Medicine 2012, 7:4 doi:10.1186/1749-8546-7-4. Emma M Choi, Fang Jiang, John C Longhurst.
 
Susan Samueli Center for Integrative Medicine, Department of Medicine, School of Medicine, University of California, Irvine CA.
 
Medical Science, School of Medicine, University of California, Irvine, CA.