for people ages 50-90 (full criteria)
healthy people welcome
at UC Davis
study started
estimated completion



To study whether heart rate variability training and respiratory coherence can improve hypertension in individuals with FXTAS. All patients will receive HRV biofeedback training for 20 sessions. Our hypothesis is that individuals with FXTAS who undergo 20 sessions of biofeedback training will improve self-regulatory skills for reducing hypertension, as measured by blood pressure measurement to below 140/90. The investigators hypothesize that individuals who successfully develop increased heart rate variability and better synchrony between heart rhythm and respiration will show the greatest improvements in self-regulatory skills for hypertension.


Fragile X-associated tremor ataxia syndrome (FXTAS) is a late onset neurodegenerative disease that affects carriers of the fragile X premutation. This project proposes the evaluation of an innovative intervention program that promotes self-regulatory skills for hypertension in individuals with FXTAS. Using a control-group experimental design, the investigators propose to explore the efficacy of a biofeedback treatment to support self-regulatory processes on the physiological level: Heart Rate Variability (HRV) and respiratory coherence biofeedback.

Chronic hypertension contributes to cardiovascular complications, dementia, and increased risk of stroke. Our results indicate that the risk of hypertension is significantly elevated in male premutation carriers with FXTAS compared with carriers without FXTAS and controls.

Several research studies showed high levels of physiological arousal in individuals with Fragile X-Associated Disorders (FXS/FX-AD), related to a dysregulation of the sympathetic and parasympathetic nervous system. One parameter to measure physiological arousal is cardiovascular activity. It provides an index of parasympathetic and sympathetic involvement of the autonomic nervous system. Heart rate is under the control of efferent sympathetic and vagal activities directed to the sinus node, which are modulated by central brain stem (vasomotor and respiratory centers) and peripheral oscillators (oscillation in arterial pressure and respiratory movements). Spectral analysis of heart rate variability (HRV) is a reliable quantitative method for analyzing the modulatory effects of neural mechanisms on the sinus node.

Biofeedback treatments are reported for over 30 years. Biofeedback provides specific information about internal biological processes (i.e. muscle activity, respiration, heart rate variability, skin temperature and brain electrical activity) in an individual. In general, by enhancing the awareness of these processes and training to volitional control over them, specific parameters can be improved. The internal biological processes can be measured with a specific biofeedback equipment that convert this data into signals, often in the form of auditory, visual or somatosensory events, so that the individual can perceive real-time changes in their physiological activity. As the individual learns to control these events, healthier physiological processes are conditioned. Depending upon the physiological processes targeted, healthier patterns of activity can be achieved by most people after they have participated in 10 to 50 sessions of biofeedback supported with professional coaching and practice. Various biofeedback protocols and assistive electronic technologies such as the NeXus-10, emWave Personal Stress Reliever® or StressEraser® exist to enhance the balance of parasympathetic activity, vagal tone, increase HRV and synchronize respiration with the heart rhythm (i.e., the slowing down and speeding up of the heart over time).


Hypertension FXTAS HRV and respiratory coherence biofeedback FXTAS-affected FXTAS-unaffected


You can join if…

Open to people ages 50-90

  1. Males and females between the ages of 50-90 with a molecular documentation of a fragile X premutation, diagnosed with FXTAS.
  2. stable current pharmacological treatment regimen for at least 4 weeks.
  3. English speaking (the intervention is currently only available in English)
  4. Clinically significant hypertension.
  5. Normal or corrected to normal vision and hearing.

You CAN'T join if...

  1. Significant medical and behavioral problems that would interfere with the study (e.g. not being able to sit and play a computer game for 10 minutes)
  2. Participants who plan to initiate or change pharmacologic or non-pharmacologic interventions during the course of the study
  3. Individual is non-verbal (has no spoken language)
  4. English is not the primary language.
  5. Clinically critical Hypertension that requires medical attention


  • University of California, Davis, MIND Institute accepting new patients
    Sacramento California 95817 United States


accepting new patients
Start Date
Completion Date
University of California, Davis
Phase 3
Study Type
Last Updated