Diaphragmatic Breathing and Heart Rate Variability Training for Improving Hypertension in Fragile X Associated Tremor/Ataxia

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).

Inclusion Criteria:

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.

Exclusion Criteria:

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