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Valsalva's
type of breathing
These are patients with Rett
syndrome who try to forcefully breathe out after their glottises
have closed off the upper airways. The end-result is an increase
of pressure in the lungs and the chest. The increased thoracic
pressure reduces blood flowing back into the heart and consequently
excites the brainstem very violently. There are very large
swings in the levels of cardiac vagal tone and baroreflex
sensitivity. The NeuroScope™ measures these two brainstem functions
simultaneously and in real-time. There are large changes in
blood pressure too. Some patients in this category may perform
Valsalva's type of breathing consecutively for a long time.
Medical consequences are: Unsteadiness with wondering eyeballs
due to dizziness. There may be transient changes in consciousness.
Some patients may just stare into the abyss briefly. All these
can be mistaken for seizure attacks. There are periodic changes
in the electroencephalogram (EEG) coinciding with the severe
drops in blood pressure in some of the Rett girls. This can
be mistaken for abnormal changes in the EEG due to seizure
disorders. Some of these patients may also exhaust their brainstems
and enter into Brainstem Shutdown (the skin turns white and
the body becomes floppy). This category of breathing does
not respond to drug treatment and we are still looking for
ways of influencing Valsalva's type of breathing in Rett syndrome.
(Click
here to see a Rett girl performing Valsalva's type of breathing).
This
graph was recorded using the NeuroScope™ system
Click
here to see the graph of Valsalva's type of breathing
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