Brain MRI

I feel strongly that the almost 90% PFO incidence in CFS is largely acquired with the onset of CFS and is not pre-existing except in perhaps 27%. The PFO shunt from right to left will be stronger however, once CFS cardiac physiology is manifest with the near universal (>96%) finding of diastolic dysfunction. I suspect the frequent brain UBO’s on MRI scans are likely a result of this right to left PFO shunting as well as certain symptoms such as migraine and periodic hyperventilation. PFO could also be a factor in sleep apnea pathophysiology. Heavy snoring and airway obstruction is a valsalva maneuver and can cause shunting right to left, particulary if there is also desaturation. Below is an abstract of data on CFS patients at the Cheney Clinic showing an extremely high incidence of PFO using contrast bubble studies.