The pathophysiology of primary exertional headache (EH) is unknown. Physical exertion is associated with Valsalva-like manoeuvres (VM). VM leads to increased intrathoracic pressure and reduces cerebral venous drainage. Internal jugular vein valve incompetence (IJVVI) leads to retrograde venous flow during VM with transient increase of intracranial pressure. We analysed the prevalence of IJVVI in EH patients using duplex ultrasound. Bilateral measurements were performed at rest and during VM in 20 patients and 40 controls. Incompetence was concluded if retrograde venous flow could be seen in the jugular Doppler spectrum during repeated VM. Seventy percent of EH patients and 20% of controls demonstrated IJVVI, yielding a significant difference (P = 0.0004). IJVVI was always observed on the dominant venous drainage side. Our study suggests that intracranial venous congestion caused by retrograde jugular venous flow might play a role in the pathophysiology of EH with IJVVI as a risk factor.
IJVVI = internal jugular vein valve incompetence
Before CCSVI treatment, we have a form of IJVVI in which the valve leaflets are fixed. Flow cannot go forward easily so it finds alternate collateral routes out and/or is slowed down.
After CCSVI treatment, if the valves were ballooned, we might have a form of IJVVI in which the valve leaflets are no longer present so blood flow can at certain times of 'transient increased pressure' flow backwards from the heart through the jugular vein. The most obvious example of transient increased pressure is when having a bowel movement. As soon as pressure normalizes, it flows forward again.
We know from other research that, although very rare, having the after-CCSVI-treatment type of internal jugular vein valve insufficiency increases the small risk of having classic soap opera amnesia.
From this research, we know that the after-CCSVI-treatment type of internal jugular vein valve insufficiency increases the risk of a headache upon exertion.
There is also a link to idiopathic intracranial hypertension with the after-CCSVI treatment type of insufficiency.
These links actually support the idea that CCSVI is unhealthy, since these far lesser and transient forms of reflux can cause such issues as amnesia, IIH and headache. But it also means that you do not want a healthy vein valve ballooned, if anyone present happens to have a healthy IJV vein valve.
We've covered all this before, but it never hurts to cover it again.