Clinton’s Venous Sinus Thrombosis
What is a transverse sinus venous thrombosis?
In 2012, then Secretary of State Hilary Clinton became dehydrated and fell down, suffering a concussion. Weeks later she was hospitalized for what was described at the time as a “blood clot.” We weren’t told where the clot was at the time. After several days in the hospital, she was discharged home.
She was later seen to be wearing glasses with a Fresnel prism in them, a common treatment for double vision. Double vision is a not uncommon transient development in concussions. It may also develop from a blood clot on or in the brain.
Yesterday, it was revealed that Secretary Clinton had, in fact, suffered from a transverse sinus venous thrombosis and was treated with blood thinners, which she is apparently still receiving.
As a leading candidate for the Presidency, Secretary Clinton’s health is a public concern. So what, exactly, is a transverse sinus venous thrombosis?
This is easiest if we think of a sinus as a large vein. Specifically, the transverse sinus is one of the major draining veins of the brain. It is located at the back of the head, extending from the midline to a point behind each ear (there is one on each side of the head). Just behind each ear, the transverse sinus makes an ‘S’ turn down into the neck, where it becomes the internal jugular vein. The internal jugular vein is THE major vein draining the brain of blood. Again, it is a paired structure with one on each side.
If we think of the internal jugular vein as a river draining blood from the brain back to the heart, then the transverse sinus is one of the major tributaries of that river. Each transverse sinus carries some percentage of the blood exiting the brain and returning to the heart. What percentage? Hard to say, since the exact size and anatomy of the transverse sinuses vary in different individuals. In many folks, probably most, the transverse sinus is larger on one side or the other. Such a dominant sinus may drain more than 50% of the blood returning from the head. Likewise, a small, nondominant sinus might drain considerably less than 50% (most of the remainder being drained by the opposite transverse sinus).
A venous thrombosis is a clot. A clot in a nondominant transverse sinus might be relatively benign. Of course, a clot in the dominant sinus is more likely to cause serious trouble. It should be noted that venous sinus thrombosis is a relatively common syndrome and that a nondominant sinus is more likely to clot than a dominant sinus.
There are several causes of venous thrombosis, one major cause being dehydration. Secretary Clinton was dehydrated, which likely lead to her clot. Nothing earth shattering there.
How significant is such a clot? It could be very significant, but probably not in this case. In a worst case scenario, such a clot leads to sludging of the blood and engorgement of the brain as the blood backs up. Think of water backing up behind a cofferdam, the difference being that the brain exists in a closed space. Engorgement of the brain (with blood, CSF, or edema fluid) will eventually raise the pressure inside the head (see my article Brain Squeeze here). Increased pressure inside the head can make a person very sick, or worse.
So how is venous thrombosis treated? For starters, with avoidance of dehydration. Second, if the clot is nonocclusive (that is, only partially occludes the sinus) and thus the sinus is still functional (blood is able to get through), then the goal is to prevent further clotting in the short run (this is probably why she was hospitalized for several days, to monitor her and prevent further clotting) and to passively dissolve the clot in the long run (with good hydration and blood thinners over months). Such patients may have a headache, and sometimes double vision, at the onset. Full recovery without a stroke is the rule.
If the clot is occlusive and no blood is getting through, the blood backs up faster, causing severe congestion of the brain and, if unchecked, a stroke. This situation warrants very aggressive treatment, requiring an ICU stay and multiple angiograms with administration of medications directly into the clot to actively dissolve it.
It does not appear that Secretary Clinton has had a stroke.
Overall, her transverse sinus venous thrombosis appears to have been a relatively minor affair, one that was treated quickly and appropriately and without significant sequelae. In this physician writer’s opinion, it should not be a consideration in her run for the Presidency, nor will it impact her decision making skills.