On New Year’s Eve, Hillary Clinton’s doctors announced that the secretary of state has a “blood clot between her brain and skull behind her right ear.” This information is definitely good news, given the various other possibilities at play, though it does raise some questions as well.
From the description, Secretary Clinton has a subdural hematoma, a collection of blood under the dura mater. Our brain is carefully wrapped in three distinct linings: closest to the brain is the pia mater (“tender mother”) which is a delicate Saran wrap-like material that contours to the wiggle and waggle shape of the brain itself. Above this, skullward, is the arachnoid mater (“spidery mother,” also referred to simply as the arachnoid), which is a little bit thicker and less tortuous than the pia. The outermost lining, which sits just under the inside of the skull, is the dura mater (“tough mother”), which lives up to its name as a very tough, almost leathery lining that holds all the goods together tightly. A bleed just under this lining is referred to as a subdural hematoma— imagine the big whopping thigh bruise you got from bumping into that desk, but located just on top of your brain. Click here to visualize just where the brain and skull and the other critical anatomy sit with respect to the clotted blood.
The dura mater is already well known to anyone who has received epidural anesthesia for childbirth—as well as from the recent outbreak of fungal meningitis in persons who had received contaminated epidural steroids prepared by the New England Compounding Center. The epidural space sits just above the dura mater and is a convenient place to deposit small amounts of drug because medication washes away from the area very slowly.
But below the dura mater are small traversing blood vessels that can be disrupted by trauma, such as Secretary Clinton experienced when she fainted, fell, and banged her head. In an earlier piece, I noted that former president Ronald Reagan sustained a subdural hematoma after a horseback riding accident. Subdural hematomas may collect slowly, resulting in subtle symptoms (as happened with Hillary), or more rapidly, requiring emergency surgery to evacuate the clot and stabilize the bleed. The more dangerous bleed related to head trauma is the epidural hematoma, such as baseball pitcher Brandon McCarthy developed earlier this year after being hit by a baseball. He was raced to surgery minutes after the event and still his life was barely saved.
The diagnosis of subdural hematoma makes perfect sense in all regards—except the decision to give blood thinners, which is not standard. The fear is that thinning the blood further might promote more bleeding rather than decrease the risk of clot enlargement. But we will assume that Secretary Clinton is in excellent medical hands and the reasoning behind each decision is sound—though it would be nice if everything would just add up without any dangling facts. The blood thinners make it a possibility that she has superior sagittal sinus thrombosis (which also could be called a clot between the brain and skull) and not a subdural hematoma. (I discussed this in an addendum to my earlier piece).
What’s ahead should be a slow, uneven improvement, but eventual resumption of her previous excellent health. As with any type of concussion, people may string together several excellent days only to find a sudden reversion to headaches and misery just when they thought themselves in the clear. This sort of recovery is frustrating and can wear down a person’s patience—but Hillary Clinton through the years has shown herself to be the most patient of people, weathering countless setbacks, missteps, and uncooperative fates to reemerge again and again in a series of slightly new incarnations, always with the drive and talent that has characterized her from the start.