Hillary Clinton's blood clot in head is serious but treatable

Secretary of State Hillary Rodham Clinton, hospitalized Sunday for a blood clot in her head, is expected to make a full recovery, her doctors said Monday.

Doctors say Clinton, 65, did not suffer a stroke or neurological damage after falling and developing a concussion earlier this month. She was admitted to New York-Presbyterian Hospital.

Clinton's physicians also revealed details about the location and type of blood clot -- factors that affect the seriousness of her condition. The clot is located in a vein in the space between the brain and the skull behind her right ear, according to a statement from her doctors, Lisa Bardack of Mount Kisco Medical Group in New York and Gigi El-Bayoumi of George Washington University in Washington, D.C.

The doctors say they are treating her with blood thinners to help dissolve the clot. They expect her to be released from the hospital after doctors determine the appropriate dose, according to a statement.

Clinton "is making excellent progress and we are confident she will make a full recovery," the doctors said in the statement. "She is in good spirits, engaging with her doctors, her family, and her staff."

Clinton developed the concussion earlier this month after a fall, which occurred when she became faint from dehydration brought about by a stomach bug.

Doctors say they found the clot, called a right transverse sinus venous thrombosis, during a routine follow-up MRI, a scan of the brain.

These kinds of clots are potentially deadly, because they can cause a stroke, hemorrhage or brain swelling, says Geoffrey Manley, a professor at the University of California, San Francisco and chief of neurosurgery at San Francisco General Hospital.

Manley has no personal knowledge of Clinton's case.

But he says this kind of clot forms in "a large draining vein behind the ear, that helps to drain the blood from the brain." Clots block off the outflow of blood from the brain, which can cause blood to back up in the brain.

The pressure of that blood can cause a leak in the vein, causing major bleeding in the skull, Manley says.

The clots can cause headaches, dizziness or changes in consciousness, says Keith Black, a professor and chairman of neurosurgery at Cedars-Sinai Medical Center in Los Angeles. The fact that the clot was found in a "routine" exam -- rather than because it was causing symptoms -- is a good sign, Black says. It suggests that her brain had already found a way to divert blood flow through another vein. Clots that expand to block additional veins -- leading to a buildup of blood -- can be very dangerous.

"Mrs. Clinton is very lucky that this was found just on a routine exam," Black says. "This could have been very serious if it had not been recognized and if the clot had expanded."

Blood thinners can help to prevent the clot from getting any bigger, Manley says.

Doctors have to be careful about administering blood thinners, which can cause bleeding. They typically perform an MRI first, to make sure there is no evidence of bleeding or blood pooling in the skull, says Neil Martin, chair of neurosurgery at Ronald Reagan UCLA Medical Center in Los Angeles.

"With blood thinners, most of these patients do very well," Manley says. "I wouldn't anticipate any long-term complications."

These clots typically form within 24 hours of trauma to the head, Manley says, suggesting that it has been present for weeks.

While these clots aren't common, they are a known complication of head injuries, so doctors typically watch out for them, Manley says. They are more likely to develop if there is a fracture in that part of the skull. Doctors typically put patients with these clots in intensive care. After initial treatment with intravenous anticoagulants, which block clot formation, doctors typically switch to oral medications.

"You want to rapidly thin the blood," Manley says. "It's also important to maintain hydration, because dehydration can contribute to clot formation."

Inactivity, such as Clinton's recent bedrest, also can contribute to blood clots.

This isn't the first time Clinton has suffered a blood clot. In 1998, midway through her husband's second term as president, Clinton was in New York fundraising for the midterm elections when a swollen right foot led her doctor to diagnose a clot in her knee requiring immediate treatment.

Clinton's case underscores the importance of being thoroughly evaluated after any trauma to the head, such as a fall. Such check-ups are especially important if patients have a history of blood clots or an underlying medical issue that makes them more likely to develop clots.

Manley notes that actress Natasha Richardson died in 2009 from a treatable injury after falling in a skiing accident. She refused medical care because she felt well, seeking care only after she developed a headache.

Blood clots such as Clinton's also can cause symptoms such as headaches, Manley says.

Manley says surgeons have limited information about how these clots form and progress, because there hasn't been enough research in the area. He's hoping to help organize a large study with thousands of patients to provide doctors with more guidance.

"This is a huge problem, and we have made zero progress in the course of my career," Manley says.

USA Today