Senator Tim Johnson's Condition

As you have probably already heard, Senator Tim Johnson, Democrat from South Dakota, suffered a neurological injury the other day. He was on a conference call with reporters when he started stuttering and having trouble forming words. He was later admitted to the hospital and had emergency surgery. Details from the operation are now available via the NY Times...

Birth Defect Led to Stroke in Senator, Doctors Say

By LAWRENCE K. ALTMAN

Senator Tim Johnson suffered an unusual form of stroke, one due to bleeding into his brain from an abnormality present from birth, according to a statement from Adm. John F. Eisold, the attending physician of the Capitol, and interviews with neurological experts.

Mr. Johnson, 59, is in an intensive care unit at George Washington University Hospital after undergoing emergency surgery for the stroke late Wednesday. He is being heavily sedated to rest his brain, a standard treatment after such surgery.

Mr. Johnson, a Democrat from South Dakota, is expected to be in intensive care for several days — also standard — while doctors determine if any brain damage occurred that would affect movement or intellectual ability. Admiral Eisold and experts not involved in Mr. Johnson’s case said it was too early to tell how well he might recover.

Admiral Eisold and Mr. Johnson’s family have not said where in the brain the bleeding occurred or how large the hemorrhage was, and they have not disclosed other factors that could be important in determining the seriousness of his illness. For example, it is not known whether doctors had previously detected the malformation in Mr. Johnson’s brain.

One expert, Dr. David J. Langer of Manhattan, said that the type of stroke and the speed with which the doctors operated offered a guarded prognosis.

“The fact that he had emergency surgery after an event during the day suggests that he had bleeding that was life-threatening,” said Dr. Langer, who directs cerebro-vascular neurosurgery at St. Luke’s-Roosevelt, Beth Israel and Long Island College Hospital. “You don’t just take the blood out to take it out, you only take it out when a life is threatened,” he said, “and that means he was deteriorating in his level of consciousness. There would be no other reason for an emergency operation.”

Dr. Langer said that if Mr. Johnson’s condition was deteriorating rapidly, doctors most likely did not have time to obtain critical details from a magnetic resonance imaging scan and probably operated after performing a CT X-ray scan. In general, malformations of the sort that caused Mr. Johnson’s stroke are best detected on M.R.I.’s.

In such circumstances, Dr. Langer said, neurosurgeons often cannot determine the cause of the bleeding until they operate.

Dr. David S. Liebeskind, associate director of the University of California, Los Angeles, Stroke Center said that surgery for arteriovenous malformations can be as complex as any involving the brain.

In Mr. Johnson’s favor, said Dr. Liebeskind, is that “it sounds like they caught this problem fairly early” and “could intervene before further damage occurred.”

But he and other experts said that Mr. Johnson’s prognosis would depend in part on what doctors observe as they monitor and test him over the next few days.

Standard care would involve seeking evidence of swelling of his brain and signs of further bleeding as well as preventing seizures. The doctors will monitor Mr. Johnson’s heart function in part because such strokes can put great stress on the body.

The doctors are expected to lighten the sedation after a few days to look for damage.

Dr. Lee H. Schwamm, director of acute stroke care at Massachusetts General Hospital in Boston, said that initial findings may not reflect a patient’s long-term outcome.

Patients with mild neurological disabilities usually recover well. But patients with serious disabilities do not necessarily have a bad outcome and can recover significantly.

Studies have shown that fewer than 0.5 percent of people have arteriovenous malformations and that some forms of them are hereditary.

The malformations are characterized by a direct connection between arteries and veins. Normally, blood vessels known as capillaries serve as the connections.

Although the malformations are present from birth, it often takes years for the pressure to build to the point of rupturing.

Doctors have been detecting arteriovenous malformations more frequently since the introduction of CT and M.R.I. scans beginning in the mid-1970’s. Before then, doctors had no way to detect such malformations until they bled.

The malformations are sometimes found on scans among patients who receive them after complaining of headaches and nonspecific symptoms. But many such incidentally detected malformations are small, leaving doctors uncertain whether and how to treat them. This is among the reasons that Dr. Jay P. Mohr at Columbia University is leading a federally sponsored study to determine among other things whether it is better to operate early or to watch and wait.