THURSDAY, Jan. 19 (HealthDay News) -- Up to 30 percent of stroke patients develop delirium shortly after hospitalization and these patients fare worse than those without delirium, a new study finds.

Canadian researchers reviewed 10 studies that included more than 2,000 patients who were hospitalized after suffering either an ischemic (caused by blood vessel blockage) or hemorrhagic (bleeding) stroke.

In most of the studies, 10 percent to 28 percent of the patients experienced delirium, an acute state of confusion that includes disorientation, attention deficit, altered and fluctuating mental status, and sometimes hallucinations. In one study, 48 percent of patients experienced delirium.

Compared to patients without delirium, those who experienced delirium were 4.7 times more likely to die in the hospital or within a year of hospitalization, three times more likely to be discharged to a long-term care facility, and they stayed in the hospital nine days longer.

In general, stroke patients who experience delirium are older, have more medical problems and suffer more severe strokes, which might explain why stroke patients with delirium do worse than others.

The study appears Jan. 19 in the journal Stroke.

Delirium in stroke patients can be caused by other problems such as medicines, infection, substance abuse, metabolic abnormalities, and renal or heart failure.

Recognizing the underlying problems that cause delirium in stroke patients might help improve their prognosis, study senior author Dr. Gustavo Saposnik, director of the Stroke Outcomes Research Center at St. Michael's Hospital in Toronto, said in a journal news release.

More information

The Royal Society of Psychiatrists in the U.K. has more about delirium.