Treating patients early for so-called mini-strokes could dramatically cut the risk of a follow-up major stroke, report two studies in The Lancet and The Lancet Neurology.

Researchers from Britain and France found that patients treated within 24 hours of having a mini-stroke cut their chances by an astonishing 80 per cent of having a more serious stroke in the next 90 days.

The researchers say their findings suggest that mini-strokes should be taken much more seriously and considered as warning signs that other larger strokes could be on their way.

Mini-strokes have the same symptoms of a major stroke, causing numbness, slurred speech, paralysis on one side of the body, or a sudden headache. But the symptoms last less than a day, which is why they are called transient ischemic strokes.

Most follow-up strokes happen within 30 days of a smaller one, but many patients often do not get treatment -- such as prescriptions for blood thinners and cholesterol-lowering drugs -- for weeks.

In The Lancet study, Dr. Peter Rothwell of Oxford University led a team that looked at 1,278 patients who had a stroke or a mini-stroke. The patients were drawn from a larger study group of nearly 100,000 people from the Oxford Vascular Study.

The team found 591 patients who had mini-strokes. In the first part of the study, 310 of the mini-stroke patients received standard care under British medical guidelines. That meant they were referred to an outpatient clinic within three days and then, after a wait of 20 days, they were typically prescribed drugs, including aspirin, to lower their blood pressure and cholesterol, and to prevent clotting.

In the second part of the study, about 281 other patients were given these same medications within 24 hours of their suspected mini-stroke. The researchers found that:

  • Patients treated immediately had only about a 2.1 per cent chance of having a major stroke in the next three months.
  • Patients who weren't treated as quickly had about a 10.3 per cent chance of having a major stroke in the next three months.

The age or gender of the patients didn't affect the patients' stroke risk and early treatment did not increase the risk of bleeding or other complications.

Two Canadian doctors, Dr Naeem Dean, Royal Alexandra Hospital in Edmonton, and Dr Ashfaq Shuaib of the University of Alberta, say the findings "are very important and should promote renewed attention to urgent care of patients with TIAs and minor strokes."

Similar research was published in The Lancet Neurology. Dr. Pierre Amarenco of Bichat-Claude Bernard University Hospital in Paris and colleagues set up a 24-hour clinic to treat patients with suspected mini-strokes.

Among the 1,085 patients followed, the chance that patients would have another stroke within 90 days was 1.24 per cent. That compares to a predicted stroke rate of nearly 5.9 per cent based on historical medical data. Thus, the study showed that immediate treatment reduced the risk of recurrence of TIA by almost 80 per cent.

The study authors note that because almost three-quarters of patients were discharged from the clinic on the same day as diagnosis, their clinic is also likely to involve lower costs and greater patient satisfaction than treatment without such a clinic.

The British Stroke Association said Rothwell's study should lead to faster treatment of mini-strokes.

"This research is of the utmost importance. It clearly shows that thousands of people could be saved from life shattering strokes every year, simply by making sure that everyone who has a transient ischemic attack (TIA) or minor stroke gets currently available treatment quickly," the agency said in a statement.

"It is not about a brand new technology, or a costly intervention. It is about organizing our services so that a TIA or minor stroke is always treated, and treated urgently."