According to a new study published in the Neurorehabilitation and Neural Repair journal, people who suffer a stroke have a two-week window to achieve optimum recovery.

The findings result from a study in London and Adelaide that followed the recovery of 60 patients for up to a year following a stroke.

The study revealed, for the first time, that the capacity for the human brain to recover and rewire itself peaks at about two weeks after a stroke and reduces over time.

Lead author Dr Brenton Hordacre, from the University of South Australia, says the multi-site study showed conclusive evidence that the brain only has a small window of opportunity to more easily repair itself after stroke.

"Earlier animal studies suggested this was the case, but this is the first time we have conclusively demonstrated this phenomenon exists in humans," Dr Hordacre says.

Researchers scanned the brains of stroke survivors as they recovered over 12 months and found that in the initial days following an ischemic stroke, the brain has a greater capacity to modify its neural connections, and its plasticity is increased.

"It is during this early period after a stroke that any physiotherapy is going to be most effective because the brain is more responsive to treatment."

The researchers used continuous transcranial magnetic stimulation (cTBS) to repetitively activate different motor cortex hemispheres to measure brain plasticity.

The Adelaide laboratory tested the stroke damaged motor cortex, the main area that controls movement, while the London laboratory tested the non-stroke damaged hemisphere.

"Our assessments showed that plasticity was strongest around two weeks after stroke in the non-damaged motor cortex. Contrary to what we expected, there was no change in the damaged hemisphere in response to cTBS."

Dr Hordacre says the findings confirm the importance of initiating therapy as soon as possible after a stroke.

Current evidence indicates that less than eight minutes of daily therapy is dedicated to upper limb recovery within the first four weeks of a stroke.

"Delivering more treatment within this brief window is needed to help people recover after a stroke.

"The next step is to identify techniques which prolong or even re-open a period of increased brain plasticity, so we can maximise recovery," says Dr Hordacre.

Senior physiotherapist Dirk Schoombee says the sooner a person begins stroke rehabilitation, the more likely they are to regain lost abilities and skills. But gains can still be made many months later.

"The rate of recovery is generally greatest in the days, weeks and months following a stroke.

“Patients who receive early rehab will have better outcomes at three months, experience fewer complications and have better quality of life by 12 months.

"However, the good news is, there is significant evidence of improvement even 12 to 18 months after a stroke."