A stroke affecting the right side of the brain can lead a person to be visually unaware of what's happening on the left.
A little brain stimulation seems to speed up recovery from a stroke.
This isn't the sort of brain stimulation you get from conversation. It's done using an electromagnetic coil placed against the scalp.
Researchers think the treatment encourages brain cells to form new connections, allowing the brain to rewire itself to compensate for damage caused by a stroke.
The latest evidence that stimulation works comes from Italy, where researchers treated patients with a condition called hemispatial neglect. It's a common problem in stroke patients that leaves them unable to see or recognize anything on one side of their body, even though their eyes work just fine.
Scientists suspect the problem occurs when a stroke causes damage that upsets the normal balance between the two sides of the brain. A stroke in the right side of the brain, for example, often seems to cause the healthy left side of the brain to become overactive and overload circuits involved in perception.
A team from the Santa Lucia Foundation in Rome thought electromagnetic stimulation might help restore normal levels of activity in the affected side of the brain. So they did a study of 20 stroke patients with hemispatial neglect.
Some got 10 sessions of magnetic stimulation. The rest got a sham treatment.
After two weeks, the ones who got stimulation improved 22 percent on tests of perception on the affected side, the team reported in the journal Neurology. There was no change among those who got the sham treatment.
The study is "an important step forward," says Randolph Marshall, a stroke specialist at Columbia University Medical Center. "This work fits with other work suggesting that magnetic stimulation can enhance neuroplasticity."
Previous studies have found that brain stimulation can help stroke patients recover motor skills, muscle strength and the ability to swallow. Even so, magnetic stimulation remains largely experimental and isn't yet a typical treatment for stroke patients.