A 51-year-old woman who was left paralysed and unable to communicate following a massive stroke has written for the first time in seven years, scientists say.
The Israeli patient, who was diagnosed with "locked-in syndrome", typed an emotional email to her six children using a revolutionary device that is controlled by sniffing.
The woman was so badly brain-damaged by the stroke that she cannot move any of her limbs or even blink in response to simple questions. She wrote the letter within a few days of being taught how to use the device.
The technology, developed by scientists at the Weizmann Institute in Rehovot, Israel, is now being used by other severely disabled people to surf the internet and even control a wheelchair. One, a 63-year-old quadriplegic woman who can barely speak, wrote her first letter in 10 years with the device and has started using it to send emails.
"The most moving thing has been witnessing this technology give people a means of communication when they haven't had it," said Noam Sobel, a neurobiologist at the institute, who helped develop the technology.
The device works by detecting slight changes in pressure that are produced when a person opens or closes their soft palate, the tissue at the roof of the mouth that controls air flow through the nose. Many patients with serious disabilities are still able to move their palate voluntarily, and so can use the device, said Sobel.
When the sensor is connected to a computer, a person wearing the device can use sniffs alone to select letters on the screen and build up words, phrases and sentences.
One patient, a 42-year-old man who was diagnosed with locked-in syndrome after a car crash 18 years ago, used the sniff-controlled device to say he preferred it to a previous disability aid that performed a similar function by tracking his eye movement, writing that it was "more comfortable and more easy to use".
The speed at which patients can write with the new device varies between around 20 seconds and a minute for a single letter of the alphabet. The 1997 book, The Diving Bell and the Butterfly, was written by Jean-Dominique Bauby at a rate of roughly one word every two minutes. Bauby, who became locked-in after suffering a stroke, selected letters by blinking his left eye.
In another test of the device, a 30-year-old man who was paralysed from the neck down in a car accident six years ago, used the device to steer a motorised wheelchair along a winding path 30 metres long. After one trial attempt, the patient completed the course as fast as healthy volunteers.
Sobel said he was anxious what locked-in patients might write after being unable to move or communicate for so long, but he said none wrote about wanting to end their own lives. "I was afraid that the minute we could communicate, all that might come out," he said. "What's important is giving the person the ability to express themselves."
The findings are published in the latest issue of the Proceedings of the National Academy of Sciences.
