The test devised at the Royal Hospital for Neurodisability in London looked at 13 patients who came out of a persistent vegetative state (PVS). Now the therapy team hopes to publish guidance on the programme for the benefit of other hospitals.
The technique, known as Smart (Sensory Modality Assessment and Rehabilitation Tool), could help make it clear when treatment should not be withdrawn and can also tell doctors the right time to apply concentrated stimulation that might bring the patient out of a coma. At present, courts are asked to rule on whether a PVS patient kept alive by artificial feeding should be allowed to die. Medical guidelines say that doctors can apply to a court to have a patient's food and hydration withdrawn after 12 months.
The test involves systematically stimulating each of seven "modalities" - sight, hearing, touch, smell, taste, movement and communication - while looking for signs of returning awareness. Hearing, for instance, can be stimulated by ringing a bell behind the patient. Responses are graded from one (no response) to five (discriminatory response) which is classified as emergence from PVS. Responses can include reflex actions like blinking, withdrawing from a repeated stimulus, or showing awareness of a direction a stimulus is coming from.
A total of 30 patients were investigated using Smart. The researchers found that seven patients emerged during the study and a further six patients emerged over the next two years. The six all had scores that improved threefold or more in at least one area.
Dr Sarah Wilson, from the University of Surrey at Guildford, who will present the team's findings at the British Psychological Society's London conference today said: "People coming out [of PVS] produced a change score of at least three, while those with a change score of two or less didn't come out. It's the first time we have been able to separate the outcome groups as cleanly as this."
Looking for such a level improvement could provide an early warning of when a patient was likely to emerge from a PVS. However, she stressed that a low change score did not necessarily mean a patient was never going to recover.