Other experts questioned the method that Houben was apparently using to communicate. The technique is known as "facilitated communication," in which the patient supposedly directs the hand of a speech therapist who typed out his thoughts.
Houben's doctors said it seemed to be genuine. Until now.
Dr. Steven Laureys, a neurologist at Liege University Hospital in Belgium, one of Houben's doctors, now acknowledges the technique doesn't work and that while Houben is conscious, he is not communicating.
"We did not have all the facts before," he said Friday. "The story of Rom is about the diagnosis of consciousness, not communication."
Houben was injured in a car crash in 1983 when he was 20, and was said to be in a vegetative state, in which a patient is unconscious and there is no evidence of perception or intentional movement.
Based on bedside tests four years ago, Laureys and his team diagnosed Houben as being conscious, and performed brain scans proving his brain activity was more active than other doctors had thought.
Laureys, who was not Houben's treating physician, said the man's family and other doctors brought in a speech therapist to use facilitated communication. "From the start, I did not prescribe this technique," he said. "But it is important not to make judgments. His family and caregivers acted out of love and compassion."
Last November, news of the case first broke in Der Spiegel, a German publication, and The Associated Press and others reported on it as well. Houben's speech therapist claimed she could feel pressure from his hand guiding her on a keyboard. A basic test was performed that ostensibly proved it was Houben who was communicating.
Since then, Laureys has done his own small study of three speech therapists working with minimally conscious patients, including Houben. In two of those cases, including Houben's, the technique failed. Last week, Laureys presented the results at a neuropsychiatry meeting in London.
"To me, it's enough to say this method doesn't work," he said Friday.
Other experts said the technique should never have been used in the first place.
"It's like using an Ouija board," Arthur Caplan, a professor of bioethics at the University of Pennsylvania, said Friday. "It was too good to be true and we shouldn't have believed it."
Last year, Houben's mother claimed her son was writing a book. "Just imagine," Houben ostensibly typed out via his speech therapist. "You hear, see, feel and think but no one can see that."
Tom McMillan, a professor of neuropsychology at the University of Glasgow, said facilitated communication could be used with some patients but should not be used with ones like Houben who had severe brain injuries. "It has an intermediary who can exert control and affect the outcome," he said.
Experts say the larger question of whether people like Houben who have a traumatic brain injury are conscious and alert remains unanswered. Earlier this month, Laureys and others reported finding glimmers of awareness in some apparently vegetative brain-injury patients. (Houben was excluded from that study).
"I hope Rom and his family will stay as an example" of how hard it is to pick up the signs of consciousness, Laureys said. "Even when we know that patients are conscious, we don't know if there is pain or suffering or what they are feeling."
(This version CORRECTS Corrects headlines and lede to say man was in vegetative state, not coma.)