Rom Houben, a 46 year old Belgian man, made headlines around the world earlier this week when it came to light that he had been mistakenly diagnosed as being in a persistent vegetative state since a car accident 23 years ago. Houben, who is severely paralyzed, appears to be entirely cognitively aware, and is now communicating with his family and with journalists through a keyboard, his hand movements aided by a therapist.

Most of the media attention, sparked by an article in the German magazine Der Spiegel, has focused on Houben’s haunting messages describing his decades-long imprisonment. But neurologist Steven Laureys, who first noticed signs of consciousness in Houben three years ago, hopes the case will bring attention to a broader plight–the lack of research and care for people diagnosed as being in a vegetative or minimally conscious state. TR highlighted some of Laureys research in a 2007 feature, Raising Consciousness.

(These disorders, called disorders of consciousness, are often mistakenly referred to as coma. However, comas typically last just days or weeks–after that, patients either wake up or transition into a vegetative state, those totally unaware of their environment, or a minimally conscious state, in which patients may occasionally laugh or cry, reach for objects, or even respond to simple questions.)

The revelation of Houben’s state of mind was determined from a number of medical tests, but one of the most striking was a type of brain imaging called positron emission scanning (PET). According to this test, which measures brain metabolism, Houben’s brain looked entirely normal. “Now we can measure the brain’s activity with more and more detail,” says Laureys. “And we see a big contrast between what we see at the bedside and what we see in functional neuroimaging.”

While PET scanning technology has been available for decades, it is only just starting to be applied to patients like Houben. That’s thanks in part to a lack of research funding for this field, as well as the enormous technical obstacles of performing brain imaging on patients who often cannot move or comply with directions. Laureys and a handful of scientist around the world are now studying whether PET scans and other brain imaging methods, such as functional MRI, an indirect measure of brain activity, can help more accurately diagnose such patients.

While Rom Houben’s case is an extreme example–very few patients are likely to be as cognitively intact–Laureys says that in some ways, it is not that unusual. According to a study he published earlier this year, as many as 40 percent of patients diagnosed as vegetative are in fact minimally conscious. “He is very exceptional in the sense that he was fully conscious,” says Laureys. “But he is unfortunately not that exceptional in that he showed clear signs of awareness,” such as following a moving mirror with his eyes. Laureys says that this case and others demonstrate the need to use standardized methods of assessing patients, and to assess them multiple times, since cognitive function can vary widely day to day.