There are conflicting reports regarding Yasser Arafat's health. Though some Palestinian officials have been quoted as saying the longtime PLO leader is already dead, the French doctors tending to Arafat insist he's still alive, albeit in a "deeper coma" than the one he was in a few days ago. How does one measure the depth of a coma?
In the case of an acutely ill patient such as Arafat, with the Glasgow Coma Scale, created in 1974 by the Scottish neurosurgeons Graham Teasdale and Bryan Jennett. At the time, physicians had no reliable way of classifying a coma's severity, a task complicated by the fact that a patient's condition may appear to improve or deteriorate on a daily, even hourly, basis. A nurse who witnesses some reflexive limb movement in the morning may judge a patient's coma light, while the doctor who sees a motionless body in the afternoon may opine that it's deep.
Teasdale and Jennett came up with a simple, less subjective test to gauge a coma's depth. The GCS takes into consideration three factors: a patient's ability to open his eyes, verbal response, and physical movement. Points are awarded in each category, with a score of one equaling "no response." The most weight is given to the physical-movement part of the test; if the patient can follow commands to move, then they receive six points. A perfect score—that is, what wide-awake adults register—is 15; three is the lowest possible score, indicative of the deepest coma. A score anywhere between three and five hints that the patient suffers from acute brain injury, and that even if he recovers, there will probably be lasting damage.
Coma patients who score low on the GCS can make miraculous recoveries, but the odds are against them. Eighty-seven percent of those who score a three or four after a full day in a coma will either die or remain in a persistent vegetative state. Of patients who receive scores of five to seven, a little over half will never regain consciousness.
The GCS is used primarily for diagnosis in acute cases—that is, in intensive care units or wherever else the gravely ill might be found immediately after falling into a coma. In rehabilitative settings, by contrast, where long-term coma patients are often taken, the more popular measurement of coma depth is the Rancho Los Amigos Scale. This scale consists of eight levels, with a score of one indicating that the patient does not to react to any stimuli, and an eight meaning the patient has recovered not only their consciousness, but their memory and social skills as well.