Doctors in Amsterdam say that a drug usually associated with drowsiness has given a severely brain-injured man brief periods of lucidity. In a recent case report, they describe how a single dose of the drug zolpidem—more familiarly known by the brand name Ambien—can temporarily restore the man’s ability to talk and walk. Sadly, the effects last only about two hours, but the man’s case may provide insight into how the brain can be damaged by strokes and other trauma.
According to the case report, published in the journal Cortex last month, the 37-year-old man had suffered a tragic brain injury at age 29. He had choked on a piece of meat, which cut off oxygen to his brain long enough that it caused severe, lasting damage to his neurological function. Though he showed some recovery initially and retained a level of awareness, he soon stopped being able to move independently, talk, or stay awake for very long. For the next eight years, the man’s condition remained the same, and he needed round-the-clock nursing care and a feeding tube to stay alive.
While zolpidem is most often used as a sedative, evidence has been building that it can sometimes have a paradoxical effect, causing alertness in some people, including those with certain neurological disorders that leave them in a coma-like state. Doctors decided to give the man a single, relatively high dose of the drug. Within 20 minutes, he became able to talk. He then spoke to his father over the phone for the first time in years, and, with some assistance, even managed to walk again. He did have amnesia of the choking incident and the three years before it, as well as some hearing problems, but otherwise, he was cheerful and alert, even asking for fast food at one point.
Unfortunately, the miracle recovery only lasted about an hour before he gradually returned to his baseline level of function. When he was given repeat doses of zolpidem throughout the day, the periods of normalcy grew more short-lasting each time, until the drug stopped working at all and even had a sedative effect on him. Eventually, doctors figured out that the zolpidem was most effective—lasting about 30 to 60 minutes per dose before fading away over the next hour—when he hadn’t taken it in the previous two to three weeks. Because of this, he now receives the drug only for special occasions, such as family visits or dental appointments.
Despite the elusiveness of a long-term cure for the man’s condition, his doctors still wanted to understand exactly how zolpidem was capable of causing such an amazing, if brief, turnaround. So they studied his brain, via EEG and MRI, before and after he took the drug. Their findings suggest that zolpidem, which works by boosting the effect of a key inhibitory neurotransmitter called GABA, is quieting down parts of the man’s brain that became overactive post-injury, while also increasing levels of brain wave activity linked to alertness.
“If you could compare the function of the brain, as it were, to a large string orchestra. In our patient, the first violins play so loud that they drown out the other members of the string orchestra and people can no longer hear each other. Zolpidem ensures that these first violins play more ‘pianissimo,’ so that everyone plays back within time,” lead author Hisse Arnts, a medical resident and neuroscience researcher at the VU University Medical Center Amsterdam, told IFLScience.
Because this is only a single patient, and reports of zolpidem restoring awareness in similar patients are rare, there’s still a lot left to be learned about the drug’s effects on the brain outside of its accepted use as a sleep aid. But ideally, this research could lead to advances in understanding and perhaps one day repairing the unique sort of brain damage that’s responsible for the man’s condition. One possible future step, the authors speculated, is to use existing therapies like deep brain stimulation to balance out the brain’s overactivity for longer periods of time than zolpidem is capable of doing.