A remarkable new case study tells the story of how a man who was unable to walk or talk was temporarily “woken up” after being given a sleeping tablet.
Reporting in the journal Cortex, researchers at Radboud University Medical Center (UMC) and Amsterdam UMC in the Netherlands hope the case study can help improve our understanding of the complex neurophysiological processes that are seen after severe brain injuries. It also provides new evidence that the insomnia drug Zolpidem, aka Ambien, could be used to help people in a locked-in or vegetative state.
Eight years ago, a 29-year-old man known only as Richard suffered from severe oxygen deprivation after choking on a piece of meat. Although he initially showed signs of recovery, the patient eventually lost the ability to talk, eat independently, or move spontaneously as a result of his brain injury. However, despite appearing “shut off” in certain aspects, he appeared to be awake and conscious.
"His condition is actually called akinetic mutism, a fairly rare clinical picture," Dr Hisse Arnts, lead study author and neurosurgical resident at Amsterdam UMC, told IFLScience. "These patients have an intact level of consciousness but present with the inability to speak or move spontaneously. The patient constantly is in a wakeful state of profound apathy, seemingly indifferent to pain, thirst, hunger, and shows no emotions."
Now aged 37, his condition had remained stable with no signs of improvement until his doctors and family grasped at an experimental treatment. Willemijn van Erp, a specialist in elderly care at the Radboud UMC, had read about numerous case studies that suggested a common insomnia drug could have a positive effect on patients suffering from disorders of consciousness. With the blessing of his family, Richard was given the drug.
Zolpidem is a sleeping pill sometimes sold under the name Ambien in the US that has been prescribed to millions of people around the world with insomnia. The drug has become fairly infamous for its occasionally bizarre side effects, such as problems with memory loss and unusual changes in behavior, but at its core it suppresses certain brain activity, allowing the person to fall asleep.
According to the case study, within 20 minutes of receiving the drug, Richard started talking spontaneously. Van Erp had given Richard a single dose of Zolpidem but had to promptly leave to attend another patient. Unexpectedly, she was called by a nurse who said she had a "special person" on the phone: it was Richard asking her what was going on and if he could order some fast food.
"The patient had a real awakening," confirmed Dr Arnts.
He even managed to walk a short distance and phone his father, who had not heard his son's voice for years. He remained in this state for over 30 minutes before returning to his usual condition. The team gave Richard a dose of the drug on multiple occasions and he reacted in a similarly positive way each time with periods of activity lasting up to 2 hours. However, the team eventually noted "a severe reduction in effectiveness" after he had received the drug for several consecutive days. It appeared the drug's effect began to fade if it was taken too frequently.
To understand how the drug had this effect, researchers scanned Richard's brain before and after receiving the drug. The brain scans showed overactivity in certain parts of the brain, which the sleeping was able to suppress, creating space for speech and movement.
"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," Dr Arnts explained to IFLScience. "That’s really the beautiful part of our study, and these credits also go to my colleagues Lennard Boon and Conrado Bosman."
A number of other cases have shown Zolpidem has a “miraculous” ability to temporarily arouse people from disorders of consciousness. The first was reported in 1999 with a patient in South Africa who fell into a vegetative state for three years after being hit by a truck. Upon receiving a single dose of Zolpidem, he awoke with the ability to speak for a few hours. As time passed and he received more doses, his cognition improved and he was eventually able to remain awake without Zolpidem. A number of other similar cases have since been reported in other parts of the world.
A 2017 systematic review looked at whether Zolpidem can treat conditions of consciousness (other than insomnia), but concluded more research is needed. Nevertheless, as this case study demonstrates, this drug holds potential in the further study and treatment of some neurological disorders.