(Published by Giacino et al in 2012 in New England Journal of Medicine)
(Written by Dr Lucia M. Li)
After a serious traumatic brain injury, a small proportion of patients are left in abnormal conscious states, such as a vegetative state or a minimally conscious state. Patients in a vegetative state may appear to be awake and have their eyes open, but do not respond to the world around them. Patients in a minimally conscious state have some response to the world around them, for example, may react when close family members say their name.
Amantadine is a drug originally developed to treat flu, but it has also been used to treat certain aspects of Parkinson’s disease. After a brain injury, the activity of certain chemicals in the brain is reduced and this is thought to contribute to many these abnormal conscious states. Amantadine is thought to increase the action of these chemicals in the brain, so could be a potential treatment in this group of patients.
This study set to investigate whether amantadine could improve the disability level of patients in a vegetative or minimally conscious state.
This study recruited 184 patients soon after their brain injury (4-16 weeks). Each patient was randomly assigned to one of two groups – one group received 4 weeks’ of treatment with amantadine and the other group got 4 weeks of treatment with a placebo drug. Their disability level was measured every week for 6 weeks – this means each patient had 4 measurements whilst taking amantadine or placebo, and 2 measurements afterwards.
Both groups of patients showed recovery (lower disability scores) over time. The group taking amantadine recovered more quickly than the group taking placebo. By the end of 4 weeks of treatment, the group taking amantadine had lower disability scores than the group taking placebo. However, in the 2 weeks after treatment finished, the group taking placebo recovered more quickly. By the end of 6 weeks (4 weeks treatment followed by 2 weeks off treatment), the placebo group and amantadine group had similar disability scores. There was no difference between vegetative state patients and minimally conscious patients in how they responded to the drug.
These results show that amantadine can increase the rate of recovery in patients in a vegetative or minimally conscious states. However, this benefit was only observed whilst taking the drug.
This study also raises some questions for future research. Patients only took the drug for a very short period of time, so we still do not know what the effects would be from taking this drug for a long period of time. Patients were only in the study for 6 weeks in total, so we do not know anything about whether the drug has any long-term effects on recovery. In this study, patients received standard rehabilitation therapies on top of amantadine/placebo. It would be useful to investigate how much of the recovery in the amantadine group was due to amantadine alone or in combination with the other standard therapies. Finally, future studies should explore some of the practical aspects of using amantadine e.g. the optimal dose, when best to start using it and how long to use it for, to achieve maximum benefit.
(Written by Dr Lucia M. Li)
After a serious traumatic brain injury, a small proportion of patients are left in abnormal conscious states, such as a vegetative state or a minimally conscious state. Patients in a vegetative state may appear to be awake and have their eyes open, but do not respond to the world around them. Patients in a minimally conscious state have some response to the world around them, for example, may react when close family members say their name.
Amantadine is a drug originally developed to treat flu, but it has also been used to treat certain aspects of Parkinson’s disease. After a brain injury, the activity of certain chemicals in the brain is reduced and this is thought to contribute to many these abnormal conscious states. Amantadine is thought to increase the action of these chemicals in the brain, so could be a potential treatment in this group of patients.
This study set to investigate whether amantadine could improve the disability level of patients in a vegetative or minimally conscious state.
This study recruited 184 patients soon after their brain injury (4-16 weeks). Each patient was randomly assigned to one of two groups – one group received 4 weeks’ of treatment with amantadine and the other group got 4 weeks of treatment with a placebo drug. Their disability level was measured every week for 6 weeks – this means each patient had 4 measurements whilst taking amantadine or placebo, and 2 measurements afterwards.
Both groups of patients showed recovery (lower disability scores) over time. The group taking amantadine recovered more quickly than the group taking placebo. By the end of 4 weeks of treatment, the group taking amantadine had lower disability scores than the group taking placebo. However, in the 2 weeks after treatment finished, the group taking placebo recovered more quickly. By the end of 6 weeks (4 weeks treatment followed by 2 weeks off treatment), the placebo group and amantadine group had similar disability scores. There was no difference between vegetative state patients and minimally conscious patients in how they responded to the drug.
These results show that amantadine can increase the rate of recovery in patients in a vegetative or minimally conscious states. However, this benefit was only observed whilst taking the drug.
This study also raises some questions for future research. Patients only took the drug for a very short period of time, so we still do not know what the effects would be from taking this drug for a long period of time. Patients were only in the study for 6 weeks in total, so we do not know anything about whether the drug has any long-term effects on recovery. In this study, patients received standard rehabilitation therapies on top of amantadine/placebo. It would be useful to investigate how much of the recovery in the amantadine group was due to amantadine alone or in combination with the other standard therapies. Finally, future studies should explore some of the practical aspects of using amantadine e.g. the optimal dose, when best to start using it and how long to use it for, to achieve maximum benefit.