In this edition of NA News Drew Smith reports on the positive outcome he has experienced following his deep brain stimulation (DBS) surgery. The videos of him performing various athletic activities are indeed impressive! His situation has also been recently reported in the medical literature (Richard et al, Efficacy of Deep Brain Stimulation in a Patient with Genetically Confirmed Chorea-Acanthocytosis. 2019 May-Aug; 11(2): 199–204).
It is important for everyone affected by neuroacanthocytosis to be aware that the benefits which Drew has experienced are most likely due to a number of specific factors, and may not apply to other people affected by chorea-acanthocytosis or McLeod syndrome.
DBS involves the permanent implantation of electrodes into the brain, which is done through holes in the skull. Leads are tunnelled underneath the skin and connect the electrodes to a battery unit which is typically implanted underneath the skin on the upper chest. Usually, one electrode is implanted on each side of the brain. The hardware is all underneath the skin, and it does not limit people with DBS from showering or swimming. The procedure is normally carried out in 2-3 separate operations. Following the implantation, the system needs to be programmed. This can be a lengthy process and require a number of appointments over a few months to try out different electrical settings in order to determine which are the most beneficial.
DBS has been used in a number of other neurological conditions which result in movement disorders. DBS has been used since the 1990’s for Parkinson’s disease (even though this is a quite different type of movement disorder, where movements are too slow and small); sometimes different brain structures are targeted for different types of movement problems. We are slowly learning, mainly through trial and error, about the other types of neurological (and even psychiatric!) disorders which can benefit from DBS.
Unfortunately, DBS can only help control specific symptoms of NA, and there is no evidence that it changes the underlying brain process. When considering whether DBS will be helpful, we should identify which are the symptoms which are being targeted - DBS can only help the excessive involuntary movements – known as chorea or dystonia. In NA these can affect the face, tongue, trunk, and limbs. If there is benefit, it may be possible to reduce the doses of any medications being taken to control the movements.
While DBS is quite straightforward and relatively low-risk as brain surgery goes, no-one should undergo the DBS implantation unless they can fully understand the risks, and how the process works. It is critical to have realistic expectations of what DBS can and can’t do. If someone has significant problems with thinking and memory and can get confused and disoriented, DBS is not the best thing to do to their brain. The electrodes which are implanted are small, but there is a risk of a small amount of damage being done to the frontal lobes, which can result in a worsening of confusion. Typically, a formal evaluation of thinking and memory (neuropsychological testing) is recommended before someone goes forward with the process.
Another factor to bear in mind is that the symptoms of NA can change with time – and in some cases the involuntary movements go away by themselves. This means that the effects of DBS should be evaluated probably every year, to determine whether it is still helpful. We don’t yet know enough about how long DBS can be beneficial for in NA.
So, in conclusion, I would like to thank Drew for reporting on the exciting positive effects he experienced with DBS - and I hope that he keeps us updated on his progress. For those who are trying to decide whether DBS is right for them, they should discuss it in detail with their neurologist, and make sure they are working with someone who has a lot of experience with this procedure. DBS is not a cure-all, and we are still in the process of learning about its role in managing NA, but it can play a useful role in controlling certain problems with movements