How to address one of the paradoxes of DBS: “a distressed mind in a repaired body”? The challenges of personhood and identity
The effect of DBS on the motor symptoms of essential tremor and Parkinson’s is well established. However, the effect of DBS on cognition and behaviour in motor disorders is less well established. There have been observations of depression and even suicide in patients with Parkinson’s after DBS surgery. These observations are somewhat perplexing since such side effects are not what one would expect in patients with improved motor symptoms. Cognitive decline or psychiatric comorbidity may also accompany the natural course of Parkinson’s disease. However, when such conditions appear or reappear after DBS implantation, the question may be asked: Is this the result of the natural progression of Parkinson’s? Or is this an effect of DBS?
Deep brain stimulation is an approved and effective neurosurgical intervention for motor disorders such as Parkinson’s disorder and essential tremor. It is an experimental procedure for the treatment of a number of psychiatric conditions, namely treatment refractory depression. In Parkinson’s disease, DBS alleviates some of the symptoms of the disorders and may improve the quality of life in daily tasks, but does not cure. It is an invasive and expensive procedure usually used as a last resort treatment, when medication and all other treatments have failed.
These uncertainties about factors that contribute to occurrences of behavioural, cognitive and psychiatric complications after DBS may impede a full risk assessment of the procedure and create challenges for the selection of patients and the management of their expectations.
There have also been observations of patients facing social adaptation challenges after DBS surgery. Difficulties in accepting the fact that they have lost years of their lives to illness or in living with their new selves have been reported. One study showed that 65% of married patients who had undergone surgery experienced a conjugal crisis after DBS (Agid et al, 2006) and another one demonstrated that 33% of spouses had depression following their partner’s surgery (Schupbach et al, 2006).
This goes to show how mixed the success of DBS can be. Little attention has been devoted to these issues. Yet they are not negligible and even less so if DBS is extended to neuropsychiatric disorders where serious consequences may be anticipated in the psychosocial adjustment of patients over the long term. That is why, it becomes urgent “(…) to more systematically characterize cognitive and behavioural changes after DBS and its social impacts” (Bell, 2009: 584).
This text summarises the ethical issues related to deep brain stimulation, developed and discussed in an excellent publication by Emily Bell, Ghislaine Mathieu and Eric Racine. (2009). Preparing the ethical future of deep brain stimulation. Surgical Neurology, 72: 577-586. The summary has been approved by the first author.
|Adapted by :||Myriam Hivon, Ph.D.|
Bell E, Mathieu G, Racine E (2009). Preparing the ethical future of deep brain stimulation. Surgical Neurology, 72: 577-586.
Agid Y, Schupbach M, Gargiulo M, et al. (2006). Neurosurgery in Parkinson’s disease: the doctor is happy, the patient less so? J Neural Transm Suppl. 70: 409-14.
Schupbach M, Gargiulo M, Welter ML, et al. (2006) Neurosurgery in Parkinson disease: a distressed mind in a repaired body? Neurology 66:1811-6.