The burden of normality: from 'chronically ill' to 'symptom free'. New ethical challenges for deep brain stimulation postoperative treatment.

Although an invasive medical intervention, Deep Brain Stimulation (DBS) has been regarded as an efficient and safe treatment of Parkinson's disease for the last 20 years. In terms of clinical ethics, it is worth asking whether the use of DBS may have unanticipated negative effects similar to those associated with other types of psychosurgery. Clinical studies of epileptic patients who have undergone an anterior temporal lobectomy have identified a range of side effects and complications in a number of domains: psychological, behavioural, affective and social. In many cases, patients express difficulty adjusting from being chronically ill to their new status as 'treated' or 'seizure free'. This postoperative response adjustment has been described in the literature on epilepsy as the 'Burden of Normality' (BoN) syndrome. Most of the discussion about DBS postoperative changes to self is focused on abnormal side effects caused by the intervention (ie, hypersexuality, hypomania, etc). By contrast, relatively little attention is paid to the idea that successfully 'treated' individuals might experience difficulties in adjusting to becoming 'normal'. The purpose of this paper is (1) to articulate the postoperative DBS psychosocial adjustment process in terms of the BoN syndrome, (2) to address whether the BoN syndrome illustrates that DBS treatment poses a threat to the patient's identity, and (3) to examine whether the current framework for rehabilitation after DBS procedures should be updated and take into account the BoN syndrome as a postoperative self-change response.