Article Text

Download PDFPDF

Behavioural disorders, Parkinson's disease, and subthalamic stimulation
  1. R G Brown
  1. Department of Psychology, Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, UK; r.brown{at}

    Statistics from

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

    Stimulation of the bilateral subthalamic nucleus can have adverse consequences

    The paper by Houeto et al1 in this issue (pp 701–707) offers new evidence to suggest that bilateral subthalamic nucleus (STN) stimulation can have adverse and potentially serious consequences for patients and their families, despite the benefits obtained in motor function. The study has important implications for those running surgical programmes in terms of patient selection, preoperative counselling, and postoperative care.

    The management of the motor symptoms of Parkinson's disease has been greatly enhanced in recent years by new approaches to functional neurosurgery, both stereotactic lesions to the globus pallidus or subthalamic nucleus and stimulation of the same structures via chronically implanted electrodes. These treatments can achieve remarkable clinical outcomes in some patients and significant improvement in many, particularly in the control of levodopa induced dyskinesia. Although research has also investigated the impact of surgery on cognition,2 the psychiatric and the broader social consequences have been largely ignored.

    The paper reports data on a series of 24 patients, all of who were judged clinically to have benefited from surgery. As in most surgical programmes, patients with dementia or with significant psychiatric problems were excluded as part of normal preoperative clinical screening. Social adjustment was assessed using a standardised instrument 3–38 weeks after surgery and revealed that, although just over a third showed evidence of good to excellent adjustment, moderate or severe impairment was found in the remainder affecting broad aspects of social and interpersonal functioning. Psychiatric problems were also common postoperatively, particularly anxiety disorders. Five patients became depressed after surgery and one patient committing suicide despite having shown dramatic improvement in motor function.

    Such results offer some important lessons. One key finding was the high level of prior psychopathology in the sample. Such problems were either not reported by patients during screening (possibly for fear that it would lead to exclusion) or were not given sufficient priority in the clinical decision making process. The postoperative exacerbation of these problems and their impact on social adjustment suggest that great care needs to be taken in identifying prior psychiatric disorder, and not just current problems. Although a psychiatric history need not be a cause of exclusion, it should indicate the clear need for enhanced postoperative follow up and care in at risk patients.

    The paper also offers some important anecdotal reports on the cases of social maladjustment. The deterioration of marital and family relations points to the importance of psychosocial factors in the postoperative period. For example, the sudden breakdown in patterns of dependency and caregiving built up over years can have a marked impact on interpersonal relationships. Similar adverse responses, including suicide, have been reported after other dramatically life enhancing surgical procedures such as sight restoration,3 and have long been recognised in the field of organ transplantation.4 Such responses point to the need for careful counselling of patients with Parkinson's disease and their families before surgery to help prepare them for the possible impact on their lives, both positive and negative.

    Stimulation of the bilateral subthalamic nucleus can have adverse consequences