Correspondence (reply): In Reply

We thank our correspondents for their contributions, and we welcome the wide ranging approval as well as the suggestions made by some of them.

We agree with Timmann that stereotactic lesional surgery on subcortical brain regions, which in some centers is considered even now for therapy resistant psychiatric disorders (1), has yielded results that are taken into consideration when selecting a target structure for deep brain stimulation (DBS). Procedures such as anterior capsulotomy or cingulotomy have had positive effects for treatment resistant psychiatric disorders in selected patients. However, because of their destructiveness and the associated range of possible adverse effects, these procedures have not become widely accepted. They did, on the other hand, contribute to the question of whether the less invasive, potentially reversible procedure that is DBS, if used on similar anatomical structures, might minimize the previous risks and disadvantages of a surgical procedure.

We agree with Professor Meyer that it is absolutely essential that all side effects are recorded with the utmost care and in every detail in the comparatively recent research subject that is DBS in the psychiatric setting. Uncritical use prompted by the euphoria triggered by initial positive results is dangerous for the procedure itself and for the patients who are to receive DBS in the future. In this context, we wish to point out a research project into the ethical, social, and legal aspects of DBS, which is focusing on the balance of risks and benefits of the procedure and is thus also trying to find an answer to the question of whether DBS patients may develop possible personality changes (2).

Undoubtedly, initial promising results from the treatment of psychiatric patients with DBS will need to be confirmed by international multicenter studies under controlled conditions (3).

We are pleased to take up Dr Rave-Schwank’s suggestion of the book “Tief im Hirn [deep in the brain]” by Professor Dr H Dubiel. This book plays an important part in patients’ perceptions. Professor Dubiel describes, among others, his subjective experience of postoperative depression after having stimulation electrodes inserted into the subthalamic nucleus to treat his Parkinson’s disease. This serious postoperative complication is thankfully rare or transient. However, we feel the need to point out that deep brain stimulation resulted in good motor effects in Professor Dubiel, and he has actually announced at several lectures that even if being fully aware of his own disease process he would have repeated surgery if he needed to.

We also wish to note explicitly that, although the procedure in question is deep brain stimulation, its use in Parkinson’s patients is not analogous to its use in patients with therapy resistant psychiatric disorders.