Psychosurgery for stuttering

Dear editor

We read with interest the article entitled “Anterior capsulotomy improves persistent developmental stuttering with a psychiatric disorder: a case report and literature review” published in Neuropsychiatric Disease and Treatment.¹ The authors report on a 28-year-old man with persistent developmental stuttering who was treated by bilateral anterior capsulotomy in the People’s Republic of China. To our knowledge, this is a new and previously unreported application of this technique for this indication. Accordingly, as the authors highlight, “the evidence for surgical treatment of persistent developmental stuttering and associated psychiatric disorders is limited”, placing their approach within the clinical research forum. In this experimental context, this case report brings forward several important reflections on patient evaluation, technique utilized, and postoperative follow-up.

The authors fail to indicate the patient’s maternal language. Given that the team is Chinese, we can assume that it was Mandarin; however, the most widely used variety of Chinese spoken in Sichuan is Sichuanese, which is the lingua franca in Sichuan, Chongqing, and part of Tibet. Either way, for the neuropsychological evaluation scales, it is surprising that the authors refer to articles that have validated these scales in English but not in Chinese. It would have been important for the authors to evaluate the patient’s personality before and after the intervention.

Concerning the surgical technique, it is unfortunate that no computed tomography scan was performed to correct for the inherent deformations associated with magnetic resonance imaging (MRI), especially when it is a high-field coregistered 3T MRI. The authors mention that a “test stimulation generated by the Elekta neurostimulator at both high frequency (130 Hz) and low frequency (5 Hz) was then carried out to verify the target of the electrode”, but they do not indicate the clinical signs that were sought or obtained during stimulation. It is unfortunate that we have no information on the quality of verbal fluency during high and low frequency stimulation. It would have been pertinent for the authors to include the voltage utilized during stimulation. We are not informed whether or not a speech therapist was present perioperatively during this evaluation.

Furthermore, one must question whether a lesional technique was appropriate in this case. The authors’ motivation for selecting a bilateral anterior capsulotomy over medical therapy or deep brain stimulation (DBS) was because “both the patient and his family opted for capsulotomy for financial reasons”. It would be interesting to know the reasons justifying the bias of burdening the patient with the cost of this supposed biomedical research protocol. Also, when the research is unpublished and founded on weak scientific evidence, a prudent approach is warranted so as to offer the technique associated with minimum risk and maximal benefits. In a research context where, like the authors remind us, “the evidence for surgical treatment of persistent developmental stuttering and associated psychiatric disorders is limited”, a DBS technique seems justified given that its effects are, contrary to lesional techniques, both reversible and adjustable. From a scientific standpoint, this technique provides the advantage of completing double-blind evaluations and excludes any potential placebo effect contributing to observed improvements. DBS would also have allowed us to verify with which plot and parameters the therapeutic effect was obtained, so as to better understand the underlying pathophysiological mechanisms. Finally, DBS would have permitted electrical recording for several days before connecting the neurostimulator.

The progress made in functional neurosurgery and the emergence of DBS offer an important hope for cure in patients suffering from medically refractory psychiatric illness. We must remain very vigilant regarding the methodology of these studies so that psychosurgery does not, once again, become a matter of controversy in such a way that it compromises its development.