Dear Editor,

The experience of Escobar Vidarte et al. [1] contributes significantly to foster the application of posterior hypothalamic region (pHyp) deep brain stimulation (DBS) for the treatment of patients with aggressive attitude and intellectual disability due to the reported efficacy in a large sample size with congruous follow-up up to 10 years. A recent revision of our experience of 7 patients treated by pHyp DBS for aggressive disorder and intellectual disability, operated on between 2002 and 2010 [2], allowed moving some consideration with a longer follow-up period. Four patients presented with a mean follow-up of 15 years (12–17 years) and a mean improvement at OAS [3] of 82.5%. Two patients out of 4 had a 90% and 100% improvement with a follow-up of 15 and 12 years, respectively. Nevertheless, DBS batteries, respectively, run out 10 years and 6 years after surgery. Battery replacement was not performed, and improvement due to DBS did not fade, without drug adaptation, up to now. This original experience can be unfolded either by the nature of the disorder, on which other factors such as familial and social events can have a substantial modifier role, and the possible plastic changes induced by the continuous diencephalic stimulation [4]. In light of this observation, a temporary use of DBS can also be envisaged in this population. Another patient had a 70% improvement at OAS, until 2019, when she started to have a severe recurrence of her obsessive-compulsive disorder, coupled to a slight worsening of the aggressive attitude. For that reason, lithium and third-generation antipsychotic drug (which was not yet diffusely prescribed when she had surgery in 2006) allowed to have a massive improvement of obsessive-compulsive disorder and aggression (90%), with the stimulation switched off since then. Third-generation antipsychotics represent a precious add-on also to the treatment of aggressive outbursts [5], which can be used in combination with DBS or limiting pHyp stimulation to more severe cases.

We also owe to admit that we recorded a high number of lost to follow-up patients (3 out of 7). This can be explained, other than the lack of efficacy (1 patient), by the length and the organization of the follow-up. In particular, after surgery patients were followed up in psychiatry territorial units far from our institution and telephone contacts resulted ineffective in 2 patients. Our experience highlights the need to an advanced integration between functional neurosurgeons and psychiatrists, so that, as suggested by Escobar Vidarte et al. [1], pHyp DBS “may be included in a strong therapeutic treatment strategy for this group of patients, typically isolated to mental institutions to allow them to reintegrate into society.”

Michele Rizzi, Vincenzo Levi, and Nicolò Castelli recently served as paid consultants for WISE Srl, a manufacturer of electrodes used for intraoperative neurophysiological monitoring. The other authors have no conflicts of interest to declare.

This work was supported by the Italian Ministry of Health (RRC).

Martina Giordano, Niccolò Innocenti, Vittoria Cojazzi, and Nicolò Castelli: acquisition, analysis, and interpretation of data. Michele Rizzi and Vincenzo Levi: drafting the work. Giuseppe Messina and Vittoria Nazzi: critical revision and final approval of the version.

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.