Present and future of subthalamotomy in the management of Parkinson´s disease: a systematic review

ABSTRACT

Introduction: The subthalamic nucleus (STN) is known to be involved in the pathophysiology of Parkinson´s disease and by reducing its abnormal activity, normal output of basal ganglia can be restored along with improvement in PD cardinal motor features. Deep brain stimulation of the STN is currently the main surgical procedure for PD with motor complications, but lesioning can be an alternative.

Areas covered: Here, the authors systematically review the current evidence regarding subthalamotomy both with radiofrequency and, more recently, with focused ultrasound (FUS) for the treatment of PD.

Expert opinion: Unilateral subthalamotomy for the treatment of PD motor features can be considered a viable option in asymmetric patients, particularly with FUS which allows a minimally invasive safe and effective ablation of the STN. Risk of inducing dyskinesia (i.e., hemichorea/ballism) may be strikingly reduced when lesions enlarge dorsally to impinge on pallidothalamic fibers.

KEYWORDS:

• Basal ganglia
• functional neurosurgery
• Parkinson´s disease
• subthalamotomy
• subthalamic nucleus
• focused ultrasound
• dyskinesia
• radiofrequency

Article highlights

• The subthalamic nucleus (STN) plays a key role in the pathophysiology of Parkinson´s disease (PD).

• Neurosurgical targeting of the STN with Deep Brain Stimulation is a worldwide procedure for PD.

• Ablation of the STN with Radio Frequency has also been undertaken in several hundred of patients.

• Recent introduction of focal ablation of brain targets with ultrasound (FUS) as an incisionless, less invasive procedure has opened new horizons.

• FUS ablation of the STN has been carried out with good results and a double-blind randomized study showed significant benefit and low incidence of permanent severe side effects.

• The fear to produce persistent, troublesome hemichorea-ballism by STN lesioning is not supported by data but better target definition is needed to optimize therapeutic efficacy.

• Subthalamotomy (by FUS) could be considered as a early treatment strategy in the future.

Declaration of interest

J Máñez-Miró reports personal fees from BIAL, personal fees from ZAMBON, personal fees from INSIGHTEC, grants from ABBVIE, personal fees from ITALFARMACO, outside the submitted work.

J Obeso reports personal fees from Focused ultrasound foundation, personal fees from Insightec, personal fees from BIAL, personal fees from ZAMBON, personal fees from BOSTON SCIENTIFIC and personal fees from BIOGEN, outside the submitted work. R Rodriguez-Rojas reports personal fees from INSIGHTEC, outside the submitted work. R Martínez-Fernández reports personal fees from Focused ultrasound foundation, personal fees from Insightec, personal fees from BIAL, personal fees from ZAMBON, personal fees from BOSTON SCIENTIFIC and personal fees from BIOGEN, outside the submitted work. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or conflict with the subject matter or materials discussed in this manuscript apart from those disclosed.

Reviewer disclosures

A reviewer on this manuscript has previously advised J Obeso about different methodological issues related to the clinical trials (with focused ultrasound) he and his team are conducting in Parkinson disease. The reviewer is not directly involved in these trials or their results. Peer reviewers on this manuscript have no other relevant financial relationships or otherwise to disclose.

Additional information

Funding

This paper was not funded.