VOLUME 26, ISSUE 3 • SEPTEMBER 2022 Full issue »

New Guideline on Invasive Therapies in the Treatment of Parkinson's Disease

There is already a long history of European guidelines for Parkinson’s disease jointly elaborated between the organization of European Neurologists, the European Academy of Neurology (formerly the EFNS/ENS) and the European Section of MDS. The first was published in 2006 and the second in 2013. Guidelines are to summarize current evidenced-based knowledge and guide future research. Given the huge progress in the field, the two organizations decided to make a revision.

The enterprise started with invasive therapies, but the further aspect of PD therapy will follow. This guideline is very particular, as the GRADE system was used for the first time to objectively assess the evidence, which made this work more complex and demanding. Of note, this methodology was previously used for PD only for the NICE-GL. Additionally, Cochrane response — one of the institutions most experienced in developing systematic reviews — was engaged to reach the high methodological standard.

As opposed to all previous guidelines, we covered the whole spectrum of invasive therapies. Therefore, we decided to divide the invasive therapies into:

lesional therapies, including radiofrequency thermocoagulation, radiosurgery with gamma radiation, magnetic resonance imaging–guided focused ultrasound lesioning
nonlesional therapies, namely DBS and pump therapies

We have developed two research questions based on PICO methodology. Those questions have been answered with eight recommendations and five clinical consensus statements. The following recommendations have been proposed. STN-DBS is undoubtably one of the best-studied interventions for advanced PD with fluctuations, which are not satisfactorily controlled with oral medications. Similarly, evidence suggests that GPi-DBS can also be applied. For early PD with early fluctuations, STN-DBS is likely to improve motor symptoms and can be offered. However, DBS should not be offered to people with early PD without fluctuations. LCIG and an apomorphine pump can be considered for advanced PD with fluctuations not sufficiently managed with oral treatments. Unilateral MRgFUS of the STN can be considered for distinctly unilateral PD within registries. Unilateral Pallidotomy is a treatment for advanced PD with fluctuations if safer therapies are not available.

For other, mostly lesional therapies we were able to establish clinical consensus for the following statements: Radiosurgery with gamma radiation cannot be recommended, unilateral radiofrequency thermocoagulation of the thalamus for resistant tremor can be recommended if other options are not available, unilateral MRgFUS of the thalamus for medication-resistant tremor of PD can be considered only within registries, and unilateral MRgFUS of the pallidum is not recommended.

Evidence for invasive therapies in PD is heterogeneous. Unfortunately, only some of these therapies have a strong scientific basis. Importantly, invasive therapies are reserved for specific patient groups, mostly in the advanced stage of Parkinson's disease. Those therapeutic options should be provided by experienced PD centers. We hope that this new, complex approach to guideline development will serve PD specialists and consequently help to offer the best quality treatment to the PD patients.

Our guideline was simultaneously published in two journals of the above mentioned societies: Movement Disorders journal and European Journal of Neurology.