By Eleanor McDermid, medwireNews Reporter
medwireNews: Focused ultrasound ablation (FUSA) of the globus pallidus internus improved symptoms in a substantial proportion of people with Parkinson’s disease in a randomised trial, but it comes with side effects.
The treatment consisted of FUSA targeted to the globus pallidus internus contralateral to either the patient’s dominant side or the side with the greatest motor impairment.
In total, 65 of the patients who underwent FUSA and 22 who underwent a sham procedure completed the 3-month follow-up. During this time, 69% versus 32% of these groups met the criteria for a response, report Howard Eisenberg (University of Maryland, Baltimore, USA) and colleagues in The New England Journal of Medicine.
A response was regarded as an improvement in off-treatment motor impairment and/or on-treatment dyskinesias, specifically at least a 3-point improvement in off-medication Movement Disorders Society–Unified Parkinson’s Disease Rating Scale III for the treated side and in on-treatment Unified Dyskinesia Rating Scale, respectively.
In the active-treatment group, 29% had a response in motor symptoms only, 12% in dyskinesias only and 28% in both. In the sham group, 27% had a response in motor symptoms only and 5% in both motor symptoms and dyskinesia, with no participant recording an improvement in dyskinesias only.
Among 53 actively treated patients assessed after 12 months, 70% had a response. This included seven who had not had a response at month 3.
The most common treatment-related adverse events were dysarthria, gait disturbance and loss of taste, which each occurred in two patients. These were mostly mild and transient, but one patient had moderate dysarthria that persisted at the 1-year follow-up.
In a linked editorial, Anette Schrag (University College London, UK) says that “it is worth emphasizing that despite an incisionless procedure, FUSA of the globus pallidus internus is not risk-free.”
She also points out that “the degree of improvement was less than suggested by previous open-label studies”, that “not all patients derived a meaningful benefit from the intervention” and that only a third had improvements in both motor function and dyskinesias.
Schrag concludes: “The results of this trial are promising, but given the nonreversible nature of the intervention and the progressive nature of the disease, it will be important to establish whether improvements in motor complications are maintained over longer periods and whether treatment results in improved overall functioning and quality of life for patients.”
News stories are provided by medwireNews, which is an independent medical news service provided by Springer Healthcare Ltd. © 2023 Springer Healthcare Ltd, part of the Springer Nature Group
N Engl J Med 2023; 388: 683–693
N Engl J Med 2023; 388: 759–760