Delhi: Focused ultrasound subthalamotomy in one hemisphere helped in improving motor features of Parkinson's disease in selected patients with asymmetric signs, finds a recent study in the New England Journal of Medicine. However, it was associated with adverse events including dyskinesia, weakness on the treated side, and speech and gait disturbances.
Focused ultrasound thalamotomy has been approved by the Food and Drug Administration to treat essential and parkinsonian tremors.
The preferred neurosurgical target for deep-brain stimulation to treat cardinal motor features of Parkinson's disease is the subthalamic nucleus. Focused ultrasound is an imaging-guided method for creating therapeutic lesions in deep-brain structures, including the subthalamic nucleus.
The study included 40 patients with markedly asymmetric Parkinson's disease who had motor signs not fully controlled by medication or who were ineligible for deep-brain stimulation surgery. They were assigned in a 2:1 ratio to undergo focused ultrasound subthalamotomy on the side opposite their main motor signs (n=27) or a sham procedure (n=13).
The primary efficacy outcome was the between-group difference in the change from baseline to 4 months in the Movement Disorder Society–Unified Parkinson's Disease Rating Scale (MDS-UPDRS) motor score (i.e., part III) for the more affected body side (range, 0 to 44, with higher scores indicating worse parkinsonism) in the off-medication state. The primary safety outcome (procedure-related complications) was assessed at 4 months.
Key findings of the study include:
The mean MDS-UPDRS III score for the more affected side decreased from 19.9 at baseline to 9.9 at 4 months in the active-treatment group and from 18.7 to 17.1 in the control group the between-group difference was 8.1 points.
Adverse events in the active-treatment group were dyskinesia in the off-medication state in 6 patients and in the on-medication state in 6, which persisted in 3 and 1, respectively, at 4 months; weakness on the treated side in 5 patients, which persisted in 2 at 4 months; speech disturbance in 15 patients, which persisted in 3 at 4 months; facial weakness in 3 patients, which persisted in 1 at 4 months; and gait disturbance in 13 patients, which persisted in 2 at 4 months.
In 6 patients in the active-treatment group, some of these deficits were present at 12 months
"Longer-term and larger trials are needed to determine the role of focused ultrasound subthalamotomy in the management of Parkinson's disease and its effect as compared with other available treatments, including deep-brain stimulation," concluded the authors.
The study, "Randomized Trial of Focused Ultrasound Subthalamotomy for Parkinson's Disease," is published in the New England Journal of Medicine.
DOI: 10.1056/NEJMoa2016311