Focused ultrasound subthalamotomy revealed improvement in Parkinson’s patients

1. In patients suffering from Parkinson’s disease displaying signs of motor dysfunction even after receiving treatment, this randomized control trial revealed improvement in motor features, such as tremor and rigidity, following focused ultrasound subthalamotomy when compared to those that received a sham procedure.

2. This trial displayed adverse events in the active treatment group with head pain, dizziness, and head-tilting being the most reported. The sham procedure displayed head pain, headache, and high blood pressure as the most common.

Evidence Rating Level: 2 (Good)

Study Rundown: Parkinson’s disease has been long treated with various medical treatment options for patients, however, motor and tremor complications still seize to exist. One of the current treatment options is deep-brain stimulation, nevertheless, not all patients are eligible for this procedure. This study examined the potential use of magnetic resonance-guided focused ultrasound subthalamotomy as it does not require any invasive procedures, such as craniotomy, as part of the process where patients were randomized into the active treatment group where the procedure is performed or the sham procedure group. Patients were recruited into the study if they displayed signs of severe asymmetric parkinsonism, were unsuitable for surgery or had refused invasive treatment options. The study revealed improvement of motor function in patients with Parkinson’s after receiving the focused ultrasound subthalamotomy, but adverse results such as head pain were also noted in this treatment group.

This was a well-designed study with a high-power calculation as measured by Student’s t-test. However, it was limited by a small sample size and the patients were mainly recruited from one site, therefore it is unclear if the results can be generalized to the larger patient population. In order to learn whether the focused ultrasound subthalamotomy can be effective in the management of Parkinson’s disease, larger trials with a longer-term will need to be conducted.

Click to read the study in NEJM

Relevant Reading: Effects of Motor Symptom Laterality on Clinical Manifestations and Quality of Life in Parkinson’s Disease

In-Depth [randomized controlled trial]: This prospective study successfully enrolled a total of 40 patients into a double-blind randomized trial, that had highly asymmetric parkinsonism at the time of screening. An informed consent was obtained prior to enrolling the participant in the trial. The participants were excluded if they displayed axial motor dysfunction or severe motor dysfunction, levodopa dyskinesia, cognitive impairment or other serious brain or medical condition or history of brain surgery. Twenty-seven of the participants were consequently enrolled into the focused ultrasound subthalamotomy group and thirteen into the sham procedure group using a random-number-generator function within Microsoft Excel. It is important to note that a crossover design was also used in the open-label crossover group at 4 months when the treatment assignment was revealed to the patients. Participants ranged from 35 to 74 years of age with a mean age of 57. At baseline, the amount of levodopa equivalent for all the participants was found to be 777.9 mg. During active treatment, real time monitoring of sonication was conducted via magnetic resonance thermomentry whereas the sham group did not receive any form of acoustic energy. A verbal survey was conducted during the procedure to mark down any adverse events. The patients were reassessed after the baseline visit at 2, 4 and 12 months where the 1-year follow-up was only completed in patients who were enrolled in the active group. Assessment of all patients was conducted using an MRI and neurologist-led neuropsychological examinations. The clinicians were also surveyed after the 4-month assessment about the success of the blinding. The study superiority of the active group with 99% power further strengthening the improvement of 53% in the active treatment group whereas the control group displayed 30% improvement of motor function. From the thirteen patients in the sham group, twelve had decided to crossover into the active group. Overall, the active treatment group reported head pain, dizziness, and head-tilting being as the most common list of adverse events. The sham procedure group reported head pain, headache, and high blood pressure as the most common. In the unblinded crossover group, three of the patients had developed new-onset dyskinesia and one had hemiballismus. In conclusion, patients suffering from severely asymmetric Parkinson’s disease revealed improvement in motor features, such as tremor and rigidity, following focused ultrasound subthalamotomy when compared to those that received a sham procedure. However, adverse events were also noted in the active treatment group.

Image: PD

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