A Systematic Review Comparing Focused Ultrasound Surgery With Radiosurgery for Essential Tremor

Abstract

BACKGROUND: Focused ultrasound (FUS-T) and stereotactic radiosurgery thalamotomy (SRS-T) targeting the ventral intermediate nucleus are effective incisionless surgeries for essential tremor (ET). However, their efficacy for tremor reduction and, importantly, adverse event incidence have not been directly compared. OBJECTIVE: To present a comprehensive systematic review with network meta-analysis examining both efficacy and adverse events (AEs) of FUS-T vs SRS-T for treating medically refractory ET. METHODS: We conducted a systematic review and network meta-analysis according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, using the PubMed and Embase databases. We included all primary FUS-T/SRS-T studies with approximately 1-year follow-up, with unilateral Fahn-Tolosa-Marin Tremor Rating Scale or Clinical Rating Scale for Tremor scores prethalamotomy/post-thalamotomy and/or AEs. The primary efficacy outcome was Fahn-Tolosa-Marin Tremor Rating Scale A+B score reduction. AEs were reported as an estimated incidence. RESULTS: Fifteen studies of 464 patients and 3 studies of 62 patients met inclusion criteria for FUS-T/SRS-T efficacy comparison, respectively. Network meta-analysis demonstrated similar tremor reduction between modalities (absolute tremor reduction: FUS-T: −11.6 (95% CI: −13.3, −9.9); SRS-T: −10.3 (95% CI: −14.2, −6.0). FUS-T had a greater 1-year adverse event rate, particularly imbalance and gait disturbances (10.5%) and sensory disturbances (8.3%). Contralateral hemiparesis (2.7%) often accompanied by speech impairment (2.4%) were most common after SRS-T. There was no correlation between efficacy and lesion volume. CONCLUSION: Our systematic review found similar efficacy between FUS-T and SRS-T for ET, with trend toward higher efficacy yet greater adverse event incidence with FUS-T. Smaller lesion volumes could mitigate FUS-T off-target effects for greater safety.

Unilateral Magnetic Resonance Imaging–Guided Laser Interstitial Thermal Therapy Thalamotomy for Essential Tremor

“…We successfully targeted and ablated the VIM nucleus of the thalamus, resulting in expected clinical outcomes that are comparable to those seen with RF, GKRS, and MRIg-FUS thalamotomies. 9,10,23 In our study, we observed an 83.37% reduction in tremor at Data are number of patients. Transient AEs were those that appeared during or after the thalamotomy procedure and vanished within a month.…”

“…7,8 Alternative lesional brain surgery procedures, such as thalamotomy using radiofrequency (RF), gamma-knife radiosurgery (GKRS), or magnetic resonance imaging-guided focused ultrasound (MRIg-FUS), have been shown to be efficacious to manage tremor symptoms in individuals for whom DBS is unsuitable. 5,9,10 Recently, a novel technology has emerged in the field of lesional brain surgery, known as MRI-guided laser interstitial thermal therapy (MRIg-LITT). 11 MRIg-LITT has been shown to be effective and safe in management of brain tumors and seizure disorders.…”

Impact of biologically effective dose on tremor decrease after stereotactic radiosurgical thalamotomy for essential tremor: a retrospective longitudinal analysis

“…During the past decade and aiming at the same surgical target, HIFU has been suggested as an appealing procedure, producing a controlled thermocoagulation, with an immediate clinical effect [ 12 ]. A recent systematic review compared the results of HIFU and SRS for ET [ 21 ]. The authors found similar efficacy between the two techniques, with a trend towards higher efficacy yet greater adverse events incidence with HIFU [ 21 ].…”

“…A recent systematic review compared the results of HIFU and SRS for ET [ 21 ]. The authors found similar efficacy between the two techniques, with a trend towards higher efficacy yet greater adverse events incidence with HIFU [ 21 ]. It was concluded that smaller lesion volumes could mitigate FUS-T off-target effects for greater safety [ 21 ].…”

“…The authors found similar efficacy between the two techniques, with a trend towards higher efficacy yet greater adverse events incidence with HIFU [ 21 ]. It was concluded that smaller lesion volumes could mitigate FUS-T off-target effects for greater safety [ 21 ]. This is in agreement with a recent statement by Iorio-Morin et al [ 19 ] suggesting that HIFU is being rapidly adopted for the treatment of ET, while the superior popularity of HIFU over SRS appears to rise for reasons other than differences in clinical outcomes.…”