Effects on cognition and quality of life with unilateral magnetic resonance–guided focused ultrasound thalamotomy for essential tremor

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>Although neurosurgical procedures are effective treatments for controlling involuntary tremor in patients with essential tremor (ET), they can cause cognitive decline, which can affect quality of life (QOL). The purpose of this study is to assess the changes in the neuropsychological profile and QOL of patients following MR-guided focused ultrasound (MRgFUS) thalamotomy for ET.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>The authors prospectively analyzed 20 patients with ET who underwent unilateral MRgFUS thalamotomy at their institute in the period from March 2012 to September 2014. Patients were regularly evaluated with the Clinical Rating Scale for Tremor (CRST), neuroimaging, and cognition and QOL measures. The Seoul Neuropsychological Screening Battery was used to assess cognitive function, and the Quality of Life in Essential Tremor Questionnaire (QUEST) was used to evaluate the postoperative change in QOL.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>The total CRST score improved by 67.3% (from 44.75 ± 9.57 to 14.65 ± 9.19, p &lt; 0.001) at 1 year following MRgFUS thalamotomy. Mean tremor scores improved by 68% in the hand contralateral to the thalamotomy, but there was no significant improvement in the ipsilateral hand. Although minimal cognitive decline was observed without statistical significance, memory function was much improved (p = 0.031). The total QUEST score also showed the same trend of improving (64.16 ± 17.75 vs 27.38 ± 13.96, p &lt; 0.001).</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>The authors report that MRgFUS thalamotomy had beneficial effects in terms of not only tremor control but also safety for cognitive function and QOL. Acceptable postoperative changes in cognition and much-improved QOL positively support the clinical significance of MRgFUS thalamotomy as a new, favorable surgical treatment in patients with ET.</jats:p></jats:sec>

Cognitive safety after unilateral magnetic resonance-guided focused ultrasound thalamotomy for essential tremor

“…A previous study including 20 patients who were all followed for 6 months after MRgFUS thalamotomy showed no worsening and found an improvement in memory domain 5. Our study definitively shows the cognitive safety of this procedure after a longer period of follow-up.…”

Treatment of essential tremor: current status

“…Another form of lesional surgery is the MRgFUS that uses high-intensity focused ultrasound (table 4). 101–109 MRgFUS-thalamotomy has been reported to produce significant improvement in hand tremor, clinical rating scales and quality of life and the benefits have been maintained at 2 years’ follow-up 102 110. The side effects from unilateral MRgFUS-thalamotomy are paraesthesias and imbalance whereas bilateral targeting causes cognitive, gait, balance and speech disturbances 102 111–113.…”

“…The side effects from unilateral MRgFUS-thalamotomy are paraesthesias and imbalance whereas bilateral targeting causes cognitive, gait, balance and speech disturbances 102 111–113. In summary, the side effects from lesioning surgeries are more pronounced and permanent after bilateral compared with unilateral procedures, thus they are currently performed only unilaterally 97 101 102 109 111 113…”

Editorial. Tremor, thalamotomy, and cognition

“…In their paper, Jung et al report on the first study to specifically address neurocognitive changes after MRgFUS thalamotomy for medically refractory ET. 6 In high-intensity MRgFUS, ultrasound penetrates the skull from multiple sources to converge on a discrete intracranial target, raising tissue temperature and generating a thermocoagulative lesion. The advantages of MRgFUS are real-time image guidance and the ability to raise temperatures to sublesional levels to assess for adverse events prior to generating a permanent lesion.…”

“…Jung et al report tremor, neurocognitive, and QOL assessment in 20 patients with ET who underwent left-sided MRgFUS thalamotomy. 6 The Seoul Neuropsychological Screening Battery (SNSB), commonly used in Korea for dementia and other neurological disorders, was applied to test domains of attention, language, visuospatial function, verbal memory, and frontal executive function. 1 A blinded assessor administered the test at baseline and 6 months after treatment.…”