@article {Mart{\'\i}nez-Fern{\'a}ndezjnnp-2020-325278, author = {Ra{\'u}l Mart{\'\i}nez-Fern{\'a}ndez and Sujitha Mahendran and Jose Angel Pineda-Pardo and Lukas L Imbach and Jorge U M{\'a}{\~n}ez-Mir{\'o} and Fabian B{\"u}chele and Marta del {\'A}lamo and Rafael Rodriguez-Rojas and Frida Hern{\'a}ndez-Fern{\'a}ndez and Beat Werner and Michele Matarazzo and Ignacio Obeso and Lain H Gonzalez-Quarante and G{\"u}nther Deuschl and Lennart Stieglitz and Christian R Baumann and Jose A Obeso}, title = {Bilateral staged magnetic resonance-guided focused ultrasound thalamotomy for the treatment of essential tremor: a case series study}, elocation-id = {jnnp-2020-325278}, year = {2021}, doi = {10.1136/jnnp-2020-325278}, publisher = {BMJ Publishing Group Ltd}, abstract = {Background Unilateral magnetic resonance-guided focused ultrasound (FUS) thalamotomy is efficacious for the treatment of medically refractory essential tremor (ET). Viability of bilateral FUS ablation is unexplored.Methods Patients diagnosed with medically refractory ET and previously treated with unilateral FUS thalamotomy at least 5 months before underwent bilateral treatment. The timepoints were baseline (before first thalamotomy) and FUS1 and FUS2 (4 weeks before and 6 months after second thalamotomy, respectively). The primary endpoint was safety. Efficacy was assessed through the Clinical Rating Scale for Tremor (CRST), which includes subscales for tremor examination (part A), task performance (part B) and tremor-related disability (part C).Results Nine patients were treated. No permanent adverse events were registered. Six patients presented mild gait instability and one dysarthria, all resolving within the first few weeks. Three patients reported perioral hypoesthesia, resolving in one case. Total CRST score improved by 71\% from baseline to FUS2 (from 52.3{\textpm}12 to 15.5{\textpm}9.4, p\<0.001), conveying a 67\% reduction in bilateral upper limb A+B (from 32.3{\textpm}7.8 to 10.8{\textpm}7.3, p=0.001). Part C decreased by 81\% (from 16.4{\textpm}3.6 to 3.1{\textpm}2.9, p\<0.001). Reduction in head and voice tremor was 66\% (from 1.2{\textpm}0.44 to 0.4{\textpm}0.54, p=0.01) and 45\% (from 1.8{\textpm}1.1 to 1{\textpm}0.8, p=0.02), respectively.Conclusion Bilateral staged FUS thalamotomy for ET is feasible and might be safe and effective. Voice and head tremor might also improve. A controlled study is warranted.}, issn = {0022-3050}, URL = {https://jnnp.bmj.com/content/early/2021/04/26/jnnp-2020-325278}, eprint = {https://jnnp.bmj.com/content/early/2021/04/26/jnnp-2020-325278.full.pdf}, journal = {Journal of Neurology, Neurosurgery \& Psychiatry} }