Produção Nacional
Revisado por pares
Dentate nucleus stimulation for essential tremor
2020; Elsevier BV; Volume: 82; Linguagem: Inglês
10.1016/j.parkreldis.2020.12.001
ISSN1873-5126
AutoresIsabela Bruzzi Bezerra Paraguay, Carina França, Kleber Paiva Duarte, Juliete Melo Diniz, Ricardo Galhardoni, Valquíria Aparecida da Silva, Ricardo Iglésio, André Bortolon Bissoli, Janaína Reis Menezes, Rafael Bernhart Carra, Guilherme Lepski, Egberto Reis Barbosa, Daniel Ciampi de Andrade, Manoel Jacobsen Teixeira, Rubens Gisbert Cury,
Tópico(s)Neuroscience and Neural Engineering
Resumo•Thalamic deep brain stimulation (DBS) is a well-recognized therapy for refractory essential tremor.•However, cortical atrophy and microangiopathy may present a greater surgical risk in older patients.•In this pilot case, dentate nucleus DBS improved tremor in a patient with refractory Essential Tremor. Thalamus ventral intermediate nucleus deep brain stimulation is a well-recognized therapy for refractory essential tremor (ET) [[1]Cury R.G. Fraix V. Castrioto A. Pérez Fernández M.A. Krack P. Chabardes S. Seigneuret E. Alho E.J.L. Benabid A.-L. Moro E. Thalamic deep brain stimulation for tremor in Parkinson disease, essential tremor, and dystonia.Neurology. 2017; 89: 1416-1423https://doi.org/10.1212/WNL.0000000000004295Crossref PubMed Scopus (121) Google Scholar]. However, cortical atrophy and microangiopathy may present a greater surgical risk especially in older patients. In this context, alternative targets for neuromodulation in ET may be relevant. Cerebellar neuromodulation has emerged with promising results in movement disorders [[2]França C. de Andrade D.C. Teixeira M.J. Galhardoni R. Silva V. Barbosa E.R. Cury R.G. Effects of cerebellar neuromodulation in movement disorders: a systematic review.Brain Stimul. 2018; 11: 249-260https://doi.org/10.1016/j.brs.2017.11.015Abstract Full Text Full Text PDF PubMed Scopus (53) Google Scholar]. Although there have been only a few studies, non-invasive and invasive stimulation over the cerebellum has been shown to potentially improve ataxia, dystonia, and tremor [2França C. de Andrade D.C. Teixeira M.J. Galhardoni R. Silva V. Barbosa E.R. Cury R.G. Effects of cerebellar neuromodulation in movement disorders: a systematic review.Brain Stimul. 2018; 11: 249-260https://doi.org/10.1016/j.brs.2017.11.015Abstract Full Text Full Text PDF PubMed Scopus (53) Google Scholar, 3Cury R.G. França C. Silva V. Barbosa E.R. Capato T.T.C. Lepski G. Duarte K.P. Teixeira M.J. Ciampi de Andrade D. Effects of dentate nucleus stimulation in spinocerebellar ataxia type 3.Park. Relat. Disord. 2019; 69: 91-93https://doi.org/10.1016/j.parkreldis.2019.10.029Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar, 4Teixeira M.J. Cury R.G. Galhardoni R. Barboza V.R. Brunoni A.R. Alho E. Lepski G. Ciampi de Andrade D. Deep brain stimulation of the dentate nucleus improves cerebellar ataxia after cerebellar stroke.Neurology. 2015; 85: 2075-2076https://doi.org/10.1212/WNL.0000000000002204Crossref PubMed Scopus (30) Google Scholar, 5Brown E.G. Bledsoe I.O. Luthra N.S. Miocinovic S. Starr P.A. Ostrem J.L. Cerebellar deep brain stimulation for acquired hemidystonia.Mov. Disord. Clin. Pract. 2020; 7: 188-193https://doi.org/10.1002/mdc3.12876Crossref PubMed Scopus (14) Google Scholar]. Here, we report the case of a patient with refractory ET who underwent dentate nucleus DBS (DN DBS). A 76-year-old right-handed male presented with a 50-year history of tremor in uppers limbs and voice that became incapacitating over the last 20 years. He was diagnosed with essential tremor and had been taking 200 mg of primidone with initial improvement, but symptoms worsened over the last 5 years. Propranolol was not tolerated over 40 mg due to hypotension effect. By the time of his first visit he was not able to write, drink, or eat because of the high amplitude tremor (Motor part of Fahn, Tolosa, Marin Tremor Scale = 65/120). Considering the refractoriness of his symptoms and severity of the tremor he was referred to DBS surgery. However, because of his marked brain atrophy and leukoencephalopathy, considering the higher risks of bleeding, the dentate nucleus was proposed as a target. The study was approved by the local ethics committee and the patient provided written informed consent. The surgical procedure was described elsewhere [[3]Cury R.G. França C. Silva V. Barbosa E.R. Capato T.T.C. Lepski G. Duarte K.P. Teixeira M.J. Ciampi de Andrade D. Effects of dentate nucleus stimulation in spinocerebellar ataxia type 3.Park. Relat. Disord. 2019; 69: 91-93https://doi.org/10.1016/j.parkreldis.2019.10.029Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar] and is detailed in supplementary file 1. Fig. 1 illustrates the target. The DBS was turned on one month after surgery. During the follow-up, we tested a range of frequencies between 6 and 150 Hz and pulse widths between 60 and 210 μs. We tested each electrode separately and then both sides together, first using monopolar and after using bipolar settings. The tremor improvement was seen ipsilateral to the stimulated lead when tested unilaterally. The patient was assessed every 28 days and parameters were changed in all visits according to tendencies, patient's improvement, or collateral effects. Once the best parameters were defined, nine months after surgery, the configuration was kept constant until the double-blind evaluation, at the one-year follow-up. During the double-blind evaluation, the patient was assessed under off- and on-stimulation conditions. Both conditions were introduced 30 min before the clinical ratings in randomized order, with both patient and evaluator blinded to the DBS status. The best settings were bipolar and activated the most proximal contacts (left DN = 1.6 mA, 78 μs, 138 Hz; right DN = 1.2 mA, 117 μs, 138 Hz). We observed an improvement in tremor with a 48% reduction in Motor part of Fahn, Tolosa, Marin Tremor Scale (from 66/120 to 34/120) and a 71% reduction in tremor amplitude using the Weber-Fechner Relationship when comparing the active versus sham phases. Part of this evaluation can be seen at the supplementary video. Dizziness was noted with a higher pulse width on monopolar stimulation and some habituation could be seen over the months. Patients’ global impression of change (PGIC scale) during the last follow-up was 6 (better, and definitive improvement that has made a real difference). In this pilot case, DN DBS in a patient with ET was a safe and well-tolerated procedure with no major side effects during the 12-month follow-up period. The effect on tremor was remarkable in the blinded assessment one year after the surgery. Additionally, the stimulation significantly improved his functionally, including the handwriting (from 4 to 2 points in item 10 of Fahn, Tolosa, Marin Tremor Scale). Thus far, clinical studies have only evaluated the effects of DN DBS in single cases. Although only small improvements were noted, DN DBS was effective for treating ataxia in SCA type 3 [[3]Cury R.G. França C. Silva V. Barbosa E.R. Capato T.T.C. Lepski G. Duarte K.P. Teixeira M.J. Ciampi de Andrade D. Effects of dentate nucleus stimulation in spinocerebellar ataxia type 3.Park. Relat. Disord. 2019; 69: 91-93https://doi.org/10.1016/j.parkreldis.2019.10.029Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar], cerebellar stroke [[4]Teixeira M.J. Cury R.G. Galhardoni R. Barboza V.R. Brunoni A.R. Alho E. Lepski G. Ciampi de Andrade D. Deep brain stimulation of the dentate nucleus improves cerebellar ataxia after cerebellar stroke.Neurology. 2015; 85: 2075-2076https://doi.org/10.1212/WNL.0000000000002204Crossref PubMed Scopus (30) Google Scholar], and dystonia [[5]Brown E.G. Bledsoe I.O. Luthra N.S. Miocinovic S. Starr P.A. Ostrem J.L. Cerebellar deep brain stimulation for acquired hemidystonia.Mov. Disord. Clin. Pract. 2020; 7: 188-193https://doi.org/10.1002/mdc3.12876Crossref PubMed Scopus (14) Google Scholar]. To our knowledge, this is the first report for ET. Treatment involving DBS of the VIM and posterior subthalamic area targeting the fibers of the dentatothalamic tract (DTT) has been shown to be effective for treating ET. We postulate that DN stimulation can be effective in reducing tremor by modulating the nucleus excitatory activity and targeting the DTT at its origin. Larger studies are necessary to address whether DN DBS is in fact effective over short- and long-term periods for ET and to better determine the optimal site of electrode placement and parameters for stimulation. Financial disclosure related to research covered in this article: The authors report that this project was partially sponsored by Abbott, Chicago, IL, USA . The authors report no other relevant disclosures regarding this study. This project was partially sponsored by Abbott, Chicago, IL, USA .
Referência(s)