Effect of Thalamic versus Pallidal Deep Brain Stimulation on Head Tremor in Dystonic and Essential Tremor Patients-A Retrospective Video-Blinded Study.

BACKGROUND: Head tremor is common in dystonia syndromes and difficult to treat. Deep brain stimulation (DBS) is a therapeutic option in medically-refractory cases. In most DBS-centers, the globus pallidus internus (GPi) is targeted in patients with predominant dystonia and the ventrointermediate nucleus of the thalamus (Vim) in predominant tremor. The aim of the study was to evaluate the effect of GPi- versus Vim-DBS in dystonic or essential head tremor. METHODS: All patients with dystonia or essential tremor (ET) (n = 381) who underwent DBS surgery at our institution between 1999 and 2020 were screened for head tremor in our database according to predefined selection criteria. Of the 33 patients meeting inclusion criteria tremor and dystonia severity were assessed at baseline, short- (mean 10 months) and long-term follow-up (41 months) by two blinded video-raters. RESULTS: Twenty-two patients with dystonic head tremor received either GPi- (n = 12) or Vim-stimulation (n = 10), according to the prevailing clinical phenotype. These two groups were compared with 11 patients with ET, treated with Vim-stimulation. The reduction in head tremor from baseline to short- and long-term follow-up was 60-70% and did not differ significantly between the three groups. CONCLUSIONS: GPi-DBS effectively and sustainably reduced head tremor in idiopathic dystonia. The effect was comparable to the effect of Vim-DBS on head tremor in dystonia patients with predominant limb tremor and to the effect of Vim-DBS on head tremor in ET.

Retrocollis, anterocollis or head tremor may predict the spreading of dystonic movements in primary cervical dystonia / Retrocolis, anterocolis ou tremor cefálico podem predizer a progressão dos movimentos distônicos em pacientes com distonia cervical primária

BACKGROUND AND PURPOSE: Few studies have attempted to develop clinical predictors for cervical dystonia (CD) aiming at progression of the dystonic movement. METHOD: We retrospectively evaluated 73 patients with primary CD who underwent treatment with Botulinum toxin type-A (BTX-A). The patients were assembled in two groups according to the spread of dystonia during follow-up: spreading and non-spreading CD. We performed a binary logistic regression model using spreading of cervical dystonia as dependent variable aiming to find covariates which increase the risk of spreading. RESULTS: Our logistic regression model found the following covariates and their respective risk ratios: time of disease >18.5 months=2.4, retrocollis=1.9, anterocollis=1.8, head tremor=1.6. CONCLUSION: Time of disease >18.5 months, retrocollis, anterocollis and head tremor may predict spreading of dystonic movement to other regions of the body in CD patients.

INTRODUÇÃO: Poucos estudos avaliam preditores clínicos de progressão dos movimentos distônicos, para além da região cervical, em pacientes com distonia cervical (DC) primária. MÉTODO: Avaliamos, retrospectivamente, 73 pacientes com DC primária, que tinham sido submetidos ao tratamento com a toxina botulínica tipo A (BTX-A). Estes pacientes foram divididos em dois grupos de acordo com a progressão ou não da DC para outras áreas do corpo. Aplicamos um modelo de regressão logística binária usando a progressão da distonia como variável dependente com o objetivo de identificar co-variáveis que aumentassem o risco de progressão. RESULTADOS: O modelo de regressão logístico identificou as seguintes co-variáveis como preditoras de progressão e seus respectivos índices de risco: tempo de doença >18,5 meses=2,4, retrocolis=1,9, anterocolis=1,8, tremor cefálico=1,6. CONCLUSÃO: Tempo de doença >18,5 meses, retrocolis, anterocolis, e tremor cefálico podem predizer a progressão do movimento distônico para outras regiões do corpo em pacientes com DC primária.

Head tremor in patients with cervical dystonia: different outcome? / Tremor cefálico em pacientes com distonia cervical: evolução diferente?

OBJECTIVE: The association of cervical dystonia (CD) with other movement disorders have been already described, but data on clinical outcome regarding these patients are scant. The aim of this paper was to investigate whether patients with CD and head tremor (HT) would have a different outcome regarding to botulinum toxin type-A (BTX-A) treatment response and clinical and demographic parameters. METHOD: We retrospectively evaluated 118 medical charts of patients with CD and divided them into two groups: with (HT+) and without (HT-) head tremor. We compared the following clinical and demographic parameters: age at onset, disease duration, progression of symptoms, etiology, familial history, presence of hand tremor. We also analyzed the response to BTX-A according to Tsui score in both groups. RESULTS: The occurrence of head tremor in our sample was of 38.2 percent. The occurrence of postural hand tremor in the patients from the HT+ group was higher than in the HT- one (p=0.015) and if we compare BTX-A response in each group, we observe that patients with HT present a better outcome in a setting of longer follow-up. In HT+ group, Tsui score pre treatment was 10 (6-12.5) and after follow-up was 8 (5.5-10.5); p<0.001. In HT- group there was no significant difference 9 (7-12) in pre treatment and after follow-up; p=0.07. CONCLUSION: According to our data it seems that head tremor may influence the clinical outcome or treatment response with BTX-A in patients with CD.

OBJETIVO: A associação de distonia cervical (DC) com outros transtornos do movimento já foi descrita, mas há poucos dados quanto à evolução clínica destes pacientes. Avaliamos se os pacientes com DC e tremor cefálico (TC) apresentam características clínicas e demográficas, assim como a resposta ao tratamento com toxina botulínica tipo A, diferentes. MÉTODOS: Analisamos retrospectivamente 118 prontuários de pacientes com DC e os dividimos em dois grupos: com (TC+) e sem (TC-) tremor cefálico. Comparamos os seguintes parâmetros clínicos e demográficos entre os grupos: idade de início, duração da doença, progressão de sintomas, etiologia, história familiar, presença de tremor em mãos. Também analisamos a resposta ao tratamento com toxina botulínica de acordo com escore Tsui em ambos os grupos. RESULTADOS: A ocorrência de tremor cefálico em nosso grupo de pacientes foi 38,2 por cento. A ocorrência de tremor postural nas mãos em pacientes TC+ foi maior (p=0,015) e se compararmos a resposta ao tratamento com toxina botulínica em cada grupo, observamos que os pacientes com TC têm melhor evolução em uma situação de seguimento mais prolongado. No grupo TC+, o escore Tsui pré-tratamento foi 10 (6-12,5) e após o período de "follow-up" foi 8 (5,5-10,5); p<0,001. No grupo TC-, não houve diferença significante: 9 (7-12) no pré-tratamento e após período de "follow-up"; p=0,07. CONCLUSÃO: Nossos dados apontam que o tremor cefálico pode influenciar a evolução clínica ou resposta ao tratamento com toxina botulínica em pacientes com DC.