Estudio mediante estimulación magnética transcraneal del cerebelo y de la corteza parietal posterior en la distonia primaria cervical

III. OBJETIVOS DEL ESTUDIO OBJETIVOS GENERALES En los pacientes con distonía primaria cervical conocer el funcionamiento de la vía cerebelo-cortical así como la modulación que ejerce la estimulación repetitiva cerebelosa; y conocer el funcionamiento de la conexión parieto-motora y su relación con los tiempos de reacción en una tarea motora. OBJETIVOS ESPECÍFICOS Para el estudio de la conectividad entre el cerebelo y la corteza motora 1. Comparar, entre pacientes y controles, el cambio del potencial evocado motor inducido por un estímulo condicionante magnético cerebeloso y un estímulo magnético sobre la corteza motora primaria (CBI). 2. Comparar, entre pacientes y controles, los efectos de la estimulación repetitiva cerebelosa tipo iTBS 2a sobre la excitabilidad cortical (protocolo 20 Test), 2b sobre la inhibición intra-cortical a intervalo corto y facilitación intracortical (SICI/ICF) y 2c sobre la inhibición cerebelo-cortical (CBI). 3. Comparar, entre pacientes y controles, los efectos de la estimulación repetitiva cerebelosa tipo cTBS 3a sobre la excitabilidad cortical (protocolo 20 Test), 3b sobre la inhibición intra-cortical a intervalo corto y facilitación intracortical (SICI/ICF) y 3c sobre la inhibición cerebelo-cortical (CBI). Para el estudio de la conectividad entre la corteza parietal y la corteza motora 4. Comparar, entre pacientes y controles, el cambio del potencial evocado motor inducido por un estímulo condicionante magnético sobre la corteza parietal posterior y un estímulo magnético sobre la corteza motora primaria. 5. Comparar, entre pacientes y controles, los tiempos de reacción y de movimiento en una tarea motora simple 6. Estudiar la relación entre los parámetros neurofisiológicos (amplitud del potencial evocado motor) y los tiempos de reacción y de movimiento en la tarea motora estudiada

Effects of two weeks of cerebellar theta burst stimulation in cervical dystonia patients

Koch, Giacomo et al.Dystonia is generally regarded as a disorder of the basal ganglia and their efferent connections to the thalamus and brainstem, but an important role of cerebellar-thalamo-cortical (CTC) circuits in the pathophysiology of dystonia has been invoked. Here in a sham controlled trial, we tested the effects of two-weeks of cerebellar continuous theta burst stimulation (cTBS) in a sample of cervical dystonia (CD) patients. Clinical evaluations were performed by administering the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). We used TMS to measure the inhibitory connectivity between the cerebellum and the contralateral motor cortex (cerebellar brain inhibition [CBI]), and the excitability of the contralateral primary motor cortex assessing intracortical inhibition (SICI), intracortical facilitation (ICF) and cortical silent period (CSP). Paired associative stimulation (PAS) was tested to evaluate the level and the topographical specificity of cortical plasticity, which is abnormally enhanced and non-focal in CD patients. Two weeks of cerebellar stimulation resulted in a small but significant clinical improvement as measured by the TWSTRS of approximately 15%. Cerebellar stimulation modified the CBI circuits and reduced the heterotopic PAS potentiation, leading to a normal pattern of topographic specific induced plasticity. These data provide novel evidence CTC circuits could be a potential target to partially control some dystonic symptoms in patients with cervical dystonia. © 2014 Elsevier Inc. All rights reserved.Peer Reviewe

Effects of Two Weeks of Cerebellar Theta Burst Stimulation in Cervical Dystonia Patients

Dystonia is generally regarded as a disorder of the basal ganglia and their efferent connections to the thalamus and brainstem, but an important role of cerebellar-thalamo-cortical (CTC) circuits in the pathophysiology of dystonia has been invoked. Here in a sham controlled trial, we tested the effects of two-weeks of cerebellar continuous theta burst stimulation (cTBS) in a sample of cervical dystonia (CD) patients. Clinical evaluations were performed by administering the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). We used TMS to measure the inhibitory connectivity between the cerebellum and the contralateral motor cortex (cerebellar brain inhibition [CBI]), and the excitability of the contralateral primary motor cortex assessing intracortical inhibition (SICI), intracortical facilitation (ICF) and cortical silent period (CSP). Paired associative stimulation (PAS) was tested to evaluate the level and the topographical specificity of cortical plasticity, which is abnormally enhanced and non-focal in CD patients. Two weeks of cerebellar stimulation resulted in a small but significant clinical improvement as measured by the TWSTRS of approximately 15%. Cerebellar stimulation modified the CBI circuits and reduced the heterotopic PAS potentiation, leading to a normal pattern of topographic specific induced plasticity. These data provide novel evidence CTC circuits could be a potential target to partially control some dystonic symptoms in patients with cervical dystonia

Study of cerebello-thalamocortical pathway by transcranial magnetic stimulation in Parkinson's disease

none8Although functional changes in the activation of the cerebellum in Parkinson's disease (PD) patients have been consistently described, it is still debated whether such altered cerebellar activation is a natural consequence of PD pathophysiology or rather it involves compensatory mechanisms.noneCarrillo, Fátima; Palomar, Francisco J; Conde, Virginia; Diaz-Corrales, Francisco J; Porcacchia, Paolo; Fernández-Del-Olmo, Miguel; Koch, Giacomo; Mir, PabloCarrillo, Fátima; Palomar, Francisco J; Conde, Virginia; Diaz-Corrales, Francisco J; Porcacchia, Paolo; Fernández-Del-Olmo, Miguel; Koch, Giacomo; Mir, Pabl

Parieto-motor cortical dysfunction in primary cervical dystonia

Dystonia is considered as a motor network disorder involving the dysfunction of the posterior parietal cortex, a region involved in preparing and executing reaching movements

Study of cerebello-thalamocortical pathway by transcranial magnetic stimulation in Parkinson's disease

Although functional changes in the activation of the cerebellum in Parkinson's disease (PD) patients have been consistently described, it is still debated whether such altered cerebellar activation is a natural consequence of PD pathophysiology or rather it involves compensatory mechanisms

Abnormal cerebellar connectivity and plasticity in isolated cervical dystonia

There is increasing evidence that supports the role of the cerebellum in the pathophysiology of dystonia. We used transcranial magnetic stimulation to test the hypothesis that patients with cervical dystonia may have a disrupted cerebellar cortical connectivity at rest, and that cerebellar plasticity is altered too. We enrolled 12 patients with isolated cervical dystonia and 13 controls. A paired-pulse transcranial magnetic stimulation protocol was applied over the right cerebellum and the left primary motor area. Changes in the amplitude of motor evoked potentials were analysed. Continuous and intermittent Theta Burst Stimulation over the cerebellum was also applied. The effects of these repetitive protocols on cortical excitability, on intra-cortical circuits and on cerebellar cortical inhibition were analysed. In healthy subjects, but not in dystonic patients, a conditioning stimulus over the cerebellum was able to inhibit the amplitude of the motor evoked potentials from primary motor cortex. In healthy subjects continuous and intermittent cerebellar Theta Burst Stimulation were able to decrease and increase respectively motor cortex excitability. Continuous Theta Burst Stimulation was able to abolish the cerebellar cortical inhibition observed in basal condition. These effects were not observed in patients with cervical dystonia. Cerebellar cortical connectivity and cerebellar plasticity is altered at rest in patients with cervical dystonia.This research was supported by grants from the Ministerio de Economía y Competitividad de España (SAF2007-60700), the Instituto de Salud Carlos III (CP08/00174, PI10/01674, PI13/01461), the Consejería de Economía, Innovación, Ciencia y Empresa de la Junta de Andalucía (CVI-02526, CTS-7685), the Consejería de Salud y Bienestar Social de la Junta de Andalucía (PI-0377/2007, PI-0741/2010, PI-0437-2012, PI-0471/2013), the Sociedad Andaluza de Neurología, the Fundación Alicia Koplowitz, the Fundación Mutua Madrileña and the Jaques and Gloria Gossweiler Foundation.Peer reviewe

Effects of two weeks of cerebellar theta burst stimulation in cervical dystonia patients

Dystonia is generally regarded as a disorder of the basal ganglia and their efferent connections to the thalamus and brainstem, but an important role of cerebellar-thalamo-cortical (CTC) circuits in the pathophysiology of dystonia has been invoked. Here in a sham controlled trial, we tested the effects of two-weeks of cerebellar continuous theta burst stimulation (cTBS) in a sample of cervical dystonia (CD) patients. Clinical evaluations were performed by administering the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). We used TMS to measure the inhibitory connectivity between the cerebellum and the contralateral motor cortex (cerebellar brain inhibition [CBI]), and the excitability of the contralateral primary motor cortex assessing intracortical inhibition (SICI), intracortical facilitation (ICF) and cortical silent period (CSP). Paired associative stimulation (PAS) was tested to evaluate the level and the topographical specificity of cortical plasticity, which is abnormally enhanced and non-focal in CD patients. Two weeks of cerebellar stimulation resulted in a small but significant clinical improvement as measured by the TWSTRS of approximately 15%. Cerebellar stimulation modified the CBI circuits and reduced the heterotopic PAS potentiation, leading to a normal pattern of topographic specific induced plasticity. These data provide novel evidence CTC circuits could be a potential target to partially control some dystonic symptoms in patients with cervical dystonia