Clinical Trial: Abnormal Movements, Cerebellum and Sensorimotor : Oculomotor Study

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Adaptation Sensorimotrice, Cervelet et Mouvements Anormaux: Projet d'étude Oculomotrice

Brief Summary:

Dystonia is a movement disorder characterized by involuntary, sustained, often repetitive muscle contractions of opposite muscles that lead to abnormal twisting movements or odd postures. Essential tremor is a slowly progressive neurologic disorder characterized by the appearance of a tremor during the voluntary movement. The pathophysiology of dystonia or essential tremor is not fully elucidated. Dystonia and essential tremor are associated with dysfunction of the sensorimotor basal ganglia-cortical network and involvement of the cerebellum and cerebellar pathways has also been recently suggested.

The investigators propose to study 30 patients having a primary dystonia (15 DYT11 genetically documented), 15 patients having an essential tremor without deep brain stimulation and 15 patients having an essential tremor with deep brain stimulation.A group of 30 healthy volunteers will be recruited and tested according to the same modalities. They will be paired in sex and age. 30 patients having a Parkinson disease will be also tested.

Eye position will be sampled with a video-based monocular eye tracker (SMI, Germany) before and immediately after an adaptation task. Saccade adaptation is evaluated as the percentage change in the mean saccade amplitude between pre-test and post-test.

Expected results:

  • no or fewer alteration of the performance to the adaptation task in the Parkinson group than in the Essential Tremor group/ dystonia group.
  • abnormal reactive saccade backward adaptation in the Dystonia group and Essential Tremor group, providing further neurophysiological evidence of cerebellar dysfunction.

Detailed Summary:

Dystonia is a movement disorder characterized by involuntary, sustained, often repetitive muscle contractions of opposite muscles that lead to abnormal twisting movements or odd postures. Essential tremor is a slowly progressive neurologic disorder characterized by the appearance of a tremor during the voluntary movement. High frequency stimulation of the ventral intermedius nucleus (Vim) of the thalamus, relay for the cerebellar output, is successfully used for the treatment of severe essential tremor. It occasionally induces adverse event such as balance disorders or cerebellar symptoms. The pathophysiology of dystonia or essential tremor is not fully elucidated. Dystonia and essential tremor are associated with dysfunction of the sensorimotor basal ganglia-cortical network and involvement of the cerebellum and cerebellar pathways has also been recently suggested. It seems that dystonia and essential tremor could be the result of basal ganglia or cerebellar dysfunction, or from dysfunction of structures controlled at the same time by the cerebellum and the basal ganglia.

methodology: We propose to study 30 patients having a primary dystonia (15 DYT11 genetically documented), 15 patients having an essential tremor without deep brain stimulation and 15 patients having an essential tremor with deep brain stimulation.

A group of 30 healthy volunteers will be recruited and tested according to the same modalities. They will be paired in sex and age. 30 patients having a Parkinson disease will be also tested.

The subjects will be seated in darkness facing a screen located 60 cm before their eyes, their chin on a chin strap and their forehead placed against a frontal support. Eye position is sampled at 500 Hz with a video-based monocular eye tracker (SMI, Germany). Each recording
Sponsor: Institut National de la Santé Et de la Recherche Médicale, France

Current Primary Outcome:

  • Saccadic adaptation [ Time Frame: between the pre-test and post-test, maximum 4 hours ]
    Saccadic adaptation, evaluated as the percentage of changes in the mean saccade amplitude between the pre-test and post-test.
  • Characteristics of the saccade [ Time Frame: measured during the analysis of the recorded session, maximum 4 hours ]
    latency, velocity, duration of the saccade


Original Primary Outcome: Same as current

Current Secondary Outcome:

Original Secondary Outcome:

Information By: Institut National de la Santé Et de la Recherche Médicale, France

Dates:
Date Received: May 18, 2011
Date Started: March 2011
Date Completion:
Last Updated: February 23, 2016
Last Verified: February 2016