Clinical Trial: Sensorimotor Mapping in Patients With Writer's Cramp

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Corticomotor Plasticity as a Biomarker for Functional Improvement After Botulinium Treatment in Writer's Cramp

Brief Summary: Writer's cramp (WC) is a form of focal dystonia, a movement disorder characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive movements, postures, or both. It typically manifests while writing, making handwriting impossible in the most severe cases. Treatment can be difficult, but one effective and well-tolerated treatment consists in local muscle injections with botulinum toxin. Although clinical improvement seems to be related to focal muscle chemodenervation, central plasticity changes may occur. The main aim of the study is to characterize and quantify the changes in intrinsic hand muscle cortical representations at rest and during isometric contractions of the finger muscles before and after treatment with botulinum toxin and the changes in sensorimotor integration in patients with writer's cramp.

Detailed Summary:

Fifteen WC patients will be enrolled in the study. A newly developed neuronavigated and robotized Transcranial Magnetic Stimulation (TMS) mapping approach will be used. It will generate a linear mediolateral excitability profile for two intrinsic hand muscle based on the mean Motor Evoked Potentials (MEPs) amplitude at each stimulation site. Changes in excitability profiles will reflect spatial reorganization of cortical motor output maps of the hand muscles. To measure afferent inhibition, the same mapping procedure will be repeated with a brief peripheral electrical stimulation prior the TMS pulse. These Short Afferent Inhibition (SAI) profiles will reflect the influence of the primary sensory cortex over the motor cortex. Finally, the stimulation grid will be translated to the primary somatosensory cortex and a paired pulse TMS paradigm will be applied just after a digital nerve stimulation. It will generate afferent signal processing profiles based on subjective perception for the index finger and the little finger. Participants will be tested before the botulinum toxin injections and at three different time points after the injections (7 days, 1 month and 3 months after). Botulinum toxin injections will be performed using ultrasound guide together with electromyography/nerve stimulation into the clinical affected hand muscles. Muscle selection for injections will be based on clinical criteria of postural deviation of the hand and fingers and responsible muscle forces. The dose will be chosen according to published clinical recommendation concerning starting dose for WC after the clinical examination, usually between 5 and 10 units of Xeomin® both for flexor and extensor hand/forearm muscles.

To precisely assess treatment efficacy, the Writer's Cramp Rating Scale (WCRS) as well as computer-based hand writing analyses and standard sensorimotor tests of hand functi
Sponsor: University Hospital, Grenoble

Current Primary Outcome: Corticospinal excitability profiles of intrinsic hand muscles [ Time Frame: This measure will be performed before the injection of botulinum toxin and 7 days after, 30 days after and 3 months after the injection. ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

Original Secondary Outcome:

Information By: University Hospital, Grenoble

Dates:
Date Received: February 24, 2017
Date Started: February 20, 2017
Date Completion: May 19, 2018
Last Updated: March 14, 2017
Last Verified: March 2017