Article

OBJECTIVES: To examine for individual factors that may predict response to
inhibitory repetitive transcranial magnetic stimulation (rTMS) in focal hand
dystonia (FHD); to present the method for determining optimal stimulation to
increase inhibition in a given patient; and to examine individual responses to
prolonged intervention.
DESIGN: Single-subject design to determine optimal
parameters to increase inhibition for a given subject and to use the selected
parameters once per week for 6 weeks, with 1-week follow-up, to determine
response. SETTING: Clinical research laboratory. PARTICIPANTS: A volunteer sample
of subjects with FHD (N = 2). One participant had transcranial magnetic
stimulation responses indicating impaired inhibition, and the other had responses
within normative limits. INTERVENTIONS: There were 1200 pulses of 1-Hz rTMS
delivered using 4 different stimulation sites/intensity combinations: primary
motor cortex at 90% or 110% of resting motor threshold (RMT) and dorsal premotor
cortex (PMd) at 90% or 110% of RMT. The parameters producing the greatest
within-session increase in cortical silent period (CSP) duration were then used
as the intervention. MAIN OUTCOME MEASURES: Response variables included
handwriting pressure and velocity, subjective symptom rating, CSP, and short
latency intracortical inhibition and facilitation.
RESULTS: The individual with
baseline transcranial magnetic stimulation responses indicating impaired
inhibition responded favorably to the repeated intervention, with reduced
handwriting force, an increase in the CSP, and subjective report of moderate
symptom improvement at 1-week follow-up. The individual with normative baseline
responses failed to respond to the intervention. In both subjects, 90% of RMT to
the PMd produced the greatest lengthening of the CSP and was used as the
intervention. CONCLUSIONS:
An individualized understanding of neurophysiological
measures can be an indicator of responsiveness to inhibitory rTMS in focal
dystonia, with further work needed to determine likely responders versus
nonresponders.
CI - Copyright (c) 2015 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS