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Mixed effectiveness of rTMS and retraining in the treatment of focal hand dystonia.

Kimberley TJ, Schmidt RL, Chen M, Dykstra DD, Buetefisch CM - Front Hum Neurosci (2015)

Bottom Line: Contrary to our hypothesis, group analyses revealed no additional benefit from the SMR training vs.The patient rated improvements were accompanied by a moderate effect size suggesting clinical meaningfulness.These results provide encouragement for further investigation of rTMS in FHD with a need to optimize a secondary intervention and determine likely responders vs. non-responders.

View Article: PubMed Central - PubMed

Affiliation: Program in Physical Therapy, Brain Plasticity Laboratory, Department of Physical Medicine and Rehabilitation, University of Minnesota Minneapolis, MN, USA.

ABSTRACT

Unlabelled: Though the pathophysiology of dystonia remains uncertain, two primary factors implicated in the development of dystonic symptoms are excessive cortical excitability and impaired sensorimotor processing. The aim of this study was to determine the functional efficacy of an intervention combining repetitive transcranial magnetic stimulation (rTMS) and sensorimotor retraining. A randomized, single-subject, multiple baseline design with crossover was used to examine participants with focal hand dystonia (FHD) (n = 9).

Intervention: 5 days rTMS + sensorimotor retraining (SMR) vs. Five days rTMS + control therapy (CTL) (which included stretching and massage). The rTMS was applied to the premotor cortex at 1 Hz at 80% resting motor threshold for 1200 pulses. For sensorimotor retraining, a subset of the Learning-based Sensorimotor Training program was followed. Each session in both groups consisted of rTMS followed immediately by 30 min of the therapy intervention (SMR or CTL). Contrary to our hypothesis, group analyses revealed no additional benefit from the SMR training vs. CTL. When analyzed across group however, there was significant improvement from the first baseline assessment in several measures, including tests of sensory ability and self-rated changes. The patient rated improvements were accompanied by a moderate effect size suggesting clinical meaningfulness. These results provide encouragement for further investigation of rTMS in FHD with a need to optimize a secondary intervention and determine likely responders vs. non-responders.

No MeSH data available.


Related in: MedlinePlus

Single subject analysis. Raw data presented across both phases. Lines represent mean (solid) and two SD (dashed) of baseline; dark gray, SMR; light gray, CTL. Cortical silent period (CSP) duration, average handwriting pressure while drawing loops, Global rating of change (GROC) scores (0, change; 1, almost the same). Improved handwriting quality after both interventions was observed while pressure remained stable. CSP suggests a decrease in excitability at both post-tests and at SMR follow-up.
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Figure 4: Single subject analysis. Raw data presented across both phases. Lines represent mean (solid) and two SD (dashed) of baseline; dark gray, SMR; light gray, CTL. Cortical silent period (CSP) duration, average handwriting pressure while drawing loops, Global rating of change (GROC) scores (0, change; 1, almost the same). Improved handwriting quality after both interventions was observed while pressure remained stable. CSP suggests a decrease in excitability at both post-tests and at SMR follow-up.

Mentions: Given the small number of patients in this study and known variable response to rTMS, a single subject analysis was also done. The benefit of single subject analysis in small n clinical studies, is that it allows for detailed analysis of within subject variability and response that is masked by group level statistics (Kimberley and Di Fabio, 2010). All subjects displayed changes in at least one measure but changes did not consistently reflect improvement in all measures with rTMS + SMR training, as hypothesized (Table 5). Two subjects in the SMR group experienced a clinically meaningful improvement in function. One subject had evidence of handwriting improvement despite only reporting a minimal change in symptoms by the GROC and no change in handwriting pressure (Figure 4).


Mixed effectiveness of rTMS and retraining in the treatment of focal hand dystonia.

Kimberley TJ, Schmidt RL, Chen M, Dykstra DD, Buetefisch CM - Front Hum Neurosci (2015)

Single subject analysis. Raw data presented across both phases. Lines represent mean (solid) and two SD (dashed) of baseline; dark gray, SMR; light gray, CTL. Cortical silent period (CSP) duration, average handwriting pressure while drawing loops, Global rating of change (GROC) scores (0, change; 1, almost the same). Improved handwriting quality after both interventions was observed while pressure remained stable. CSP suggests a decrease in excitability at both post-tests and at SMR follow-up.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4496570&req=5

Figure 4: Single subject analysis. Raw data presented across both phases. Lines represent mean (solid) and two SD (dashed) of baseline; dark gray, SMR; light gray, CTL. Cortical silent period (CSP) duration, average handwriting pressure while drawing loops, Global rating of change (GROC) scores (0, change; 1, almost the same). Improved handwriting quality after both interventions was observed while pressure remained stable. CSP suggests a decrease in excitability at both post-tests and at SMR follow-up.
Mentions: Given the small number of patients in this study and known variable response to rTMS, a single subject analysis was also done. The benefit of single subject analysis in small n clinical studies, is that it allows for detailed analysis of within subject variability and response that is masked by group level statistics (Kimberley and Di Fabio, 2010). All subjects displayed changes in at least one measure but changes did not consistently reflect improvement in all measures with rTMS + SMR training, as hypothesized (Table 5). Two subjects in the SMR group experienced a clinically meaningful improvement in function. One subject had evidence of handwriting improvement despite only reporting a minimal change in symptoms by the GROC and no change in handwriting pressure (Figure 4).

Bottom Line: Contrary to our hypothesis, group analyses revealed no additional benefit from the SMR training vs.The patient rated improvements were accompanied by a moderate effect size suggesting clinical meaningfulness.These results provide encouragement for further investigation of rTMS in FHD with a need to optimize a secondary intervention and determine likely responders vs. non-responders.

View Article: PubMed Central - PubMed

Affiliation: Program in Physical Therapy, Brain Plasticity Laboratory, Department of Physical Medicine and Rehabilitation, University of Minnesota Minneapolis, MN, USA.

ABSTRACT

Unlabelled: Though the pathophysiology of dystonia remains uncertain, two primary factors implicated in the development of dystonic symptoms are excessive cortical excitability and impaired sensorimotor processing. The aim of this study was to determine the functional efficacy of an intervention combining repetitive transcranial magnetic stimulation (rTMS) and sensorimotor retraining. A randomized, single-subject, multiple baseline design with crossover was used to examine participants with focal hand dystonia (FHD) (n = 9).

Intervention: 5 days rTMS + sensorimotor retraining (SMR) vs. Five days rTMS + control therapy (CTL) (which included stretching and massage). The rTMS was applied to the premotor cortex at 1 Hz at 80% resting motor threshold for 1200 pulses. For sensorimotor retraining, a subset of the Learning-based Sensorimotor Training program was followed. Each session in both groups consisted of rTMS followed immediately by 30 min of the therapy intervention (SMR or CTL). Contrary to our hypothesis, group analyses revealed no additional benefit from the SMR training vs. CTL. When analyzed across group however, there was significant improvement from the first baseline assessment in several measures, including tests of sensory ability and self-rated changes. The patient rated improvements were accompanied by a moderate effect size suggesting clinical meaningfulness. These results provide encouragement for further investigation of rTMS in FHD with a need to optimize a secondary intervention and determine likely responders vs. non-responders.

No MeSH data available.


Related in: MedlinePlus