Multiple sessions of low-frequency repetitive transcranial magnetic stimulation in focal hand dystonia: clinical and physiological effects

TY - JOUR

T1 - Multiple sessions of low-frequency repetitive transcranial magnetic stimulation in focal hand dystonia

T2 - clinical and physiological effects

AU - Kimberley, Teresa Jacobson

AU - Borich, Michael R

AU - Arora, Sanjeev

AU - Siebner, Hartwig R

PY - 2013

Y1 - 2013

N2 - Purpose: The ability of low-frequency repetitive transcranial magnetic stimulation (rTMS) to enhance intracortical inhibition has motivated its use as a potential therapeutic intervention in focal hand dystonia (FHD). In this preliminary investigation, we assessed the physiologic and behavioral effects of multiple sessions of rTMS in FHD. Methods: 12 patients with FHD underwent five daily-sessions of 1 Hz rTMS to contralateral dorsal premotor cortex (dPMC). Patients held a pencil and made movements that did not elicit dystonic symptoms during rTMS. We hypothesized that an active but non-dystonic motor state would increase beneficial effects of rTMS. Five additional patients received sham-rTMS protocol. The area under curve (AUC) of the motor evoked potentials and the cortical silent period (CSP) were measured to assess changes in corticospinal excitability and intracortical inhibition, respectively. Behavioral measures included pen force and velocity during handwriting and subjective report. Results: Multiple-session rTMS strengthened intracortical inhibition causing a prolongation of CSP after 3 days of intervention and pen force was reduced at day 1 and 5, leaving other measures unchanged. 68% of patients self-reported as 'responders' at day 5, and 58% at follow-up. Age predicted responders. Conclusions: A strong therapeutic potential of this rTMS paradigm in FHD was not supported but findings warrant further investigation.

AB - Purpose: The ability of low-frequency repetitive transcranial magnetic stimulation (rTMS) to enhance intracortical inhibition has motivated its use as a potential therapeutic intervention in focal hand dystonia (FHD). In this preliminary investigation, we assessed the physiologic and behavioral effects of multiple sessions of rTMS in FHD. Methods: 12 patients with FHD underwent five daily-sessions of 1 Hz rTMS to contralateral dorsal premotor cortex (dPMC). Patients held a pencil and made movements that did not elicit dystonic symptoms during rTMS. We hypothesized that an active but non-dystonic motor state would increase beneficial effects of rTMS. Five additional patients received sham-rTMS protocol. The area under curve (AUC) of the motor evoked potentials and the cortical silent period (CSP) were measured to assess changes in corticospinal excitability and intracortical inhibition, respectively. Behavioral measures included pen force and velocity during handwriting and subjective report. Results: Multiple-session rTMS strengthened intracortical inhibition causing a prolongation of CSP after 3 days of intervention and pen force was reduced at day 1 and 5, leaving other measures unchanged. 68% of patients self-reported as 'responders' at day 5, and 58% at follow-up. Age predicted responders. Conclusions: A strong therapeutic potential of this rTMS paradigm in FHD was not supported but findings warrant further investigation.

U2 - 10.3233/RNN-120259

DO - 10.3233/RNN-120259

M3 - Journal article

C2 - 23340117

SN - 0922-6028

VL - 31

SP - 533

EP - 542

JO - Restorative Neurology and Neuroscience

JF - Restorative Neurology and Neuroscience

IS - 5

ER -