rTMS and Botulinum Toxin in Benign Essential Blepharospasm

University of Florida

Status: Completed

Conditions: Benign Essential Blepharospasm

Treatments: Device: Sham Magstim RapidStim2; Device: Magstim RapidStim2

Study type: Interventional

Funder types: Other

Identifiers

NCT02370875

201400993

Details and patient eligibility

About

Benign essential blepharospasm (BEB) is a functionally disabling focal dystonia. Botulinum neurotoxin (BoNT) therapy is suboptimal in many BEB patients. Repetitious transcranial magnetic stimulation (rTMS) therapy is a promising noninvasive therapy and has shown positive benefits in BEB. rTMS therapy can be easily combined with BoNT injections to enhance the effects of BoNT in BEB.

Full description

A two week course of rTMS therapy to achieve sustained benefits will be employed. With standard BoNT treatment, the peak-dose benefits are seen at about 4-6 weeks after the administration of injections. rTMS will be introduced during this peak-dose period (about 6 weeks after BoNT or T1).The effects of combined therapy at about 10 weeks after BoNT injections (T2) and at about 12 weeks after BoNT injections (T3) will be examined along with the physiological effects at these time points.

Enrollment: 12 patients

Sex: All

Ages: 30 to 75 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• subjects diagnosed with blepharospasm or cranio-cervical dystonia who receive BoNT therapy at the Center for Movement Disorders will be approached. The investigators will enroll only those subjects who report experiencing positive benefits with BoNT but lasting about 10 weeks or less.

Exclusion criteria

• pregnancy
• active seizure disorder
• significant cognitive impairment
• exposure to neuroleptics
• presence of a metallic body such as pacemaker, implants, prosthesis, artificial limb or joint, shunt, metal rods and hearing aid.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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12 participants in 2 patient groups

Real rTMS stimulation

Experimental group

Description:

Repetitious transcranial magnetic stimulation (rTMS) will be delivered using the Magstim RapidStim2 over each anterior cingulate cortex, using a figure-of-eight coil. The investigators will apply rTMS with 0.2 Hz frequency to the ACC. 180 stimuli will be delivered with a stimulator output of 100% active motor threshold (AMT). AMT will be assessed at the tibialis anterior muscle with the coil. The AMT will be defined as the lowest stimulation intensity required to evoke a 150 μV potential in the target muscle. To determine the stimulation site for ACC, the coil will be placed over Fz and then moved over the midline of the brain in 0.5-cm steps anteriorly, until the point of maximum motor evoked potential in the orbicularis oculi (OO) muscle. The coil position will be marked on the skin. These rTMS sessions will be repeated daily for 10 days.

Treatment:

Device: Magstim RapidStim2

Sham rTMS Stimulation

Sham Comparator group

Description:

During sham repetitious transcranial magnetic stimulation (rTMS), subjects will undergo the same procedure for identifying stimulus location as used in patients receiving real rTMS using the sham Magstim RapidStim2 coil. This coil will be placed on the patient's head in an identical manner however will not be connected to the Magstim device. Instead another coil will be connected to provide stimulation sound. In each stimulation condition, the Magstim will be placed behind the patient and not visible to him or her. Placebo sham coil which produces discharge noise and vibration similar to a real coil without stimulating the cerebral cortex. During rTMS, all patients will continue to wear ear plugs as instructed during the real stimulation sessions.

Treatment:

Device: Sham Magstim RapidStim2