Study of Sequentially Applied Repetitive Transcranial Magnetic Stimulation in Obsessive- Compulsive Disorders

A Randomized, Controlled Study of Sequentially Applied Repetitive Transcranial Magnetic Stimulation in Obsessive- Compulsive Disorders

The purpose of study was to investigate possible therapeutic effects and safety of sequentially combined low-frequency repetitive transcranial magnetic stimulation (rTMS) to the right dorsolateral prefrontal cortex (DLPFC) and supplementary motor area (SMA) in patients with treatment-resistant obsessive-compulsive disorder (OCD).

Obsessive-compulsive disorder (OCD) is a relatively common psychiatric disorder characterized by repetitive, intrusive thoughts and time-consuming behavioral or mental acts. Many OCD patients who do not respond to conventional treatments experience severe distress and disruptions in their daily activities. Novel approaches including psychopharmacological therapy and surgical techniques for treatment-resistant OCD have been proposed. With recent advances in non-invasive technique for stimulating the cerebral cortex, repetitive transcranial magnetic stimulation (rTMS) has been proposed as a potential therapeutic approach for various psychiatric illnesses including OCD.

Because of contradictory findings and a lack of controlled trials in OCD, rTMS cannot be yet recommended as routine therapy for OCD. However, it may have a potential clinical effect as a putative add-on treatment for OCD and an alternative therapy for treatment-resistant OCD.

For useful clinical applications, it is very important to develop methods to enhance the efficacy of rTMS. There are a number of putative ways to do this, and one of them is sequentially combining two forms of stimulation which are considered to have potential therapeutic effects. More recently, the sequential application of two stimulation regimens (high-frequency left-side rTMS and low-frequency right-side rTMS to the prefrontal cortex) has been found to have a substantial therapeutic effect in patients with treatment-resistant major depression. Therefore, the investigation for a sequentially combining effect of both the right prefrontal and the SMA stimulation would be worthwhile in OCD patients.

Inclusion Criteria:

• OCD patients who had failed adequate trials (a lack of at least a 25% reduction in the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) 15 after at least eight weeks of treatment) of at least two serotonin re-uptake inhibitors (SRI) and behavioral therapy.

Exclusion Criteria:

• Subjects were excluded if:

  • they presented with a movement disorder other than a tic
  • any psychotic symptoms
  • other anxiety disorders
  • mental retardation
  • alcohol or other substance abuse within the last six months
  • a history of psychosurgery, encephalitis or significant head trauma