Alisson Paulino Trevizol＊, Quirino Cordeiro

Psychiatry Department, Santa Casa School of Medical Sciences, S?o Paulo, Brazil

Interdisciplinary Laboratory of Clinical Neurosciences (LINC),Department of Psychiatry, Federal University of S?o Paulo(UNIFESP), S?o Paulo, Brazil

The article entitled “Effects of ultra-low frequency transcranial magnetic stimulation on motor function and intelligence of children with spastic cerebral palsy: study protocol for a randomized parallel-cohort controlled trial” by Feng et al. (2016) describes a randomized, single-blinded clinical trial for evaluation of repetitive transcranial magnetic stimulation (rTMS) for gross and fine motor functions and intelligence in children aged 2-4 years old.

Cerebral palsy is a permanent disorder that appears in early childhood and is characterized by disturbances of the movement and posture that are attributed to brain injury during fetal development or infancy. Patients with cerebral palsy may also present cognitive impairment. The objective of cerebral palsy management is to ameliorate physical and cognitive symptoms. Therefore, neuromodulation techniques that modulate cortical excitability and function,may be used for this purpose. rTMS is a non-invasive neuromodulation therapy based on electromagnetic induction,in which electric pulses are generated via an electromotive force across a coil (conductor) exposed to time-varying magnetic fields, used to modulate cortical excitability,enabling a non-painful localized stimulation of the brain cortex. The magnetic pulses, created over the scalp by the coil, induces an electric current on the brain cortex without major dissipation on scalp and cranial structures, with enough magnitude and density to promote brain neurons depolarization at adjacent areas (George et al., 2013). The ef ficacy of rTMS has been demonstrated in meta-analysis studies for various neurological and psychiatric conditions in the adult population (Radhu et al., 2013; Enokibara et al.,2016; Trevizol et al., 2016a, b), with guidelines regarding safety well established. However, few studies on rTMS for children have been conducted, partially due to the risk of adverse effects on neurodevelopment and seizures.

Investigations on the use of rTMS for cerebral palsy are on the initial steps of development. Valle et al. (2007) have reported their findings of a randomized, double-blinded,sham-controlled, parallel design clinical trial in which patients were distributed into three groups for either 5 Hz,1 Hz or sham rTMS stimulation over the motor cortex.The study reported bene fits of rTMS for spasticity, with no seizures observed. However, the authors acknowledge the absence of a long-lasting evaluation, but the positive results encourage further evaluation of the effects of rTMS for cerebral palsy. Moreover, it is important to note that data on ultra-low frequency for cerebral palsy and spastic quadriplegia is scant and further evaluations are necessary.

The present study described by Feng et al. (2016) is noteworthy for its evaluation of rTMS with a frequency effect not only for gross and fine motor functions, but also for a cognitive measure, which is a concern for the population studied. In addition, patients will be evaluated 1 and 3 months after treatment, enabling the evaluation of longlasting effects of rTMS. Moreover, the presented protocol will add information on safety regarding cognition and adverse effects in the pediatric population. Previous studies have shown that ultra-low rTMS is safer and more reliable than conventional stimulation, an important issue for the present protocol that will be performed in children (Anand and Hotson, 2002).

In summary, few studies on rTMS for cerebral palsy have been performed and reports on the effects of rTMS for physical and cognitive symptoms are still necessary. Feng et al. (2016) described a study that can provide new directions for further studies with non-invasive brain stimulation for cerebral palsy. However, in the future, a sham group should be added to compare the clinical outcomes.

Anand S, Hotson J (2002) Transcranial magnetic stimulation: neurophysiological applications and safety. Brain Cogn 50:366-386.

Enokibara M, Trevizol A, Shiozawa P, Cordeiro Q (2016) Establishing an effective TMS protocol for craving in substance addiction:is it possible? Am J Addict 25:28-30.

Feng JY, Shan L, Wang B, Jia FY (2016) Effects of ultra-low frequency transcranial magnetic stimulation on motor function and intelligence of children with spastic cerebral palsy: study protocol for a randomized parallel-cohort controlled trial. Asia Pac Clin Transl Nerv Syst Dis 1:25-30

George MS, Taylor JJ, Short EB (2013) The expanding evidence base for rTMS treatment of depression. Curr Opin Psychiatry 26:13-18.

Radhu N, de Jesus DR, Ravindran LN, Zanjani A, Fitzgerald PB,Daskalakis ZJ (2013) A meta-analysis of cortical inhibition and excitability using transcranial magnetic stimulation in psychiatric disorders. Clin Neurophysiol 124:1309-1320.

Trevizol AP, Barros MD, Silva PO, Osuch E, Cordeiro Q, Shiozawa P (2016a) Transcranial magnetic stimulation for posttraumatic stress disorder: an updated systematic review and meta-analysis.Trends Psychiatry Psychother 38:50-55.

Trevizol AP, Shiozawa P, Cook IA, Sato IA, Kaku CB, Guimar?es FB, Sachdev P, Sarkhel S, Cordeiro Q (2016b) Transcranial magnetic stimulation for obsessive-compulsive disorder: an updated systematic review and meta-analysis. JECT doi: 10.1097/YCT.0000000000000335

Valle AC, Dionisio K, Pitskel NB, Pascual-Leone A, Orsati F, Ferreira MJ, Boggio PS, Lima MC, Rigonatti SP, Fregni F (2007)Low and high frequency repetitive transcranial magnetic stimulation for the treatment of spasticity. Dev Med Child Neurol 49:534-538.