iTBS Study for Depression in Patients With Multiple Sclerosis

Multiple sclerosis (MS) is a chronic and demyelinating disease of the central nervous system. It is one of the most common cause of neurological disability in young adults. Depression is a common symptom in MS patients, with lifetime prevalence rates going up to 50%. Depression not only reduces the response to treatment, delays the recovery of neurological function and social ability, but also significantly increases the risk of disability in patients with MS. It is worth noting that depression remains widely underdiagnosed and untreated in MS patients. The investigators aim to treat the depression in MS patients using a non-invasive method, which will help improve life quality and reduce the risk of disability in patients. Transcranial magnetic stimulation (TMS) is a non-invasive method of brain stimulation that uses magnetic fields to stimulate nerve cells in brain. Repetitive TMS (rTMS) is usually applied in antidepressant-resistant depression. Furthermore, some clinical trials show that rTMS also significantly improve Parkinson's related depression and postpartum depression. Intermittent theta burst stimulation (TBS), a newer form of rTMS, delivers 600 pulses in just 3 min, versus 37.5 min for conventional rTMS, but it has been shown to produce similar effects in patient with treatment-resistant depression. In this study, thirty patients who meet the criteria will be included. They will then be randomly assigned into the SHAM or iTBS group for the study intervention. Patients and outcome assessors will be masked to treatment allocation. SHAM or iTBS will be delivered to stimulate left dorsalateral prefrontal cortex (DLPFC). The protocol includes 600 pulses per session: triplet 50 Hz bursts, repeated at 5 Hz; 2 s on and 8 s off. Each patient will receive 2 sessions per day over a period of 10 days (total of 20 sessions). After the treatment phase, patients will be followed up once after two weeks. The presence and severity of side effects will be assessed by the physician from the Department of Neurology. Before and after the iTBS or SHAM intervention and after two weeks of follow-up, primary and secondary measurements will be performed. Results of this study will inform on the efficiency of the TMS for the treatment of depression in MS patients, which will reduce the risk of disability and improve the quality of life.