Triple stimulation technique to evaluate the curative effect of repetitive transcranial magnetic stimulation in patients with multiple system atrophy: two cases report

Abstract

Background Previous studies suggest that the cortico-spinal tract can be modulated by M1 repetitive transcranial magnetic stimulation (rTMS). However, it is not well investigated in patients with multiple system atrophy (MSA). We discuss 2 cases of MSA with parkinsonism-predominant (MSA-P), who have been evaluated the function of cortico-spinal tract using triple stimulation technique (TST) before and after rTMS, so as to explore the effect of rTMS on improving the damage of cortico-spinal tract.  Methods Two MSA-P patients (one 62-year-old male, one 44-year-old female) with disease course of one year were examined with TST at abductor digiti minimi. TST amplitude ratio and the motor score of Unified Multiple System Atrophy Rating Scale (UMSARSⅡ) were used to assess the damage of cortico-spinal tract and motor function before and after rTMS treatment.  Results TST amplitude ratio at abductor drgiti minimi of both patients was 28.30% and 69.10%, and UMSARS Ⅱ score was 22 and 20 before treatment. Immediately after rTMS the amplitude ratio was 58.40% and 71.70% , and UMSARS Ⅱ score was 16 and 12, respectively. The improvement sustained in Case one in the next month (TST amplitude ratio 90.70% , UMSARS Ⅱ score 17) and the second month (TST amplitude ratio 50.70% , UMSARS Ⅱ score 23).  Conclusions TST can be used to quantitatively evaluate the integrity of cortico-spinal tract after rTMS.

DOI: 10.3969/j.issn.1672-6731.2017.06.008