Adjunctive treatment with high frequency repetitive transcranial magnetic stimulation for the behavioral and psychological symptoms of patients with Alzheimer's disease: a randomized,double-blind,sham-controlled study

Background

Behavioral and psychological symptoms of dementia (BPSD) occur in 70-90% of patients at different stages of Alzheimer’s Disease (AD), but the available methods for managing these problems are of limited effectiveness.

Aim

Assess the effects of high-frequency repetitive transcranial magnetic stimulation (rTMS), applied over the left dorsolateral prefrontal cortex (DLPFC), on BPSD and cognitive function in persons with AD.

Methods

Fifty-four patients with AD and accompanying BPSD were randomly divided into an intervention group (n=27) and a control group (n=27). In addition to standard antipsychotic treatment, the intervention group was treated with 20Hz rTMS five days a week for four weeks, while the control group was treated with sham rTMS.The Behavioral Pathology in Alzheimer''s Disease Rating Scale (BEHAVE-AD), the Alzheimer''s Disease Assessment Scale-Cognitive (ADAS-Cog), and the Treatment Emergent Symptom Scale (TESS) were administered by raters who were blind to the group assignment of patients before and after four weeks of treatment.

Results

Twenty-six subjects from each group completed the study. After four weeks of antipsychotic treatment with adjunctive real or sham rTMS treatment, the mean (sd) total BEHAVE-AD scores and mean total ADAS-Cog scores of both groups significantly decreased from baseline. After adjusting for baseline values, the intervention group had significantly lower scores (i.e., greater improvement) than the control group on the BEHAVE-AD total score, on five of the seven BEHAVE-AD factor scores (activity disturbances, diurnal rhythm, aggressiveness, affective disturbances, anxieties and phobias), on the ADAS-Cog total score, and on all four ADAS-Cog factor scores (memory, language, constructional praxis, and attention). The proportion of individuals whose behavioral symptoms met a predetermined level of improvement (i.e., a drop in BEHAVE-AD total score of > 30% from baseline) in the intervention group was greater than that in the control group (73.1% vs.42.3%, X²=5.04, p=0.025).

Conclusion

Compared to treatment of AD with low-dose antipsychotic medications alone, the combination of low-dose antipsychotic medication with adjunctive treatment with high frequency rTMS can significantly improve both cognitive functioning and the behavioral and psychological symptoms that often accompany AD.