Effects of Transcranial Direct Current Stimulation on the Apathy of Alzheimer's Disease

Effects of Transcranial Direct Current Stimulation on the Apathy of Alzheimer's: a Randomized, Sham-controlled Clinical Trial

This is a phase 2 double-blind, randomized, sham-controlled study to investigate the effects of repeated transcranial direct current stimulation for the treatment of apathy in moderate Alzheimer's Disease in patients selected from an outpatient clinics in São Paulo, Brazil.

Forty patients were randomized to receive either active or sham-tDCS over the left dorsolateral prefrontal cortex (DLPFC). Patients received six sessions of intervention during two weeks and were evaluated at baseline, at week one and two, and after one week without intervention. Clinical raters, patients, and caregivers were blinded. The primary outcome was apathy. Global cognition and neuropsychiatric symptoms were examined as secondary outcomes.

Inclusion criteria:

1. Dementia defined by DSM-IV (Diagnostic and Statistical Manual version IV)
2. Possible Alzheimer's Disease defined by NINCDS-ADRDA (National Institute for Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association)
3. Mini Mental State Examination scores from 10 to 20
4. Apathy defined by a score equal or higher to 14 in Apathy Scale

Exclusion criteria:

1. Clinical instability
2. Epilepsy
3. Metallic clip in the head
4. Use of alcohol and psychotropic drugs