Transcranial Random Noise (tRNS) for BPSD in Alzheimer's Disease: A Double-blind Randomized Controlled Trial

All patients underwent a medical evaluation that included physical examination and routine laboratory studies before and after Transcranial random noise (tRNS) treatment. Upon meeting the inclusion criteria and providing informed consent, each participant will complete a series of cognitive assessments and tRNS treatments at the First Affiliated Hospital of AnHui medical university. Patients were randomly allocated to tRNS group and the sham group. There are about 20 patients in each group. For the all patients, allocation was by coin toss. Patients were studied using a double-blind design. Study participants, clinical raters, and all personnel responsible for the clinical care of the patient remained masked to allocated condition and allocation parameters. Only tRNS administrators had access to the randomization list; they had minimal contact with the patients, and no role in cognitive and synptom assessments. Each patient would be treated for continuous 14 days by tRNS. The stimulation electrodes were arranged in a 4 × 1 ring at AFz, FCz, F7, C5 and F3, with the central electrode producing a random alternating current of 1.5ma and the surrounding 4 electrodes producing 1/4 of the current of the central electrode. At 100-640 Hz tRNS, participants had a mean interpeak-to-peak stimulation intensity of 1.5mA. Under the sham conditions, 100-640 Hz tRNS were delivered only during the ascent and descent phases (30 seconds); No current was transmitted during the 30-minute intervention. The tRNS stimulation lasted for 30 minutes, which is common in cognitive neuroscience research.

Before the tRNS treatment, a series of cognitive assessments and neuropsychological tests were obtained by a trained investigator to assess baseline. Each assessment will involve a set of assessment tools, the associative memory as the primary outcome measure and various other tasks and questionnaires to measure cognition(including MoCA,MMSE, DS, Stroop test, TMT, BNT-30, VFT, CDT,JLOT. Form H,HVOT), memory (CAVLT, LMT), emotion(HAMA-17,HAMD-14,GDS-30), behavioral and psychological symptoms(NPI), and treatment tolerability. All the tests are conducted in two days. The patient received resting EEG data collection. After the last treatment, the MoCA, and associative memory were obtained, as well as the Global Index of Safety to assess adverse events of the treatment. Patients were instructed to focus their answers on the past 14 days. The patients had also receiving a battery measure of neuropsychological tests, resting EEG. Two month after the last treatment, participants were interviewed to obtain the same assessment as before. They were instructed to focus their answers on the past months.