Deep Transcranial Magnetic Stimulation (dTMS) for Mild Cognitive Impairment: A Proof of Concept Study.

Introduction - Minor Neurocognitive Disorder (mNCD), formerly known as Mild Cognitive Impairment (MCI), refers to supra-physiological cognitive decline that affects the quality of life but not enough to be classified as Dementia. In line with the limited understanding of the disease, the treatment alternatives are also limited, with only a handful of alternatives showing some promise in preserving cognition. Recently, non-invasive neuromodulation has been explored for its potential benefit in MCI. Stimulation of the dorsolateral prefrontal cortex by repetitive Transcranial Magnetic Stimulation (rTMS) has been found to improve cognitive function. However, the currently available figure-8 coil rTMS systems have limited the application of TMS in MCI due to low penetration. Roth et al. reported that the H-coil directly stimulates the lateral and medial regions of the PFC at depths of up to 3 cm using low power, effectively addressing the depth restrictions associated with conventional rTMS that employ figure-8 coils. Here, we aim to systematically evaluate the efficacy and safety of Deep TMS (dTMS) in patients with MCI.

Methodology - Patients with Mild Cognitive Impairment (MCI) as per DSM-5, eligible for dTMS (based on Brainsway™ guidelines), will be approached to participate in the study. After enrollment in the study, the demographics, clinical history, and cognitive function will be assessed. Cognitive function of the patient will be assessed using MoCA, Clinical Dementia Rating Scale (CDR), Alzheimer’s Disease Assessment Scale - Cognitive subscale, adapted for use in MCI (ADAS-cog/MCI), Alzheimer’s Disease Cooperative Study Activities of Daily Living adapted to MCI (ADCS-ADL/MCI), Delayed Recall Score of the NYU Paragraph Recall Test, and Addenbrooke Cognitive Examination (ACE). Participants will then be randomized into two groups: dTMS and sham-control. The dTMS group will receive 20 sessions of TMS with a Brainsway™ H7 coil, while the sham-controlled group will undergo a dummy paradigm resembling the treatment protocol using the H7 coil. At the end of the treatment, cognitive ability will be assessed again.