The central premise of the research study is that cholinergic system changes in specific neural network regions underlie cognitive fluctuations in patients with LBD. The cingulo-opercular task control (COTC) neural network is believed to play a role in maintenance of alertness but this remains uncertain in LDB. This critical knowledge gap forms the basis of our first aim. The study proposes to use transcranial direct current stimulation (tDCS) to excite critical cholinergic denervation components of the COTC as an adjunct to cholinergic pharmacotherapy in a target engagement study. tDCS is an emerging non-invasive neurostimulation technology that may improve a range of neurological symptoms, including cognition. The study will evaluate whether target engagement by tDCS excitation of cholinergic denervated COTC hubs may affect cognitive fluctuations in LBD subjects.
Fluctuations in alertness are very common in persons with Lewy body dementias and are a major source of disability. Changes in a chemical messenger molecule called acetylcholine within certain brain regions may play a role in these fluctuations. We propose to test this hypothesis and also determine whether a non-invasive way of stimulating affected brain regions may be of relevance for future management of these fluctuations.