Table 3.

Summary of different mechanistic pathways by which DBS affects AD and PD, as well as their consequent physiological outcomes.

Disease	Action of DBS	Physiological Effects	Year	Author	References
AD	Neuronal activation through Fornix DBS.	Increased hippocampal volume.	2020, 2012, 2019, 2015	Jakobs, Smith, Aldehri, Sankar	[142,143,144,156]
	Increased acetylcholine levels using NBM DBS.	Increased glucose uptake in amygdalo-hippocampal, temporal, and superior lingual gyrus.	2021, 2014	Maltête, Kuhn	[38,145]
	Increased prefrontal glucose uptake.	Decreased clinical decline.	2021	Lam	[146]
PD	Neuronal inhibition.	Depletion of glutamate and release of GABA and adenosine.	2012, 2001, 2001	Lozano, Contreras, Wu	[92,93,94]
	Neuronal activation.	Increased glutamate and dopamine levels.	2013, 2005, 1992	Lozano, Stefani, Benazzouz	[92,96,97]
	Neuronal activation and inhibition.	Decoupling of the soma and axons.	2013	Lozano	[92]
	Disrupt pathologic oscillatory patterns.	Neurotrophin release and generation of new neurons.	2013, 2010	Lozano, McIntyre	[92,98]