Table 5B.

Diffusion-tensor images.

Study objectives	Participants			Results	References
	PD ICD/RBDs	PD No ICD/RBDs	Controls
To assess brain white matter tract alterations in PD+ punding vs. controls and PD ICD, and PD non-ICD	PD + Punding	PD Punding –	X	Greater damage of genu of corpus callosum and left pedunculopontine tract in PD-punding vs. PD-without ICD	(93)
To assess brain structural and functional alterations in patients with PD-ICB vs. with controls and PD no-ICB cases.	x	x	x	Cortical thinning in left pre-central and superior frontal cortices, as well as decreased Fractional anisotropy (FA) of the left uncinate fasciculus and parahippocampal tract; increased mean, radial and axial diffusivity of the left parahippocampal tract and right pedunculopontine tract; increased mean and radial diffusivity of the genu of the cingulate cortex and right uncinate fasciculus.	(86)
To determine the changes in DTI associated with medication-related ICD in PD patients undergoing chronic dopamine-replacement therapy.	x	x	x	PD-ICD showed significantly elevated FA in anterior cingulate cortex (ACC), right internal capsule posterior limbs, right posterior cingulum, and right thalamic radiations compared to PD-without ICD	(92)
To identify alterations of white matter tract in drug-naïve PD- ICDs	x	x	x	Decreased connectivity in left and right cortico-thalamic tract, left and right cortico-pontine tract, left and right corticospinal tract, left and right superior cerebellar peduncle and left and right middle cerebellar peduncle between PD-ICD compared to PD-without ICD. Decreased connectivity in left and right inferior longitudinal fasciculus, genu and body of corpus callosum, left and right corticospinal tract, left superior cerebellar peduncle and left and right cingulum in PD-ICD compared to control.	(94)

Modified by: Ramdave et al. (81) and Meyer et al. (82).