Table 3. Two time-point comparison of percentage change in brain atrophy measurements and lead measurements.

	3rd Ventricle Width	Evans index	Ventricular Index	Cella Media Index	Δ AP	Δ Lateral	Δ Axial
Patient 1	300%	5.7%	7.5%	5.5%	0.32	1.2	0.16
Patient 2	37.3%	9.4%	6.6%	15.1%	0.1	2.68	0.5
Patient 3	22.5%	4.1%	1.1%	29.1%	0.52	1.88	0.26
Mean	120%	6%	5%	17%	-	-	-

Change in lead position was measured using a distance formula: √ (X_pre−X_post)²+(Y_pre−Y_post)²+(Z_pre−Z_post)². AP = antero-posterior.