Cognitive Impact of Deep Brain Stimulation on Parkinson’s Disease Patients

Table 2

Studies assessing cognitive change in PD patients after GPi DBS.

Author, year	N	F/u (mo)	Controlled	Status of stimulation/medication at cognitive assessment	Improved cognitive measure(s)	Worsened cognitive measure(s)	Unchanged cognitive measure(s)
Ardouin et al., 1999 [25]	13	3–6	No	ON/inconsistent	E	L	GC, E, PS
Jahanshahi et al., 2000 [63]	6	12	No	ON and OFF/OFF	None	None	E, A/C, PS, M,
Pillon et al., 2000 [60]	13	12	No	ON and OFF/75% OFF	None	None	E, PS, L, M
Trépanier et al., 2000 [87]	4	6	No	ON/ON	None	None	A/C, M, V, L, E
Rothlind et al., 2007 [50]	14	21	No	ON/ON	None	L	A/C, E, L, V, M
Fields et al., 1999 [74]	6	5	No	ON/ON	M	None	GC, E, A/C, V, L, M
Tröster et al., 1997 [66]	9	3	No	ON/ON	None	V, L	GC, E, A/C, V, M, L
Tröster et al., 2017 [35]	136	12	No	ON/not specified	None	L, A/C	GC, A/C, E, M
Vingerhoets et al., 1999 [76]	20	3	No	ON/ON	None	None	M, V, E, PS
Rothlind et al., 2015 [47]	80	6	Yes	ON/ON	None	E, A/C	E, M, A/C, L, PS

PD: Parkinson’s disease; GPi: globus pallidus interna; N: number of patients; mo: months; A/C: attention/concentration; E: executive; GC: global cognition; L: language; M: memory; PS: psychomotor/processing speed; V: visual. Note. Multiple tests were performed for each domain in each study, and often a few of these showed a difference while other tests assessing the same domain did not. This explains why the same domain might appear more than once and under different results for the same study. Adapted from Mehanna [101] with permission from the author.