Apathy and Reduced Speed of Processing Underlie Decline in Verbal Fluency following DBS

Table 6

Letter and category fluency characteristics pre- and post-DBS.

	Letter fluency (F, A, S)			Category fluency (animals)
	Pre-DBS	Post-DBS	p	Pre-DBS	Post-DBS
Words: 0–15 s	18.13 ± 6.14	16.07 ± 6.53	.06^a	15.67 ± 3.75	14.13 ± 5.04	.15^a
Words: 16–60 s	27.73 ± 11.46	28.07 ± 15.17	.87^a	27.20 ± 9.13	23.13 ± 9.09	.04^a
Cluster size	3.31 ± 2.14	2.98 ± 1.55	.50^a	1.27 ± 0.88	1.59 ± 1.01	.29^b
Number of switches	23.68 ± 14.29	21.18 ± 12.37	.32^a	8.86 ± 6.92	7.27 ± 4.71	.28^a
Total errors	2.68 ± 2.23	1.64 ± 1.59	.05^a	0.77 ± 1.06	0.55 ± 0.96	.50^b

Results are given as mean ± SD (^apaired t-test, ^bWilcoxon signed-rank, ).