TABLE 1.
Summary of the main information present in the selected articles
| AUTHORS | TYPE OF STUDY | SAMPLE SIZE (N) | STROOP TEST RESULTS |
|---|---|---|---|
| Tröster et al17 | Randomized study | Total: 136; DBS: 101; control: 35 | Declines in verbal fluency, processing speed, attention, and working memory. Greater decline in DBS patients. |
| Demeter et al24 | Case-control study | Total: 20; DBS: 10; control: 10 | There was a significant difference in semantic fluency between the two groups. |
| Bouwyn et al1 | Cohort study | Total: 100; <65 years old: 57; >65 years old: 34 | Significant decrease in verbal fluency tasks and increased interference time. The time to complete the task was longer in older participants. |
| Ardouin et al23 | Cohort study | Total: 62 | Participants’ performance in Stroop was similar before and after DBS. |
| Witt et al29 | Cohort study | Total: 23 | DBS patients committed more errors in the condition of Stroop interference. |
| Witt et al21 | Randomized study | Total: 123; DBS: 60; medication: 63 | The DBS group had negative results in interference Stroop task and number of errors. |
| Jahanshahi et al30 | Cohort study | Total: 13 | There was no significant difference in interference task. In control task (color), the patients with DBS were more rapid and presented a good number of self-corrections. Difference between STN and GPi. |
| Klempírová et al31 | Cohort study | Total: 19 | Significant worsening of Stroop performance after DBS. |
| Acera et al12 | Cohort study | Total: 97; DBS: 50; control: 47 | The patients did not show impairment in Stroop after DBS. |
| Sáez-Zea et al25 | Cohort study | Total: 36; DBS: 21; control: 12 | There was no difference between the two groups. Slight worsening of fluency and color naming in Stroop in STN group. |
| Alegret et al26 | Cohort study | Total: 16; DBS: 9; medication: 7 | Significant worsening of verbal fluency in DBS group. After 1 year, all but 1 participant presented decline in Stroop in relation to the initial performance. |
| Haegelen et al3 | Cohort study | Total: 71; GPi: 29; STN: 42 | Stroop results in both groups suggested stability. |
| Heo et al20 | Cohort study | Total: 46 | After DBS there was significant delay in word reading. After 1 year, delay in all Stroop tasks. |
| Witt et al22 | Randomized study | Total: 62; DBS: 31; medication: 31 | No significant correlation was found in neuropsychological aspects. |
| Yamanaka et al13 | Cohort study | Total: 30 | Significantly lower scores 1 month after STN. Recovered levels of performance 12 months after STN. |
| Hummelová et al33 | Cohort study | Total: 46 | Significant decline in executive functions from Stroop. |
| Odekerken et al34 | Randomized study | Total: 114; GPi: 58; STN: 56 | Significant differences in word reading and color naming in Stroop in STN individuals, showing greater negative change in relation to GPi. |
| Tramontana et al18 | Randomized study | Total: 30; medication: 15; DBS + medication: 15 | In the first year after DBS, ODT group had better result in Stroop. There was no significant difference after 24 months. |
| Kim et al19 | Cohort study | Total: 36 | Decline in the performance of the participants in Stroop was observed 36 months after surgery. |
| Kim et al35 | Cohort study | Total: 89 | There was no significant difference in Stroop performance before and after surgery. |
| Witt et al28 | Randomized study | Total: 119; DBS: 60; medication: 59 | The participants who had impaired Stroop performance also had high MDRS scores. |
| Gill et al36 | Randomized study | Total: 30; medication: 15; DBS + medication: 15 | The participants described in the study did not show significant changes in Stroop after DBS. |
| Boel et al27 | Randomized study | Total= 128; GPi= 65; STN: 63 | There was no significant difference in ST performance between the groups or over time. |
| Odekerken et al37 | Randomized study | Total= 128; GPi: 65; STN: 63 | There was no significant difference in Stroop performance between the groups or over time. |
| Le Goff et al38 | Cohort study | Total: 59 | Most of the participants increased the time in the Stroop task, suggesting executive dysfunctions. |
| Lefaucheur et al39 | Cohort study | Total: 18 | In general, there was no performance decline in Stroop after DBS. |
| Bocková et al40 | Case-control study | Total: 8 | Stroop was performed for preoperative screening. There was no sign of cognitive decline. |
| Smeding et al41 | Cohort study | Total: 145; STN: 105; control: 40 | 12 months after surgery, DBS group presented significant decline in Stroop score, compared to the control group. |
| Williams et al14 | Randomized study | Total: 37; STN:19; medication: 18 | STN group showed decline in Stroop score in 2 years, when compared to the other group. |
| Weaver et al42 | Randomized study | Total: 225; DBS: 121; medication: 134 | No intervention was associated with significant changes in Stroop score. |
| York et al15 | Cohort study | Total: 50; DBS: 23; control: 27 | DBS group obtained worse performance in Stroop Word. Both groups declined in semantic fluency. |
| Rothlind et al43 | Randomized study | Total: 42; GPi: 23; STN: 19 | Decline in Stroop score was observed after STN, compared to GPi. |
| Smeding et al16 | Cohort study | Total: 135; DBS: 99; control: 36 | DBS group showed significant decline in Stroop score when compared to control. |
| Morrison et al44 | Cohort study | Total: 28; STN: 17; control: 11 | Control group obtained better performance than DBS group in Stroop. |
| Alegret et al26 | Cohort study | Total: 15 | Low performance in Stroop was evidenced 3 months after surgery. |
DBS: Deep brain stimulation; STN: subthalamic nuclei; GPi: globus pallidus interna; MDRS: Mattis Dementia Rating Scale; ODT: optimal drug therapy; ST: Stroop test