Repetitive Transcranial Magnetic Stimulation (rTMS) as a Modulator of Cognitive Dysfunction in Schizophrenia: Evidence from a Nigerian Outpatient Cohort
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Keywords
Schizophrenia, Cognitive Dysfunction, Working Memory, Executive Function, rTMS
Abstract
Background: Cognitive deficits, especially in working memory and executive functioning, are central features of schizophrenia and major contributors to poor functional outcomes. Repetitive Transcranial Magnetic Stimulation (rTMS) has gained attention as a potential adjunctive intervention for these impairments. The study assessed the impact of rTMS on working memory and executive function in patients with schizophrenia attending Ahmadu Bello University Teaching Hospital (ABUTH), Shika-Zaria, Nigeria.
Methodology: A randomized, double-blind, sham-controlled trial was conducted with 250 patients diagnosed with schizophrenia. Participants were allocated to active rTMS (n = 125) or sham rTMS (n = 125). Cognitive performance was measured at baseline and after intervention using the Working Memory Index (WMI) of the WAIS-IV and the Wisconsin Card Sorting Test (WCST).
Results: A total of 238 participants (95.2%) completed the study (active rTMS = 120; sham = 118). The active rTMS group showed statistically significant improvements in working memory (mean change = +7.8; p < 0.001; Cohen's d = 0.52) and executive function (mean gain in WCST categories = +2.1; p < 0.001; Cohen's d = 0.49) compared to sham. Clinically, 45% of those receiving rTMS shifted from impaired to low-average cognitive performance, versus 9.3% in the sham group.
Conclusion: rTMS produced moderate but meaningful improvements in working memory and executive function, underscoring its potential as an adjunctive therapy for schizophrenia. These findings suggest rTMS could enhance functional outcomes, particularly in resource-constrained settings.
References
2. Adebowale TO, Ogunlesi AO. Pattern of psychiatric inpatient admissions in a Nigerian tertiary hospital. West Afr J Med. 1999;18(1):49-52.
3. World Health Organization. Global health estimates 2019: Disease burden by cause, age, sex, by country and by region, 2000–2019. Geneva: WHO; 2020.
4. Keefe RSE, Harvey PD. Cognitive impairment in schizophrenia. Handb Clin Neurol. 2012;106:377-90. doi:10.1016/B978-0-444-52002-9.00022-X.
5. Barch DM, Ceaser A. Cognition in schizophrenia: Core psychological and neural mechanisms. Trends Cogn Sci. 2012;16(1):27-34. doi:10.1016/j.tics.2011.11.015.
6. Green MF, Horan WP, Lee J. Social cognition in schizophrenia. Nat Rev Neurosci. 2015;16(10):620-31. doi:10.1038/nrn4005.
7. Harvey PD, Bowie CR. Cognition in schizophrenia: Functional importance and measurement. Am J Psychiatry. 2012;169(3):241-3. doi:10.1176/appi.ajp.2011.11111604.
8. Green MF. Impact of cognitive and social cognitive impairment on functional outcomes in schizophrenia. World Psychiatry. 2016;15(1):15-27. doi:10.1002/wps.20314.
9. Glahn DC, Ragland JD, Abramoff A, Barrett J, Laird AR, Bearden CE, et al. Beyond hypofrontality: A quantitative meta-analysis of functional neuroimaging studies of working memory in schizophrenia. Hum Brain Mapp. 2005;25(1):60-9. doi:10.1002/hbm.20138.
10. Minzenberg MJ, Laird AR, Thelen S, Carter CS, Glahn DC. Meta-analysis of 41 task-based fMRI studies of executive function in schizophrenia. Arch Gen Psychiatry. 2009;66(8):811-22. doi:10.1001/archgenpsychiatry.2009.91.
11. Keefe RSE, Bilder RM, Davis SM, Harvey PD, Palmer BW, Gold JM, et al. Neurocognitive effects of antipsychotic medications in patients with chronic schizophrenia in the CATIE trial. Arch Gen Psychiatry. 2007;64(6):633-47. doi:10.1001/archpsyc.64.6.633.
12. Hallett M. Transcranial magnetic stimulation: A primer. Neuron. 2007;55(2):187-99. doi:10.1016/j.neuron.2007.06.026.
13. Pascual-Leone A, Valls-Solé J, Wassermann EM, Hallett M. Responses to rapid-rate transcranial magnetic stimulation of the human motor cortex. Brain. 1994;117(4):847-58. doi:10.1093/brain/117.4.847.
14. Bestmann S, Baudewig J, Siebner HR, Rothwell JC, Frahm J. BOLD MRI responses to repetitive TMS over human dorsal premotor cortex. Neuroimage. 2004;23(2):628-35. doi:10.1016/j.neuroimage.2004.07.017.
15. O’Reardon JP, Solvason HB, Janicak PG, Sampson S, Isenberg KE, Nahas Z, et al. Efficacy and safety of transcranial magnetic stimulation in the acute treatment of major depression: a multisite randomized controlled trial. Biol Psychiatry. 2007;62(11):1208–16. doi:10.1016/j.biopsych.2007.01.018.
16. Guse B, Falkai P, Wobrock T. Cognitive effects of high-frequency rTMS in schizophrenia patients with predominant negative symptoms: A pilot study. Schizophr Res. 2010;116(2-3):355-6. doi:10.1016/j.schres.2009.12.013.
17. Mogg A, Purvis R, Eranti S, Contell F, Taylor JP, Nicholson T, et al. High-frequency rTMS over the left dorsolateral prefrontal cortex for negative symptoms and cognitive deficits in schizophrenia: A double-blind, sham-controlled study. Psychol Med. 2007;37(4):513-22. doi:10.1017/S0033291706009651.
18. Guse B, Falkai P, Wobrock T. Cognitive effects of rTMS in schizophrenia: A systematic review. World J Biol Psychiatry. 2010;11(7):991-1007. doi:10.3109/15622971003624197.
19. Guse B, Falkai P, Wobrock T. Cognitive effects of noninvasive brain stimulation in schizophrenia: A systematic review and meta-analysis. Schizophr Bull. 2013;39(4):pp-pp.
20. Katz C, Furtado M, Abdool PS, Gangopadhyay J, Green A, MacMaster FP. Neuromodulation in sub-Saharan Africa: Current status and challenges. Afr J Psychiatry. 2014;17(5):1-6.
21. Gureje O, Olley BO, Adebayo KO, Odejide OA. Cognitive remediation and psychosocial services in Nigerian mental health settings: Availability and gaps. Afr J Med Med Sci. 2010;39(3):233-40.
22. Adewuya AO, Ilesanmi AO, Adedeji AO, Abiodun OA. Neurocognitive deficits and functional outcomes among outpatients with schizophrenia in South-West Nigeria. Afr J Psychiatry. 2017;20(3):1-7.
23. Olagunju AT, Aina OF, Erinfolami AR, Adeyemi JD. Executive dysfunction predicts poor medication adherence and relapse in Nigerian patients with schizophrenia. Niger Postgrad Med J. 2019;26(3):170-6.
24. Seedat S, Moosa MYH, Stevens J, Williams DR. High-frequency rTMS for negative and cognitive symptoms in schizophrenia: A South African pilot. S Afr J Psychiatry. 2020;26:a1560. doi:10.4102/sajpsychiatry.v26i0.1560.
25. Kuria MW, Ndetei DM, Obondo A, Kokonya D. Cognitive deficits and functional disability in schizophrenia in Kenya: Implications for non-pharmacological interventions. East Afr Med J. 2021;98(5):265-72.
26. Barr MS, Farzan F, Rajji TK, Voineskos AN, Blumberger DM, Arenovich T, et al. Can repetitive magnetic stimulation improve working memory in schizophrenia? Biol Psychiatry. 2013;73(6):510-7. doi:10.1016/j.biopsych.2012.08.014.
27. Aleman A, Enriquez-Geppert S, Knegtering H, Dlabac-de Lange JJ. Moderate effects of non-invasive brain stimulation of the frontal cortex on negative symptoms and cognitive dysfunction in schizophrenia: A meta-analysis. Neurosci Biobehav Rev. 2018;89:111-8. doi:10.1016/j.neubiorev.2018.02.009.
28. Li X, Ma R, Pang L, Zhang T, Guo Q, Wang J. High-frequency rTMS over left DLPFC improves executive function in schizophrenia: A randomized sham-controlled trial. Psychiatry Res. 2016;240:20-5. doi:10.1016/j.psychres.2016.04.001.
29. Hasan A, Falkai P, Wobrock T, Schmitt A, Malchow B, Schneider-Axmann T, et al. Augmenting cognitive remediation with rTMS in schizophrenia: Randomized, double-blind, sham-controlled trial. Schizophr Bull. 2017;43(3):pp-pp.
30. Fett AKJ, Viechtbauer W, Dominguez M-d-G, Penn DL, van Os J, Krabbendam L. The relationship between neurocognition and social cognition with functional outcomes in schizophrenia: A meta-analysis. Schizophr Bull. 2011;37(3):573-83. doi:10.1093/schbul/sbp010.
31. Harvey PD, Keefe RSE. Studies of cognitive change in patients with schizophrenia following novel antipsychotic treatment. Am J Psychiatry. 2001;158(2):176-84. doi:10.1176/appi.ajp.158.2.176.
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Summayyah Muhammad Bashar, Department of Psychiatry, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria
Senior Registrar, Department of Psychiatry, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria
Sani Khalid, Department of Psychiatry, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria
Senior Registrar, Department of Psychiatry, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria