Abstracts

Rationale: Although both traumatic brain injury (TBI) and epilepsy are independently associated with psychiatric comorbidities, there is scanty evidence on the association of post-traumatic epilepsy (PTE) and psychiatric comorbidities. This study aimed to systematically review the evidence on psychiatric comorbidities in people with PTE.


Methods: A systematic review was conducted to look for all published studies reporting psychiatric comorbidities among people with PTE compared to those without PTE. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines. Our systematic search included records up until May 2024 in Ovid® MEDLINE, Embase®, and PsycINFO. Abstract review was performed in duplicate and data extraction was done independently using standard proforma. Studies were included if they reported prevalence and/or incidence of psychiatric comorbidities among people with PTE compared to control groups of people with i) epilepsy only, ii) TBI without epilepsy, and/or iii) no TBI and no epilepsy. Meta-analyses were conducted on studies reporting psychiatric comorbidities in PTE vs. controls, and the overall effect was reported as risk ratio (RR) with a 95% confidence interval (CI). All analyses were carried out using the 'metabin' function in R, version 4.2.1 (R Foundation for Statistical Computing).


Results: Out of a total of 994 records identified from the systematic database search, 6 were ultimately included in the study. Meta-analyses were conducted for dementia and depression. The pooled analysis of 2 population-based studies with an average of >5 years follow-up, on a total of 893 people with PTE and 4803 people with TBI-no epilepsy, showed that the incidence proportion of dementia is significantly higher in PTE than in TBI-no epilepsy (96/893 [10.7%] vs. 544/4803 [11.3%]; RR: 1.99 95% CI: 1.02-3.86, p-value=0.04; I²=88%, τ²=0.20; Figure 1). On the contrary, a pooled analysis of 2 studies comparing 1-year follow-up results in 81 people with PTE and 515 people with TBI-no epilepsy showed that the incidence proportion of depression is not significantly different between PTE and TBI-no epilepsy (24/81 [29.6%] vs. 121/515 [23.4%]; RR: 1.20 95% CI: 0.83-1.74, p-value=0.33; I²=0%, τ²=0; Figure 2).


Conclusions: This is the first systematic review exploring psychiatric comorbidities in PTE compared with any control group. The evidence on this topic is enormously limited so we were only able to compare the incidence of dementia and depression in PTE and TBI-no epilepsy. Our findings indicated a significantly higher risk of dementia in PTE vs. TBI-no epilepsy, whereas no such an association was observed for depression. We highly recommend future longitudinal studies to be performed to explore psychiatric comorbidities in PTE and to compare to TBI-no epilepsy, and/or epilepsy only, and/or otherwise healthy controls.


Funding: This study received no funding.