Pediatric traumatic brain injury and early age multiple sclerosis in Finland: A nationwide register-based cohort study

OBJECTIVE

Examine the link between pediatric traumatic brain injury (pTBI) and early-onset multiple sclerosis in Finland.

METHODS

Conducted nationwide register study (1998-2018) with 28,750 pTBI patients (< 18) and 38,399 pediatric references with extremity fractures. Multiple sclerosis diagnoses from Finnish Social Insurance Institution. Employed Kaplan-Meier and multivariable Cox regression for probability assessment, results presented with 95% CI.

RESULTS

Of 66 post-traumatic multiple sclerosis cases, 30 (0.10%) had pTBI, and 36 (0.09%) were in the reference group. Cumulative incidence rates (CIR) in the first 10 years were 46.5 per 100,000 (pTBI) and 33.1 per 100,000 (reference). Hazard ratio (HR) for pTBI was 1.10 (95% CI: 0.56-1.48).Stratified by gender, women's CIR was 197.9 per 100,000 (pTBI) and 167.0 per 100,000 (reference) after 15 years. For men, CIR was 44.6 per 100,000 (pTBI) and 34.7 per 100,000 (reference). In the initial 3 years, HR for female pTBI was 1.75 (95% CI: 0.05-6.32), and between years 3 and 20, it was 1.08 (95% CI: 0.51-1.67). For male patients, HR was 1.74 (95% CI: 0.69-4.39).

SIGNIFICANCE

We did not find evidence of an association between pTBI and early-onset multiple sclerosis 20 years post-initial trauma.

Association between pediatric traumatic brain injury and epilepsy at later ages in Finland: A nationwide register-based cohort study

OBJECTIVE

This study was undertaken to examine how pediatric traumatic brain injury (pTBI) correlates with incidence of epilepsy at later ages in Finland.

METHODS

This nationwide retrospective register-based cohort study extended from 1998 to 2018. The study group consisted of 71 969 pediatric (<18 years old) patients hospitalized with TBI and a control group consisting of 64 856 pediatric patients with distal extremity fracture. Epilepsy diagnoses were gathered from the Finnish Social Insurance Institution. Kaplan-Meier and multivariable Cox regression models were conducted to analyze the probability of epilepsy with 95% confidence intervals (CIs).

RESULTS

Cumulative incidence rates (CIRs) for the first 2 years were .5% in the pTBI group and .1% in the control group. The corresponding rates after 15 years of follow-up were 1.5% in the pTBI group and .7% in the control group. Due to proportional hazard violations, the study population was split to the first 2 years and in subgroup analysis 4 years. During the first 2 years of surveillance, the hazard ratio (HR) for the pTBI group was 4.38 (95% CI = 3.39-5.66). However, between years 2 and 20, the HR for the pTBI group was 2.02 (95% CI = 1.71-2.38). A total of 337 patients (.47%) underwent neurosurgery, and 36 (10.7%) patients subsequently developed epilepsy. The CIR for the first year after TBI was 4.5% (95% CI = 2.3-6.7) in operatively managed patients and .3% (95% CI = .3-.4) in nonoperatively managed patients. Corresponding figures after 15 years were 12.0% (95% CI = 8.2-15.8) and 1.5% (95% CI = 1.4-1.6). During the first 4 years of surveillance, the HR for the operative pTBI group was 14.37 (95% CI = 9.29-20.80) and 3.67 (95% CI = 1.63-8.22) between years 4 and 20.

SIGNIFICANCE

pTBI exposes patients to a higher risk for posttraumatic epilepsy for many years after initial trauma. Children who undergo operative management for TBI have a high risk for epilepsy, and this risk was highest during the first 4 years after injury.

Indicators of inflammation after recent tonic-clonic epileptic seizures correlate with plasma interleukin-6 levels

Cerebrospinal fluid (CSF) and peripheral blood pleocytosis have been observed after epileptic seizures without any evidence of infections, but no systematic studies on the acute phase reaction in such patients have been performed. We have previously reported increased levels of interleukin-6 (IL-6) in patients with recent tonic--clonic seizures. Because IL-6 is a major inducer of the systemic acute phase reaction, we decided to study various indicators of inflammation in the blood as well as their correlation with plasma and CSF IL-6 levels. CSF and blood samples were studied from 37 patients with previously undiagnosed and untreated tonic-clonic seizures without any clinical evidence of systemic or central nervous system infections as well as from 40 controls. The mean peripheral blood and CSF-leukocyte counts were significantly higher in patients compared with controls ( 7.9 x 10(9)vs. 6.1 x 10(9), P= 0.002 and 1.9 x 10(6)vs. 1.1 x 10(6), P= 0.032, respectively). There was some indication of increased concentration of C-reactive protein (CRP) and no difference in haptoglobin levels. There was a significant correlation between plasma but not CSF IL-6 concentration and those of both B-leukocyte count ( r= 0.051, P= 0.009) and CRP ( r= 0.42, P= 0.009). Epileptic seizures provoke a production of cytokines such as IL-6 that may in turn cause an activation of the acute phase reaction. Thus, CSF pleocytosis and increase in some indicators of inflammation should not automatically be attributed to systemic or CNS infections in patients with acute seizures.