Predictive role of neurofilament light protein in neurological and mental health outcomes following non-severe trauma among adults: A prospective cohort study at Mulago National Referral Hospital

Abstract

INTRODUCTION- Traumatic Brain Injury (TBI) is a major risk for neurological and neuropsychological disorders. Neuroaxonal damage is a major determinant of outcomes of TBI, and Neurofilament Light chain protein (NfL), a product of this damage, has the potential of enhancing patient stratification, monitoring and prediction of outcomes. METHODS- A total of 176 consenting participants, who met the inclusion criteria, were enrolled in the study and blood obtained to measure serum NfL levels. Data was gathered using a questionnaire and chart abstraction form. Patients were followed for three months post-enrollment to assess neurologic recovery via the Glasgow Outcome Score Extended (GOSE), depression using the Patient Health Questionnaire (PHQ-9), and Post-Traumatic Stress Disorder (PTSD) through a standard checklist. Univariate analysis, bivariate analysis and multivariate analysis were done. RESULTS: Significant predictors of GCS included time to hospital post-trauma, neurological deficits, and distance from Kampala. Patients with elevated NfL levels had a 10% to 20% higher likelihood of presenting with a moderate pre and post resuscitation GCS (P=0.9 and P=0.6) respectively. 134 patients were followed up, 38 (28%) had unfavorable neurological outcomes. Significant predictors for Unfavorable outcomes- arrival time to hospital, motor neurological deficits and surgery. Multivariate analysis, none of the patient’s characteristic predicted unfavourable outcomes. Prevalence of PTSD was 13%, and those with elevated NfL levels were 7% more likely to develop PTSD. Patients with moderate GCS were twice as likely to have PTSD (P=0.05). Multivariate analysis, none of the patient’s characteristics predicted the risk of developing PTSD. Prevalence of depression was 33%, those with high NfL levels were twice as likely to develop depression (p=0.03). Significant variables included- arrival time hospital, moderate pre & post resuscitation GCS, surgery, poor progress at discharge and poor recent memory increased risk for depression. Multivariate analysis, none of the patient’s characteristics significantly predicted the risk of developing depression. CONCLUSIONS- The study found no association in NfL levels among patients with mild and moderate GCS scores at admission, nor in the neurological and mental health outcomes three months post injury. Recommendation- larger studies with diverse populations to clarify NfL's role in neurological and mental outcomes after non-severe TBI.