Traumatic brain injury (TBI), a well-known risk factor for pituitary dysfunction, is associated with increased serum neurofilament light chain (NFL), glial fibrillary acidic protein (GFAP), and total tau (t-tau) levels. We aimed to assess the predictive value of these markers and pituitary dysfunction following TBI in a prospective manner.

Adult patients following TBI were included. Serum levels of NFL, GFAP, t-tau and pituitary and target hormones were analyzed prospectively during first week and one year after TBI.

Twenty-two patients (17 males, 5 females; mean age 40±15 years) were included in the study. Basal NFL levels correlated positively with length of hospital stay and basal cortisol (r=0.643, P=0.001 and r=0.558, P=0.007, respectively) and negatively with Glasgow Coma Scale (GCS) score and basal IGF-1 levels (r=−0.429, P=0.046 and r=−0.481, P=0.023, respectively), while there was no significant correlation between GFAP, t-tau and hormone levels. NFL, GFAP, and t-tau levels significantly decreased, and none of the patients developed hormone deficiencies one year after TBI. No correlations were detected between basal markers and first year pituitary hormone levels.

Serum NFL levels were correlated with hormonal changes during acute phase of TBI reflecting the physiological response to trauma. Larger studies are needed to analyze the associations during chronic phase.