Hormonal Dysfunction in Paediatric Patients Admitted to Rehabilitation for Severe Traumatic Brain Injury: Analysis of the Associations with Rehabilitation Outcomes.

Traumatic brain injury is often accompanied by defects in hormone levels, caused by either peripheral gland dysfunctions or by an insufficient central stimulation of hormone production. The epidemiology of endocrinological defects after traumatic brain injury is quite well described, but the consequences of hormone defects are largely unknown, especially in paediatric patients undergoing neurological rehabilitation. Only one previous study reported on a cohort of 20 children with traumatic brain injury and found a low incidence of hormone defects and a correlation between some hormone levels and neurological recovery. In this study, we performed a retrospective chart review on patients affected by severe subacute traumatic brain injury. Their levels of cortisol, ACTH, IGF-1, TSH, free T4, free T3, and prolactin were collected and compared with reference ranges; we then used regression models to highlight any correlation among them and with clinical variables; last, we probed with regression models whether hormone levels could have any correlation with clinical and rehabilitation outcomes. We found eligible data from the records of 52 paediatric patients with markedly severe traumatic brain injury, as shown by an average GCS of 4.7; their age was 10.3 years, on average. The key results of our study are that 32% patients had low IGF-1 levels and in multiple regression models, IGF-1 levels were correlated with neurological recovery, indicating a possible role as a biomarker. Moreover, 69% of patients had high prolactin levels, possibly due to physical pain and high stress levels. This study is limited by the variable timing of the IGF-1 sampling, between 1 and 2 months after injury. Further studies are required to confirm our exploratory findings.