Involvement of thyroid hormones in mental recovery following severe craniocerebral trauma

: To study a role of thyroid hormones in the recovery of mental performance, 71 patients (60 males, 11 females) aged 7 to 66 years (mean age 32.7 +/- 3.5) with severe brain injury (TBI). According to the stage of mental recovery (1--none; 2--elementary acts; 3--verbal contact; 4--spatial orientation; 5--intellectual and mnestic processes and emotional and personality traits), the study was divided into 5 series. Immunoradiometric assay of thyroid hormones (T3 and T4) and their free fractions (FT3 and FT4), thyroid-stimulating hormone (TSH), thyroxine-binding globulin (TBG), and prolactin (P) revealed significant alterations in thyroid metabolism at stages 1 to 4, which appeared as low T3 syndrome. The thyrotropin-releasing hormone (TRH) test made in study series 3 to 5 suggests that the patients have neuroendocrine dysfunctions at the mentioned recovery stages of mental functions of the brain. There was a close relationship of clinical parameters (mental time course) to alterations in the thyroid status and metabolism and to morphological impairments of brain tissues in their traumatic damage, which is evidenced by a correlation of the levels of blood and spinal fluid markers (neurone-specific enolase--NSE and protein S-100) of brain injury with psychopathological disorders (r = -0.96 and -0.6, respectively; p < 0.05) and by the assessment of TBI outcomes (r = -0.65 and -0.62, respectively; p < 0.05). Thus, the findings clinically confirm the neurotransmitter role of thyroid hormones at the stages of mental recovery. In addition, the results show that measurement of blood T3, FT3, TSH, T4, TBH, and NSE should be included into neurochemical monitoring in SBI as prognostically significant criteria. They also may serve as a basis for timely correction of thyroid metabolism.