Voxel-based statistical analysis of brain metabolism in patients with growth hormone deficiency after traumatic brain injury

Abstract

Objective: The aim of this study was to investigate the regional cerebral metabolism related to growth hormone deficiency (GHD) after traumatic brain injury (TBI) using F-18 fluorodeoxyglucose positron emission tomography (F-18 FDG PET) images.

Methods: Twenty-three patients with diffuse axonal injury following TBI were enrolled. They underwent brain F-18 FDG PET study and an insulin tolerance test (ITT). According to the results of ITT, they were divided into two groups: patients with GHD and subjects with TBI but normal Growth Hormone (GH). Voxel-based statistical analysis was performed and the regional cerebral glucose metabolism shown on F-18 FDG PET from 10 patients with GHD was compared with those from 13 patients without GHD. Analysis was performed using SPM2 to identify regions where decreased changes in regional cerebral glucose metabolism were significantly related to GHD.

Results: Compared with subjects with TBI but normal GH, patients with GHD after TBI showed decreased cerebral glucose metabolism in the Left superior frontal gyrus, Right angular gyrus, Right superior temporal gyrus, Left inferior temporal gyrus, Left anterior and middle cingulate gyrus and Right anterior and middle cingulate gyrus. (p_uncorrected < 0.005).

Conclusions: The findings are suggestive of the brain region influenced by GHD. These cortical areas are involved in regulation of intellectual function, executive function and working memory.

Keywords:

• Traumatic brain injury
• growth hormone
• PET
• cognition

Declaration of interest

This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (2011-0014043). The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.