title: Investigation of brain GABA+ in primary hypothyroidism using edited proton MR spectroscopy.
abstract: OBJECTIVE
  Evidence indicates that thyroid hormones have effects on the inhibitory GABAergic system. The aim of this study was to investigate whether brain GABA levels are altered in patients with hypothyroidism compared with healthy controls.
  
  
  METHODS
  Fifteen patients with primary hypothyroidism and 15 matched healthy controls underwent single-voxel MEGA-PRESS magnetic resonance spectroscopy at 3T, to quantify GABA levels in the median prefrontal cortex (mPFC) and posterior cingulate cortex (PCC). All participants underwent thyroid function test. Neuropsychological performances were evaluated by administration of the Montreal Cognitive Assessment (MoCA) and the 21-item Beck Depression Inventory-II (BDI-II).
  
  
  RESULTS
  The patients with hypothyroidism had significantly lower GABA+ levels in the mPFC compared with healthy controls (P = 0·016), whereas no significant difference (P = 0·214) was observed in the PCC. Exploratory analyses revealed that mPFC GABA+ levels were negatively correlated with the BDI-II scores in patient group (r = -0·60, P = 0·018). No correlations were found between GABA+ levels and TSH or fT3 or fT4 levels in either region (all P > 0·05).
  
  
  CONCLUSIONS
  This study suggests that alteration of GABAergic neurotransmission may play an important role in the pathophysiology of primary hypothyroidism, providing intriguing neurochemical clues to understand thyroid-brain interactions.
authors: Department of Radiology, Qilu Hospital of Shandong University, Jinan, China.
authors: Bo
authors: B
authors: Liu
authors: Shandong Medical Imaging Research Institute affiliated to Shandong University, Jinan, China.
authors: Huan
authors: H
authors: Yang
authors: Shandong Medical Imaging Research Institute affiliated to Shandong University, Jinan, China.
authors: Fei
authors: F
authors: Gao
authors: Department of Radiology, Qilu Hospital of Shandong University, Jinan, China.
authors: Qing
authors: Q
authors: Wang
authors: Shandong Medical Imaging Research Institute affiliated to Shandong University, Jinan, China.
authors: Bin
authors: B
authors: Zhao
authors: Shandong Medical Imaging Research Institute affiliated to Shandong University, Jinan, China.
authors: Tao
authors: T
authors: Gong
authors: Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China.
authors: Zhensong
authors: Z
authors: Wang
authors: Philips Healthcare, Shanghai, China.
authors: Weibo
authors: W
authors: Chen
authors: Shandong Medical Imaging Research Institute affiliated to Shandong University, Jinan, China.
authors: Guangbin
authors: G
authors: Wang
authors: Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Richard A E
authors: RA
authors: Edden
mesh_terms: D000328:Adult; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D016022:Case-Control Studies; D005260:Female; D006179:Gyrus Cinguli / Q000737:chemistry; D006801:Humans; D007037:Hypothyroidism / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000737:chemistry; D066244:Proton Magnetic Resonance Spectroscopy; D013960:Thyroid Function Tests; D013963:Thyroid Hormones; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000032:analysis*
chemical_list: D013963:Thyroid Hormones; D005680:gamma-Aminobutyric Acid