Increased Detectability of Alpha Brain Glutamate/Glutamine in Neonatal Hypoxic-Ischemic Encephalopathy

• Published in: American journal of neuroradiology : AJNR 2000-01, Vol.21 (1), p.203-212
• Main Authors: Pu, Yonglin, Li, Qing-Feng, Zeng, Chao-Mei, Gao, Jian, Qi, Jing, Luo, De-Xin, Mahankali, Srikanth, Fox, Peter T, Gao, Jia-Hong
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Brain - metabolism; Brain Ischemia - metabolism; Delivery. Postpartum. Lactation; Disorders; Follow-Up Studies; Glutamic Acid - metabolism; Glutamine - metabolism; Gynecology. Andrology. Obstetrics; Humans; Hypoxia, Brain - metabolism; Infant, Newborn; Magnetic Resonance Spectroscopy; Medical sciences; Pediatrics; Tropical medicine
• ISSN: 0195-6108; 1936-959X

Proton MR spectroscopy (MRS) detectability of brain glutamate/glutamine (Glx) is increased in hypoxic-ischemic insults and is implicated in the neuronal injury and death that follows. Our aim was to correlate the proton MRS detectability of alpha-CH protons of Glx (alpha-Glx) with the Sarnat stage of neonatal hypoxic-ischemic encephalopathy (HIE). Initial and follow-up proton MRS studies at 1.9 T were performed in 28 neonates aged 1 to 7 days (seven healthy control subjects and 21 with HIE: 10 mild, nine moderate, and two severe) and in 12 neonates aged 13 to 17 days (12 with HIE: eight mild, three moderate, and one severe), respectively. Both point-resolved spectroscopy (PRESS) and stimulated-echo acquisition mode (STEAM) sequences were used. The spectral volume of interest was in the basal ganglia, thalami, and adjoining regions. The detectability of alpha-Glx was assessed by two different parameters: the detection rate of the alpha-Glx peak and the peak-area ratio of alpha-Glx to creatine and phosphocreatine. On both the initial and follow-up PRESS studies, all the neonates with moderate and severe HIE showed an alpha-Glx peak, compared with one healthy control subject in the initial study and one neonate with mild HIE in both the studies. They also demonstrated a significantly higher peak-area ratio of alpha-Glx/(creatine and phosphocreatine) on both the initial and follow-up studies. The peak-area ratios in neonates with HIE positively correlated with the Sarnat stage of HIE on both the initial and follow-up studies. Neonates with moderate and severe HIE also showed a consistently higher alpha-Glx peak on both the initial and follow-up studies with the STEAM sequence. Proton MRS detectability of alpha-Glx is increased in moderate and severe HIE and correlates with the Sarnat stage of HIE.