title: Proton magnetic resonance spectroscopy of periventricular white matter and hippocampus in obstructive sleep apnea patients.
abstract: BACKGROUND
  The purpose of this study was to diagnose the hypoxic impairment by Magnetic resonance spectroscopy (MRS), an advanced MR imaging technique, which could not be visualised by routine imaging methods in patients with obstructive sleep apnea (OSA).
  
  
  METHODS
  20 OSA patients and 5 controls were included in this prospective research. MRS was performed on these 25 subjects to examine cerebral hypoxemia in specific regions (periventricular white matter and both hippocampi). Polysomnography was assumed as the gold standard. Statistical analysis was assessed by Mann-Whitney U test and Receiver operating characteristics (ROC) curve for NAA/Cho, NAA/Cr and Cho/Cr ratios.
  
  
  RESULTS
  In the periventricular white matter, NAA/Cho ratio in OSA patients was significantly lower than in the control group (p<0.05). There were no statistical differences between the OSA and the control group for NAA/Cho, NAA/Cr and Cho/Cr ratios for both hippocampal regions. Additionally, Cho/Cr ratio in the periventricular white matter region of OSA group was higher than in the control group (p<0.05).
  
  
  CONCLUSIONS
  Hypoxic impairment induced by repeated episodes of apnea leads to significant neuronal damage in OSA patients. MRS provides valuable information in the assessment of hypoxic ischemic impairment by revealing important metabolite ratios for the specific areas of the brain.
authors: Department of Radiology, Afyonkarahisar State Hospital, Afyonkarahisar, Turkey.
authors: Volkan
authors: V
authors: Kızılgöz
authors: Department of Radiology, Dışkapı Yıldırım Beyazıt Education and Research Hospital, Ankara, Turkey.
authors: Hasan
authors: H
authors: Aydın
authors: Department of Radiology, Dışkapı Yıldırım Beyazıt Education and Research Hospital, Ankara, Turkey.
authors: Idil Güneş
authors: IG
authors: Tatar
authors: Department of Radiology, Dışkapı Yıldırım Beyazıt Education and Research Hospital, Ankara, Turkey.
authors: Baki
authors: B
authors: Hekimoğlu
authors: Department of Chest Diseases, Dışkapı Yıldırım Beyazıt Education and Research Hospital, Ankara, Turkey.
authors: Sadık
authors: S
authors: Ardıç
authors: Department of Chest Diseases, Dışkapı Yıldırım Beyazıt Education and Research Hospital, Ankara, Turkey.
authors: Hikmet
authors: H
authors: Fırat
authors: Department of Neurology, Dışkapı Yıldırım Beyazıt Education and Research Hospital, Ankara, Turkey.
authors: Cem
authors: C
authors: Dönmez
keywords: magnetic resonance; magnetic resonance spectroscopy; polysomnography; sleep apnea syndromes; sleep disorders