1H-magnetic resonance spectroscopy indicates damage to cerebral white matter in the subacute phase after CO poisoning

ObjectiveThe authors examined whether 1H-magnetic resonance spectroscopy (MRS) can identify damage to the centrum semiovale in the subacute phase after CO exposure.MethodsSubjects comprised 29 adult patients who were treated with hyperbaric oxygenation within a range of 4–95 h (mean 18.7 h) after CO exposure. Subjects were classified into three groups according to clinical behaviours: Group A, patients with transit acute symptoms only; Group P, patients with persistent neurological symptoms; and Group D, patients with ‘delayed neuropsychiatric sequelae’ occurring after a lucid interval. MRS of bilateral centrum semiovale was performed 2 weeks after CO inhalation for all patients and 13 healthy volunteers. The mean ratios of choline-containing compounds/creatine (meanCho/Cr) and N-acetylaspartate/Cr (meanNAA/Cr) for bilateral centrum semiovale were calculated and compared between the three CO groups and controls. Myelin basic protein (MBP) concentration in cerebrospinal fluid was examined at 2 weeks to evaluate the degree of demyelination in patients.ResultsMBP concentration was abnormal for almost all patients in Groups P and D, but was not abnormal for any Group A patients. The meanCho/Cr ratios were significantly higher in Groups P and D than in Group A. No significant difference in meanNAA/Cr ratio was seen between the three pathological groups and controls. A significant correlation was identified between MBP and meanCho/Cr ratio.ConclusionsThese results suggest that the Cho/Cr ratio in the subacute phase after CO intoxication represents early demyelination in the centrum semiovale, and can predict chronic neurological symptoms.