Value of proton magnetic resonance spectroscopy of brain to study the cerebral metabolic abnormalities in COPD: Initial experience

ABSTRACT

Chronic obstructive pulmonary disease [COPD] patients were found to have cerebral metabolic abnormalities. Proton magnetic resonance spectroscopy [1H MRS] is a sensitive technique that detects metabolic changes of the brain. To study the cerebral metabolic changes in COPD patients using 1H MRS. This study was carried-out on twenty symptomatic COPD patients [16 male and 4 female] and age matched group of 20 healthy controls [11 male and 19 female]. Pulmonary function tests, respiratory muscle strength, resting arterial blood gases, and 1H MRS of the brain were carried out on all subjects. The parieto-temporal and occipital regions were localized for 1H MRS. The metabolic ratios of 7V-acetyl aspartate to creatine [NAA/Cr] and choline to creatine [Cho/Cr] were calculated by the single voxel technique. In comparison with healthy control subjects, the mean values of Cho/Cr in COPD patients were lower in parietotemporal and occipital areas [0.99 +/- 0.21 vs. 1.10 +/- 0.31; P = 0.22] [0.81 +/- 0.26 vs. 0.88 +/- 0.21; P = 0.37], respectively while, the mean values of NAA/ Cr in COPD patients were higher in both parieto-temporal and occipital areas of the brain [1.82 +/- 0.35 vs. 1.68 +/- 0.22; P = 0.14] [1.59 +/- 0.31 vs. 1.39 +/- 0.39; P = 0.08], respectively. In COPD patients, significant positive correlations were observed between maximal expiratory pressure [MEP] and NAA/Cr in parieto-temporal area of the brain. The cerebral metabolites, arterial blood gases, respiratory muscle strength, and pulmonary function tests are altered in symptomatic COPD patients. 1H MRS is a non invasive technique that detects cerebral metabolic changes in COPD patients