Cerebral metabolic disturbance as detected with magnetic resonance spectroscopy in neuropsychiatric systemic lupus erythematosus

ABSTRACT

To evaluate the spectral brain changes using 1H-MR spectroscopy in Neuropsychiatric Systemic Lupus Erythematosus [NPSLE] patients and, to correlate their neuropsychiatric clinical data with MRI and 1 PI-MRS abnormalities. Twenty three NPSLE patients and 8 age and sex matched control volunteers were included. Disease activity was measured by SLE Disease Activity Index [SEEDAI]. Patients were classified into two groups; the first included NPSEE patients with normal MRI, and the second included those with abnormal MRI. Single voxel proton MRS was evaluated in the parieto-occipital white matter in all patients and volunteers and in areas of MRI abnormal lesions. The metabolic peaks were fitted at known frequencies where N-acetylaspartate [NAA] at 2.02 ppm, creatine [Cr] at 3.02 ppm, and choline [Cho] at 3.22 ppm. The relative ratios of NAA to Cr and of Cho to Cr we measured. the most common neuropsychiatric features were headache and cognitive impairment with 39.1% for each of them, 9 patients had abnormal MRI imaging, while spectral changes were present in 20 patients. MRS changes were in agreement and statistically significant [P=0.001] with the neuropsychiatric manifestations, compared with MRI changes [P=0.8]. Neuropsychological tests were significantly affected in patients with abnormal MRI versus those with normal ones. In patients with abnormal MRI, the NAA/Cr ratio was significantly lower than those with normal MRL while the Cho/Cr ratio was significantly higher. In patients with NPSLE, 1H-MR spectroscopic findings seem to reflect the cerebral metabolic disturbances as functional abnormalities, related to the neuropsychiatric symptoms. It is a complementary tool to MRI in diagnosing the CNS involvement