Neuronal loss or dysfunction in patients with early Lyme neuroborreliosis: a proton magnetic resonance spectroscopy study of the brain.

BACKGROUND

We hypothesized that since Borrelia burgdorferi causes systemic inflammation and infects the brain, it may lead to alterations in cerebral metabolism, as measured by 1H-magnetic resonance spectroscopy (1H-MRS). The purpose of our study was to determine whether 1H-MRS could detect brain metabolite alterations in patients with early Lyme neuroborreliosis (LNB) in normal-appearing brain tissue on the conventional magnetic resonance imaging (MRI).

METHODS

Twenty-six patients diagnosed with early LNB and twenty-six healthy volunteers as a control group have been involved in the study. All of them underwent routine MRI protocol using 3.0-T MRI scanner. 1H-MRS examinations were performed with repetition time (TR) = 2000 ms, and echo time (TE) = 135 ms. Single voxels were positioned in the anterior and posterior parts of the right and left frontal lobes.

RESULTS

We found a statistically significant decrease of the N-acetylaspartate/creatine ratio within the anterior part of the right and left frontal lobes (p ≤ 0.001 and p = 0.001 respectively) and in the posterior part of the right and left frontal lobes (p ≤ 0.001 and 0.031) in the patients with LNB.

CONCLUSION

A significant reduction in NAA/Cr ratio in comparison with the controls suggests the presence of diffuse neuronal loss in patients with early LNB.