Magnetic resonance imaging and proton magnetic resonance spectroscopy in neuro-Behçet's disease.

OBJECTIVE Neuro-Behcet's disease (NBD) is one of the most serious complications of Behcet's disease (BD). Proton magnetic resonance spectroscopy (1H MRS) has been proved to be useful in detecting neuro-metabolic abnormalities in various diseases affecting the brain. In this study, we attempted to characterize the magnetic resonance imaging (MRI) findings in Korean patients with NBD and then examined the usefulness of 1HMRS in evaluating the MRI-negative brain area of NBD patients. METHODS We performed brain MRI in 18 BD patients with neurologic symptoms and signs. Seven NBD patients without thalamic lesions and 8 healthy controls underwent brain 1H MRS, in which an 8 ml voxel was placed in the left thalamus and the N-acetylaspartate (NAA)/creatine (Cr) ratio was measured. RESULTS Fourteen of 18 BD patients were diagnosed as having NBD and 12 NBD patients (86%) had brain lesions on MRI. Most lesions were of high signal intensity on T2-weighted images and located in the midbrain, pons, basal ganglia, and white matter. On 1H MRS, the thalamic area without gross abnormalities on MRI showed a significantly lower NAA/Cr ratio in NBD patients compared to healthy controls (1.07 +/- 0.08 versus 1.54 +/- 0.27, P < 0.01). In 2 NBD patients, the NAA/Cr ratios, monitored serially, were normalized along with clinical improvement 6 months after treatment with prednisolone and immune suppressive agents. CONCLUSION MRI is a very sensitive diagnostic method for NBD, and 1H MRS may be useful for the early detection and follow-up of MRI-negative NBD.