Background: Diagnostic evaluation of patients with parenchymal Neuro-Behçet's disease (NBD) requires magnetic resonance imaging (MRI), neuro-ophthalmologic, and neuropsychological evaluation. In this study, we aimed to find out the ideal diagnostic method that most closely reflects the progress in cognitive disability and brain atrophy in NBD.
Methods: In this matched case-control study, we included patients with parenchymal NBD, Behçet's disease without neurological involvement (BD), rheumatoid arthritis, and healthy controls. Detailed ophthalmological examination, pattern-reversal visual evoked potentials (prVEP) test, optical coherence tomography (OCT), brain MRI volumetry and cognitive evaluation tests were performed. Disability status was assessed by revised EDSS.
Results: Sixty-eight individuals (35 female, 33 male) were recruited. Mean ACE-R scores were significantly lower in the NBD group (NBD vs. healthy, 80±14.4, 93±4.9, p=0.002). prVEP values were similar across groups, but retinal nerve fiber layer thickness (RNFLT) were more frequently abnormal in the NBD group. We found considerable volume reduction in the brainstem, cerebellum, hippocampus, and thalamus in the NBD group. Regarding prVEP, 120 minutes P100 amplitude (p<0.001, r=0.97) and 60 minutes P100 amplitude values (p=0.006, r=0.90) were positively correlated with the total cerebral white matter volume.
Conclusion: Our results confirmed previous observations on cognitive dysfunction in patients with NBD. We reported MRI volumetry data of patients with parenchymal neuro-Behçet's disease for the first time and elucidated novel brain regions with atrophy. Clinically determined scores and OCT failed to predict the status of brain atrophy. prVEP P100 amplitude may be used as a surrogate marker of cerebral white matter involvement in NBD.