MRI findings in neuro-Behçet's disease. About 104 moroccan patients and literature review

Behçet's disease (BD) is a recognized as a chronic relapsing heterogeneous multisystem inflammatory disorder and a vasculitis of unknown origin which has a peculiar epidemiology. Neurologic involvement has been reported to be less common than other systemic manifestations, but can cause substantial disability.

Our purpose is to determine the magnetic resonance imaging (MRI) patterns in patients with neuro-Behçet's disease (NBD) who had neural parenchymal involvement and cerebral venous thrombosis (CVT).

We present a retrospective study of 104 patients presenting with BD and neurological involvement, collected over a period of 23 years. We included 86 NBD patients who had parenchymal involvement and 18 NBD patients presenting CVT. In this series, we studied the distribution of lesions and their MRI characteristics, in order to define the MRI patterns of neurological involvement.

Concerning parenchymal central nervous system (CNS) pattern, brain MRI showed hypo-intense lesions on T1-weighted images and hyperintense lesions on T2 and FLAIR-weighted images, involving mostly the brainstem (84.8%), basal ganglia, cerebral white matter (CWM), internal capsule and thalamus. The most common imaging finding was the mesodiencephalic junction (MDJ) in 67 (77.9%) patients, basal ganglia in 59 (68.6%) patients, CWM (53.4%), the capsulo-diencephalic region (39.5%) and pontobulbar region (20.9 %). For the extraparenchymal pattern, the brain MRI results of our series showed that the venous involvement was isolated superior sagittal sinus thrombosis in 8 patients (44.4%), isolated lateral sinus thrombosis in 4 patients (22.2%), and concomitant sagittal sinus thrombosis and right lateral sinus thrombosis in 3 patients (16.6%).

Brain MRI study including contrast and magnetic resonance venography, are mandatory in categorizing the neurological involvement and should be used in cases of suspected NBD. This commonly demonstrates characteristic features especially in acute/sub-acute parenchymal involvement and differentiates NBD from other CNS inflammatory disorders that mimic NBD patterns.