Neuro-Ocular-Vasculo-Behcet: MR imaging findings.

Clinical History

A 50-year-old male presented with Behcet syndrome and a ten year history of bilateral iridocyclitis and posterior uveitis. Ocular symptoms included periorbital pain, redness, photophobia, and blurred vision. The patient came for optic pathway and brain magnetic resonance imaging (MRI) with atypical symptoms such as headaches and recently, personality changes.

Imaging Findings

MRI of the orbits revealed bilateral optic nerve and optic chiasm atrophy on STIR images (Fig.1, 2). The periventricular and the subcortical white matter showed multiple confluent lesions with high signal intensity on T2- weighted and FLAIR images (Fig.3, 4).

Discussion

Behcet disease is a multi-systemic and chronic inflammatory vasculitis of unknown aetiology. The mean age at which Behcet disease occurs is 30-40 years and is most prevalent in the Mediterranean, Middle East and East Asia. The highest incidence has been reported in Turkey and males are affected 2-5 times more often than females [1-4]. The disease is characterized by recurrent oral and genital ulcers, uveitis, chronic, relapsing obstructive vasculitis affecting vessels of differing sizes in various organs and other clinical manifestations in multiple organ systems [1-3].
The central nervous system (CNS) involvement occurs in about 10% to 50% of patients and develops more than 10 years after the onset of Behcet disease. Signs and symptoms include headaches, sensory disturbances, personality changes, dysarthria and cerebellar signs [1-3].
The CNS manifestations of Behcet disease classified as parenchymal or non-parenchymal [1-2]. The parenchymal lesions represent lymphocytic and monocytic cellular infiltration of veins, capillaries and arteries of all sizes, causing in acute phase demyelination and oedema. As lesions become more chronic, excessive gliosis and atrophy are seen [1-3]. MRI findings include small foci of high signal intensity on T2-weighted and FLAIR images in the periventricular and subcortical white matter. The thalamus, the basal ganglia and the brainstem are the next most common sites of involvement. Similar foci can be noted in the cerebral hemispheres while the spinal cord rarely can be affected. Differential diagnosis includes multiple sclerosis (periventricular lesions, Dawson's figers, U-fibers involvement , "black holes") and neuromyelitis optica (optic neuritis, normal or atypical for MS brain MRI, transverse myelitis with spinal cord lesions longer than 3 spinal segments). Sometimes neuro-Behcet disease may manifest as a tumour-like lesion and make the diagnosis even more difficult if there are no typical clinical symptoms. Steroid administration may be a diagnostic and therapeutic option in uncertain clinical situations [1-4]. The CNS non-parenchymal involvement includes intracranial hypertension, aseptic meningitis, cranial neuropathy, and cerebrovascular disorders such as dural sinus thrombosis, aneurysms and less common arterial dissection and occlusion [3-5]. The frequency of ocular involvement in patients with Behcet disease ranges between 70% and 95% in most of the series. Iridocyclitis may be isolated finding but is often observed with posterior- or panuveitis. At the end stage of the ocular disease, the repeated episodes of posterior segment inflammation cause total optic disk atrophy leading to Wallerian degeneration of the optic nerves, chiasm and optic radiation [6, 7].

Differential Diagnosis List

Final Diagnosis

Neuro-Ocular-Behcet disease.

URL:	https://www.eurorad.org/case/14258
DOI:	10.1594/EURORAD/CASE.14258
ISSN:	1563-4086