Behçet Disease: Multisystem Imaging Review

• Etiology & Diagnosis
• Chronic relapsing vasculitis of all vessel sizes
• Dx = recurrent oral ulcers + ≥2 (genital ulcers / uveitis / skin lesions / pathergy +)
• Imaging used for systemic involvement & complications, not primary diagnosis

Neurologic (Neuro-Behçet)

• Two phenotypes: parenchymal vs non-parenchymal (CVST / IH)

Parenchymal (brainstem-dominant)

• ▶ Brainstem > thalamus > white matter
• ▶ T2/FLAIR high signal; +/- enhancement if acute
• ▶ Chronic: atrophy, T1 black holes
• Mimics: MS / ADEM / tumor / abscess

Non-parenchymal

• ▶ CVST → empty delta / loss of flow void / venous infarct
• ▶ Intracranial hypertension → papilledema ± normal MRI
• Vascular Involvement (Vasculo-Behçet)
• Venous >>> Arterial
• Venous: DVT, IVC/SVC thrombosis, Budd–Chiari, portal cavernoma
• Arterial: saccular aneurysms (aorta, pulmonary, femoral) ± rupture risk
• Aneurysm recurrence after surgery is common

Phenotypes

• Parenchymal NBD — inflammatory meningo-encephalitis (brainstem-dominant)
• Non-parenchymal NBD — venous disease (CVST / IH) without parenchymal inflammation
• Mixed — CVST + parenchymal lesions

Parenchymal NBD — Where it lives

• Brainstem → midbrain & pons = MOST classic
• Deep gray → thalamus / basal ganglia
• White matter → periventricular & deep; spinal cord also possible
• Less typical: cortical, tumor-like, solitary “mass-like” lesions

Non-Parenchymal NBD

• Cerebral venous sinus thrombosis (CVST) → most typical
• CT: “empty-delta”
• MRV/SWI: loss of flow void / absent sinus signal
• Intracranial hypertension ± papilledema
• MRI may be normal or show secondary venous changes

Neuro-clinical Correlation

• Parenchymal → pyramidal signs, cranial nerve palsy, ocular involvement, dysarthria
• Non-parenchymal → headache, papilledema, CVST, high ICP
• Mixed → headache + pyramidal ± fever/diplopia

Thoracic

• Pulmonary artery aneurysm or thrombosis
• SVC syndrome → downhill varices
• PE / infarction / pericardial vasculitis

GI Tract

• Deep “punched-out” ileocecal ulcers ± fistula/perforation
• Less often: stomach/esophagus ulcers; post-op recurrence frequent

Cardiac

• Intracardiac thrombus, endomyocardial fibrosis, sinus of Valsalva aneurysm
• Rare but life-threatening

Treatment Pearls

• Steroids + immunosuppressives (esp. neurologic/vascular)
• Avoid early surgery when possible — high recurrence & pseudoaneurysm risk