Prevalence of Neurological Involvement in Behçet's Disease

Approximately 5-10% of patients with Behçet's disease develop neurological involvement (neuro-Behçet's disease). 1, 2, 3

Types of Neurological Involvement

Neurological manifestations in Behçet's disease can be classified into two major forms:

Parenchymal involvement: This is the most common form, occurring in the majority of patients with neuro-Behçet's disease. It presents as a vascular-inflammatory central nervous system disease with focal or multifocal parenchymal involvement, predominantly affecting the brainstem-diencephalic regions 1, 2
Extra-parenchymal involvement: This form occurs in 10-20% of neuro-Behçet's cases and primarily manifests as cerebral venous sinus thrombosis (CVST) and intracranial hypertension. It generally has a better neurological prognosis than parenchymal involvement 1, 2

Parenchymal neuro-Behçet's typically presents with:
- Brainstem syndromes 1
- Hemiparesis 1
- Pyramidal signs 4
- Headache 4
MRI findings in parenchymal involvement typically show:
- Inflammatory lesions at the meso-diencephalic junction and brainstem 4
- Ill-defined areas of edema with high signal intensity on T2-FLAIR images 3
- Lesions in the basal ganglia area or brainstem, which may extend to diencephalic structures 3
Extra-parenchymal involvement typically presents with:
- Signs and symptoms of intracranial hypertension 1
- Headache 1
- Visual disturbances 1

Neuro-Behçet's should be considered in the setting of neurological manifestations in a young patient diagnosed with Behçet's disease 4
Diagnosis can be challenging when neurological manifestations are the presenting features of Behçet's disease, which occurs in approximately one-third of cases 4
MRI with contrast is the imaging modality of choice for diagnosing neuro-Behçet's disease 5
Large ovoid lesions close to the floor of the fourth ventricle are characteristic of neuro-Behçet's disease 6

For parenchymal involvement:
- Acute attacks: High-dose intravenous methylprednisolone (1g/day for 5-10 days), followed by oral taper or intermittent pulses 2
- Long-term maintenance: Immunosuppressive agents, with azathioprine being the most widely used 2
- TNF-alpha antagonists are recommended for parenchymal involvement 7
- Severe cases may require cyclophosphamide 8
For cerebral venous sinus thrombosis:
- Corticosteroids are recommended 7
- The use of anticoagulation is controversial due to the risk of bleeding, especially in patients with pulmonary or other aneurysms 2
Cyclosporine A should be avoided in patients with central nervous system involvement due to potential neurotoxicity 7, 9

Venous sinus thrombosis in Behçet's disease has a significantly better neurological prognosis than parenchymal CNS involvement 2
Poor prognostic factors include multifocal involvement, spinal presentations, more than two attacks per year, progressive course, and increased cerebrospinal fluid cell count and protein content 8
Early recognition and treatment are essential to limit the risk of sequelae, relapses, or death 4, 3