Neurological Symptoms of Neuro-Behçet's Disease
Neuro-Behçet's disease presents with two distinct patterns: parenchymal CNS involvement (most common, ~80%) causing brainstem syndromes, headache, focal deficits, and movement disorders; and non-parenchymal involvement causing cerebral venous sinus thrombosis with intracranial hypertension. 1
Clinical Presentation Patterns
Parenchymal Type (Most Common)
Brainstem syndrome is the hallmark presentation, occurring in approximately 50% of cases 2:
- Mesodiencephalic lesions extending from thalamus to midbrain (creates characteristic "cascade sign" on MRI)
- Ophthalmoplegia (50% of cases)
- Cerebellar ataxia and gait abnormalities (66-67%)
- Diplopia (66.7%)
- Dysarthria and bulbar symptoms
Common symptoms across all parenchymal presentations 1, 3, 2:
- Headache (83-87% of cases) - most frequent initial symptom
- Paresthesias, tingling, and numbness (83%)
- Weakness and hemiplegia (50%)
- Unsteadiness (66.7%)
Neurological signs on examination 3, 2:
- Hyperreflexia and upward plantar reflexes
- Sensory abnormalities (66.7%)
- Focal motor deficits (33%)
- Pyramidal tract signs
Non-Parenchymal Type
Cerebral venous sinus thrombosis (CVST) 4, 1:
- Presents with intracranial hypertension syndrome rather than focal deficits
- Severe headache with papilledema
- Can involve superior sagittal sinus, transverse sinuses, or deep venous system
- Distinguished from parenchymal disease by predominance of raised intracranial pressure symptoms
Additional Neurological Syndromes
The disease can mimic multiple other conditions 1, 3, 2:
- Multiple sclerosis-like presentation with relapsing-remitting course
- Meningoencephalitic syndrome with fever and meningismus (27-33% of cases) 5, 6
- Myelopathic syndrome with noncontiguous multifocal cervical/thoracic cord lesions
- Stroke-like syndromes in young adults (hemispheral or brainstem distribution)
- Movement disorders
- Psychiatric disturbances (less common)
- Peripheral neuropathy (rare, ~2.5% of cases)
Temporal Patterns
Subacute onset with relapsing-remitting course is most typical 2:
- Symptoms develop over days to weeks
- 40% have unfavorable neurological outcomes without treatment 6
- Relapses are common, especially if immunosuppression is discontinued 7
Diagnostic Clues
CSF findings differ by type 1:
- Parenchymal NBD: Lymphocytic pleocytosis, elevated protein (100% abnormal in acute phase), normal glucose
- CVST: Elevated opening pressure but often normal cell count and chemistry
MRI characteristics 1:
- Acute: Mesodiencephalic T2 hyperintensities with "cascade sign"
- Chronic: Brain/brainstem atrophy, "black holes"
- Spinal: Noncontiguous multifocal lesions (cervical > thoracic)
Critical Pitfalls
Do not miss CVST - it requires different management than parenchymal disease. CVST presents with intracranial hypertension rather than focal deficits and needs immunosuppression ± anticoagulation 8.
Avoid ciclosporine A in patients with CNS involvement unless absolutely necessary for severe uveitis - it can worsen neurological disease 8.
Consider NBD in young patients with stroke - it's a masquerader that must be in the differential for stroke in patients under 40, especially with recurrent episodes 3, 7.
Recognize that neurological involvement carries poor prognosis - approximately 2.6-6.3% of Behçet's patients develop NBD, but it causes severe disability and requires aggressive treatment 9, 3.