Behçet disease (CNS manifestations)

CNS manifestations of Behçetdisease, also also known as neuro-Behçet disease, corresponds corresponds to the neurological involvement of the systemic vasculitis Behçet disease and has a variety of manifestations.

For a discussion of the disease, in general, please refer to Behçet disease article.

Epidemiology

CNS involvement is seen in 4-49% of patients with systemic Behçet disease and has the same predilection of patients of middle eastern and Japanese descent ¹.

Clinical presentation

In the vast majority of cases, ulcerative lesions preceded neurological involvement, aiding in the diagnosis. In 3% of cases, central nervous system manifestations occur first, making diagnosis significantly more challenging ¹. Signs and symptoms include ¹:

• headaches

• sensory disturbances

• personality changes

• dysarthria

• cerebellar signs

Pathology

Neuro-Behçet disease, depending depending on the stage or degree of the inflammation, shows shows perivascular infiltration of leucocytes and microglia, degeneration of oligodendroglia, and perivascular softening or necrosis ³.

Radiographic features

Neuro-Behçet disease has a wide variety of manifestations in the central nervous system, including ¹:

• focal or multifocal lesions

• meningoencephalitis

• cerebral vein thrombosis

Meningoencephalitis and cerebral veinvenous thrombosis are discussed separately in general articles related to these conditions.

MRI

Lesions in neuro-Behçet disease typically involve ^1,3,5, in order of preference:

• brainstem: most common, and typically in the pons

• basal ganglia: bilateral in one-third of cases

• thalamus

• subcortical white matter: less common

• spinal cord: less common, often as longitudinally extensive transverse myelitis with the bagel sign

Lesions in neuro-Behçet disease typically demonstrate the following signal characteristics ¹:

• T1: usually hypointense

• T2:

  • usually hyperintense

  • associated with vasogenic oedema

  • in acute phase, lesions cause mass effect

• T1 C+ (Gd): typically moderate patchy enhancement

• DWI: isointense to slightly hyperintense

• MRS: drop drop in NAA, with elevated lipid and choline/creatine ratio ⁴

Treatment and prognosis

• corticosteroids: intravenous intravenous methylprednisolone infusion then oral prednisone

• steroid-sparing immunosuppression: azathioprine, methotrexate, and TNFα inhibitors ²

Differential diagnosis

General imaging differential considerations include

• multiple sclerosis

• neurosarcoidosis

• primary CNS lymphoma

• gliomatosis cerebri

• antiphospholipid syndrome

• Sweet syndrome

Consider other causes of T2 hyperintensity of the basal ganglia.