Cobb syndrome

Cobb syndrome, also called cutaneous vertebral medullary angiomatosis, or spinal arteriovenous metameric syndrome, consists of the presence of a vascular nevus with a spinal vascular malformation of the same body somite (metamere). 

The importance of this syndrome is the recognition that cutaneous vascular lesions may hint at an accompanying spinal cord angioma/AVM that may result in weakness or paralysis.

Clinical presentation

Patients typically present in childhood or adolescence with sudden onset of back or lower extremity radicular pain associated with numbness that can be localized below a specific dermatome.

Pathology

Cobb syndrome results from a metameric vascular malformation that involves all three layers (ectoderm, mesoderm and neural tissue) of the same segmental dermatome.

Radiographic features

Plain radiograph

The classic finding on plain film is vertical striations of the vertebral body. Plain films are usually of limited value but on occasion may show bony erosion of the spinal canal involving pedicles, lamina, or foramina in addition to involvement of the vertebral body.

CT

CT imaging may demonstrate intramedullary or epidural hemorrhage. Plain CT with bone windows may demonstrate vertebral body erosion and assist in determining whether the lesion originates from the spinal canal or from the vertebral body. Foraminal enlargement may also suggest the presence of dilated venous structures compressing exiting nerve roots in patients with symptoms of radiculopathy.

Treatment and prognosis

Patients should be referred to a neurosurgeon and an interventional radiologist for embolization and decompression.

Complications

A possible complication if treatment is delayed is Foix-Alajouanine disease or subacute necrotic myelopathy due to thrombosis in the spinal angioma.

History and etymology

The renowned American neurologist Stanley Cobb (1888-1968) provided a full description of this condition in 1915, but Berenbruch described a case in 1890 ⁴.