Cobb syndrome

The Cobb syndrome also called cutaneous vertebral medullary angiomatosis is a metameric vascular malformation that involves all three layers (ectoderm, mesoderm and neural tissue) of the same segmental dermatome.

The importance of this syndrome is the recognition that cutaneous vascular lesions may hint at an accompanying spinal cord angioma or 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.

Radiographic features

Plain film

The classic finding on plain film was 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 itself

CT

CT imaging may demonstrate intra-medullary or epidural haemorrhage. 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.

Complications

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

Treatment and prognosis

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