What is syringomyelia?

Syringomyelia is a condition in which a fluid-filled cavity (syrinx) forms within the spinal cord, causing various symptoms. The reason for the formation of this cavity is still unknown, but what is certain is that it is related to a blockage in the flow of cerebrospinal fluid, and it can be treated by removing this blockage to allow the cerebrospinal fluid to flow normally again.


Syringomyelia can be broadly divided into four types: (1) syringomyelia associated with Chiari malformation; (2) syringomyelia associated with adhesive arachnoiditis; (3) syringomyelia associated with spinal cord tumor; and (4) syringomyelia after spinal hemorrhage. Of these, types 1 and 2 are syringomyelia in the original meaning of the word, and they are explained below.

(a) Syringomyelia associated with Chiari malformation

A Chiari malformation occurs when the lower edge of the cerebellum drops down and pushes into the spinal canal. Chiari is the name of the person who first identified this condition. The reason for the formation of a cavity in the spinal cord when this malformation is present is a great mystery, and numerous theories have been proposed; we ourselves have recently published a paper proposing a new hypothesis about this issue. All that can be said is that its formation is related to a blockage in the flow of the watery fluid that flows around the spinal cord, called cerebrospinal fluid.

(b) Syringomyelia associated with adhesive subarachnoiditis

Adhesive subarachnoiditis is a condition in which the space through which the fluid flows around the spinal cord becomes inflamed for some reason. In this type of syringomyelia, this inflammation interferes with the flow of cerebrospinal fluid, causing a cavity to develop below that point. It was formerly believed to be comparatively rare, but since the advent of widespread MRI scanning, it is being diagnosed more often.

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