Syrinx - MRI

Cervical spine MRI in a 54 year old male patient showing focal dilatation of the central spinal canal with no enhancing focal lesion within the cord. The features are consistent with the focal syrinx.

Discussion:

Hydromyelia: An accumulation of cerebrospinal fluid (CSF) may lead to simple distention of the central canal of the spinal cord lined by ependymal cells.

Syringomyelia: an accumulation of CSF may dissect into the surrounding white matter to form a paracentral cavity, which is not lined by ependyma.

syringohydromyelia: Combination of both which is seen in most of the cases.

I - In 1973, Barnett et al classified syringohydromyelic cavities into 5 types:

1. Communicating (with the subarachnoid space, usually at the level of the obex at the inferior aspect of the fourth ventricle)
2. Posttraumatic
3. Tumor-related
4. Arachnoiditis-related
5. Idiopathic.

II - Milhorat et al, the intramedullary cavities were classified into communicating, noncommunicating, and atrophic types.

III -  Noncommunicating syringes are subdivided into 6 types:

1. Chiari II malformation with hydrocephalus
2. Chiari I malformation without hydrocephalus
3. Extramedullary compressive lesions at the craniocervical junction or along the length of the spinal canal
4. Spinal cord trauma
5. Intramedullary tumors and intraperimedullary infections
6. Multiple sclerosis