gms | German Medical Science

Objective: Syringomyelia without obvious causes such as Chiari malformation, a tumour or spinal injury is a rare condition. One cause may be an arachnoid adhesion or cyst. According to the literature, a conventional myelogram is the diagnostical tool of choice. We studied the relevance of CSF flow studies in MRI in these patients, especially in the spine.

Methods: In the last five years we treated 125 patients (76 women, 49 men) with a syringomyelia without an obvious cause. The average age was 37 years (median 36 years, range 2 – 69). In each patient we performed a MRI study of the brain and the cervical, thoracic and lumbar spine with cardiac gated phase contrast CSF flow studies of the complete central nervous system and in eight patients a myelogram was carried out as well.

Results: In 33 patients we found a restriction of the pulsatile CSF flow in the CSF flow study. Seven of these patients were operated on for the first time with a resection of the cyst wall and decompression of the subarachnoid space (SAS) by an unilateral approach without a laminectomy, three others were operated on for a second time after a primary operation in an other hospital. Only in two patients did a myelogram show the restriction of the CSF flow which was obvious in the MRI. But in all patients with a myelogram without a CSF restriction, the operation revealed an impressive arachnoid cyst or adhesions. In all operated patients ,CSF flow studies after surgery showed a totally free flow and in six a reduced syringomylia.

Conclusions: A myelogram is not the diagnostic tool of choice in primary syringomyelia. Only CSF flow studies with the MRI are reliable. The reason for this may be the different pulse wave velocity of the CSF compared to the contrast medium in the subarachnoid space.