Syringomyelia: how MRI aids diagnosis and management.

MRI is an invaluable tool in the diagnosis and assessment of treatment of syringomyelia. It also confirms the theory of the pathogenesis of the disease and suggests why some operations on the condition fail. A series of patients with Chiari I, with and without syringomyelia, have been studied with MRI both prior to surgery and following treatment. In four cases, with Chiari I alone and minor symptoms only, management has been conservative. No progression of symptoms or signs have been seen, MRI allowing syringomyelia to be excluded, both at diagnosis or development during follow-up. Patients with Chiari I, six with and one without syringomyelia, were split into two groups; those with symptoms and signs of cervico medullary compression (CMC) and those with pure cord amyotrophy with upper limb weakness and numbness of typical "cape type". In three CMC patients, foramen magnum decompression (FMD) with fascia lata grafting and high syringotomy, and in two FMD without syringotomy, were carried out. The procedure improved pain, CMC symptomatology and clinical signs, but had only minor effects on amyotrophic symptoms. Some improvement was seen after surgery in distention of the syrinx on MRI studies, but there was no progression in the syrinx cavities. In two patients with pure amyotrophic the syrinx cavities. In two patients with pure amyotrophic symptoms, primary syringoperitoneal shunting (SPS) was carried out, and a further two patients with primary FMD subsequently went on to SPS for amyotrophic symptoms and signs.(ABSTRACT TRUNCATED AT 250 WORDS)