gms | German Medical Science

Objective: Even if there is no evidence of syringomyelia, the presence of an intradural arachnoid cyst should be suspected as the underlying cause of cerebrospinal fluid (CSF) flow obstruction in patients, who present with inconclusive symptoms and have no obvious spinal canal narrowing or spinal cord changes.

Methods: We studied 31 consecutive patients (16 women, 15 men, mean age: 45 years) who had been diagnosed with intradural arachnoid cysts on the basis of cardiac-gated phase-contrast cine magnetic resonance imaging and partial with cardiac-gated cine balanced fast-field echo sequences.

Results: Although all patients had undergone many MRI investigations and had seen several physicians, the diagnosis of an intradural arachnoid cyst without syringomyelia had never been made.

A thorough analysis of sagittal T2-weighted images revealed irregular spinal cord calibres in half of the patients. When compared to patients with syringomyelia, these patients showed a significant decrease in CSF flow velocity in the central canal (p < 0.05).

8 patients required surgical management for urgent symptoms. In these cases, the arachnoid cysts were opened via hemilaminectomy or interlaminar fenestration and an expansive duraplasty was performed.

Five of the 8 patients reported improvement and 3 patients even had a complete resolution of their symptoms. Postoperative cardiac-gated phase-contrast cine MRI and cardiac-gated cine balanced fast-field echo sequences demonstrated free CSF flow.

Conclusions: Once cardiac-gated phase-contrast cine MRI has confirmed the diagnosis of an intradural arachnoid cyst, a minimal surgical procedure can also benefit some of the patients with atypical symptoms and lead to an improvement in specific cases. The diagnosis of this condition, however, is a challenge and remains the key to successful management.