MRI Findings in Multiple Spinal Arachnoid Cysts: A Rare Cause of Acute Paraplegia

Background: Spinal arachnoid cysts (SACs) are rare benign lesions arising from the arachnoid membrane containing cerebrospinal fluid (CSF). They are usually solitary and asymptomatic and are often discovered incidentally. Symptomatic patient may develop progressive neurological deficits due to spinal cord or nerve root compression. The presence of multiple intradural arachnoid cysts is an exceptional finding, and with very few have been reported in the literature. These lesions pose diagnostic and therapeutic challenges, particularly when they extend over several vertebral levels. MRI is the gold standard for their identification, as it allows precise assessment of their number, size, location, and impact on adjacent neural structures. Case Presentation: A 34-year-old woman with no relevant medical history developed sudden-onset paraplegia associated with urinary retention and sensory disturbances. Clinical examination confirmed thoracic sensory level and flaccid paraplegia. MRI of the spinal cord demonstrated multiple intradural extramedullary arachnoid cysts spanning several thoracic levels, causing significant spinal cordcompression, with no associated hemorrhage or neoplastic lesion. There was no evidence of prior trauma, surgery, or infection. Conclusion: Multiple intradural spinal arachnoid cysts are an uncommon but important differential diagnosis in patients with acute myelopathy. MRI plays a central role in their diagnosis, enabling not only detection but also differentiation from other cystic or neoplastic lesions. Recognizing this rare entity is essential for timely management and preventing unnecessary or inappropriate interventions.