Septum posticum cysts: an uncommon cause of chronic back pain

Neuroimaging findings and pathophysiology of dorsal spinal arachnoid webs: illustrative case

BACKGROUND

Spinal arachnoid webs are uncommon and difficult to diagnose, especially because causative intradural transverse bands of arachnoid tissue are radiographically occult. Left untreated, arachnoid webs may cause progressive, debilitating, and permanent neurological dysfunction. Conversely, more than 90% of patients may experience rapid neurological recovery after resection, even with a prolonged duration of presenting symptoms. Indirect imaging signs such as spinal cord indentation and compression with cerebrospinal fluid (CSF) flow alteration provide crucial diagnostic clues that are critical in guiding appropriate management of such patients.

OBSERVATIONS

The authors reported a patient with no significant medical history who presented with back pain, progressive lower extremity weakness, gait ataxia, and bowel and bladder incontinence. They discussed multimodality imaging for determining the presence of arachnoid webs, including magnetic resonance imaging, phase-contrast CSF flow study, computed tomography myelography, and intraoperative ultrasound. They also discussed the detailed anatomy of the spinal subarachnoid space and a plausible pathophysiological mechanism for dorsal arachnoid webs.

LESSONS

The authors report on a patient who underwent comprehensive imaging evaluation detailing the arachnoid web and whose subsequent anatomical localization and surgical treatment resulted in a full neurological recovery.

Compression médullaire par kystes arachnoïdiens

Spinal arachnoid cysts are considered to be rare entities, intradural locations are even less common. We report two cases of patients (two women aged 77- and 21-year-old) who presented spinal cord compression by intradural arachnoid cysts. For the second patient, repeated surgical procedures were necessary to improve the neurological status. After presenting the case reports, we expose the pathophysiological mechanisms and clinical features, and the surgical difficulties of treating this rare cause of spinal cord compression.

Spinal arachnoid cysts: clinical and radiological correlation with prognosis

The clinical and radiological findings in six extradural and nine intradural arachnoid cysts are discussed in relation to previous reports. Only two cysts failed to opacify during positive contrast myelography; in both cases Myodil was used and in one of them contrast medium had entered the cyst on delayed films taken at 24 h. Pain was always improved and generally cured by operation, only two patients having some residual backache. There was permanent improvement of neurological function in only eight cases. The factors associated with poor permanent recovery after surgical treatment were: 1) very marked thinning of the spinal cord by the cyst, and 2) relatively longer duration of paresis--only one case had paresis for under 2 years (mean 4.8 years) compared with only two cases for over 1 year (mean 2 years) in those with good recovery.