Compressive myelopathy secondary to posthemorragic arachnoiditis: Case report and literature review

Abstract

Background: Spinal arachnoiditis is an arachnoid inflammatory process frequently caused by infection or spinal surgery; there are different degrees of severity, including arachnoid thickening and severe adhesive lesions that can lead to the development of arachnoid cysts. Non-traumatic subarachnoid haemorrhage (ntSAH) is a relatively uncommon cause of arachnoiditis; further complication with spinal cord compression (SCC) is even more unusual.

Method: we describe a 70-year-old female, with SCC caused by arachnoid cysts. Her medical past history was relevant for an episode of ntSAH after rupture of a posterior communicating artery aneurysm, eight months prior to the onset of symptoms. We also present a literature review of previous published cases.

Results: we selected 23 articles with 24 case reports. A noticeable female predominance (11:1) was observed. It is more common between the fourth and fifth decades. The majority of cases (58 %) were secondary to aneurysmal SAH due to rupture of a posterior circulation aneurysm. The most common location of the cyst is in the cervicothoracic spine. The average time between the initial bleeding and symptom development is 3-6 months. The most frequently described treatment is laminectomy and marsupialization of the cyst, but reports show a high recurrence rate.

Conclusions: ntSAH is an uncommon aetiology of arachnoiditis and arachnoid cysts. SCC from arachnoid cysts secondary to ntSAH is exceptional. Treatment through laminectomy has a relatively high recurrence rate (33 %). We present different hypotheses to try to explain how the alteration of cerebrospinal fluid (CSF) dynamics after ntSAH can lead to arachnoid cyst development and SCC. Although the small number of cases included in the present series precludes us to draw definite conclusions, ventriculoperitoneal shunt (VPS) placement can be considered as an alternative treatment in the management of known ntSAH patients that present recurrent symptomatic arachnoid cysts.

Keywords: Arachnoid cyst; Arachnoiditis; Myelopathy; Subarachnoid haemorrhage.