Adhesive arachnoiditis is a rare yet serious complication that may occur following subarachnoid hemorrhage (SAH). In this circumstance, it is mainly due to ruptured vertebral artery (VA) or posterior inferior artery (PICA) aneurysms. It disrupts cerebrospinal fluid (CSF) flow leading to complications such as spinal arachnoiditis, syringomyelia, trapped 4th ventricle, or a combination of these conditions. Evidence for effective treatment strategies is currently limited. We aimed to review the epidemiology, clinical characteristics, treatment, complications, outcomes, and prognosis of cranio-vertebral junction and spinal adhesive arachnoiditis resulting from ruptured VA and PICA aneurysms.

This study involved a comprehensive literature review and complemented by our own case. We focused on adult cases of arachnoiditis, syringomyelia, and trapped 4th ventricle with SAH caused by ruptured VA or PICA aneurysms, excluding cases unrelated to these aneurysms and those with insufficient data.

The study included 22 patients, with a mean age of 52.4 years. Symptoms commonly manifest within the first year after SAH and timely diagnosis requires a high index of suspicion. Treatment approaches included lysis of adhesions and various shunt procedures. Most patients showed improvement post-treatment, though symptom recurrence is significant.

Adhesive arachnoiditis is a critical complication following SAH, most commonly from ruptured VA and PICA aneurysms. Early detection and individualized treatment based on the type of arachnoiditis and CSF flow impact are crucial for effective management. This study underscores the need for tailored treatment strategies and further research in this field.