The Acetazolamide Challenge: A Tool for Surgical Decision Making and Predicting Surgical Outcome in Patients with Arachnoid Cysts

Abstract

Arachnoid cysts (ACs) are benign congenital malformations of the arachnoid that may present with either localizing or nonspecific symptoms. ACs with mass effect are detected frequently in asymptomatic patients. Conversely, symptomatic patients may present without imaging signs of a focal mass effect that emphasizes the difficulty of relying on imaging as the sole criteria in surgical selection. We hypothesize that symptomatic AC may be related to the elevated fluid pressure within the cyst on surrounding structures. Thus reducing the amount of fluid in the cyst or surrounding cerebrospinal fluid (CSF) by using acetazolamide (AZM), a carbonic anhydrase inhibitor known to reduce CSF production, might mimic surgical decompression and therefore could serve as a decision-making tool in patients with ACs. A total of 103 patients with radiographically proven ACs were initially identified. Twenty (19.4%) were symptomatic and underwent a trial of oral AZM. Data were collected meeting inclusion/exclusion criteria for this cohort study and analyzed retrospectively/prospectively. Overall, 17 patients were able to tolerate the AZM and had at least some subjective improvement in their symptoms during the AZM challenge and underwent surgical therapy. Surgery was beneficial in 16 patients (94.1%). Following surgery, symptoms resolved in 13 patients (76.5%) and improved in 3 (17.6%). The AZM challenge may support the clinical decision to recommend surgery in those patients whose symptoms improve during AZM therapy.

Brain Edema Formation and Functional Outcome After Surgical Decompression in Murine Closed Head Injury Are Modulated by Acetazolamide Administration

“…Improvement of the posttraumatic course of animals could be achieved by only a single dose of the substance. While ACZ has been widely used in neurosurgical practice (15–22, 80, 84, 85), translating our treatment regime into clinical practice is hampered by a couple of shortcomings that need to be addressed in follow-up studies. First, while the CHI was deliberately chosen to perform DC on the not previously trephined skull, and to demonstrate a well-delineated injury epicenter by MRI (31, 49), this model does not necessarily demonstrates all the features of severe head trauma as seen in clinical routine.…”

Correlation of spinal cord injury with development of spinal arachnoid cysts: Two case reports

“…These sequestered pockets of fluid lead to further disruption of normal CSF flow and are thus capable of expanding or producing associated arachnoid cysts along the path of least resistance. SAC give rise to compression of the spinal cord secondary to the complex CSF flow within the spinal canal ( 2 , 7 ). Cystic enlargement, secondary to fluctuations in CSF pressure (Valsalva manoeuvre) has been explained by a 1-way ball-valve effect at the cyst neck ( 2 , 8 ).…”

“…The role of acetazolamide (AZM), a carbonic anhydrase inhibitor known to reduce CSF production, is uncertain ( 7 ). Symptomatic SAC may be related to the elevated fluid pressure within the cyst on surrounding structures, thus reducing the amount of fluid in the cyst or surrounding CSF may hold promise.…”

“…Symptomatic SAC may be related to the elevated fluid pressure within the cyst on surrounding structures, thus reducing the amount of fluid in the cyst or surrounding CSF may hold promise. This might mimic surgical decompression, and therefore the AZM challenge could serve as a decisionmaking tool to recommend surgery in those patients whose symptoms improve during AZM therapy ( 7 ).…”