Abstract
Background and Study Aims 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.
Methods and Patients 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.
Results 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%).
Conclusion The AZM challenge may support the clinical decision to recommend surgery in those
patients whose symptoms improve during AZM therapy.
Keywords
surgery - endoscopic - shunt - acetazolamide - arachnoid cyst
