Arachnoid cysts are a frequent finding on intracranial imaging. The prevalence and natural history of these cysts in adults are not well defined.
We retrospectively reviewed the electronic medical records of a consecutive series of adults who underwent brain MRI over a 12-year interval to identify those with arachnoid cysts. The MRI studies were reviewed to confirm the diagnosis. For those patients with arachnoid cysts, we evaluated presenting symptoms, cyst size, and cyst location. Patients with more than 6 months' clinical and imaging follow-up were included in a natural history analysis.
A total of 48,417 patients underwent brain MRI over the study period. Arachnoid cysts were identified in 661 patients (1.4%). Men had a higher prevalence than women (p < 0.0001). Multiple arachnoid cysts occurred in 30 patients. The most common locations were middle fossa (34%), retrocerebellar (33%), and convexity (14%). Middle fossa cysts were predominantly left-sided (70%, p < 0.001). Thirty-five patients were considered symptomatic and 24 underwent surgical treatment. Sellar and suprasellar cysts were more likely to be considered symptomatic (p < 0.0001). Middle fossa cysts were less likely to be considered symptomatic (p = 0.01. The criteria for natural history analysis were met in 203 patients with a total of 213 cysts. After a mean follow-up of 3.8 ± 2.8 years (for this subgroup), 5 cysts (2.3%) increased in size and 2 cysts decreased in size (0.9%). Only 2 patients developed new or worsening symptoms over the follow-up period.
Arachnoid cysts are a common incidental finding on intracranial imaging in all age groups. Although arachnoid cysts are symptomatic in a small number of patients, they are associated with a benign natural history for those presenting without symptoms.
Abbreviation used in this paper:CPA = cerebellopontine angle.
Address correspondence to: Cormac O. Maher, M.D., Department of Neurosurgery, University of Michigan, 1500 East Medical Center Drive, Room 3552 Taubman Center, Ann Arbor, Michigan 48109-5338. email: firstname.lastname@example.org.
Please include this information when citing this paper: published online November 9, 2012; DOI: 10.3171/2012.10.JNS12548.
BoutarbouchMEl OuahabiARifiLArkhaYDerrazSEl KhamlichiA: Management of intracranial arachnoid cysts: institutional experience with initial 32 cases and review of the literature. Clin Neurol Neurosurg110:1–72008
de-Melo-NetoVLLopesFLMagalhãesFVDominguesRCHallakJECrippaJA: Anterior cingulate cortex activation as a trait of panic disorder in a patient with a temporal arachnoid cyst. Prog Neuropsychopharmacol Biol Psychiatry33:1565–15672009
GalassiETognettiFGaistGFagioliLFrankFFrankG: CT scan and metrizamide CT cisternography in arachnoid cysts of the middle cranial fossa: classification and pathophysiological aspects. Surg Neurol17:363–3691982
HellandCAWesterK: A population-based study of intracranial arachnoid cysts: clinical and neuroimaging outcomes following surgical cyst decompression in adults. J Neurol Neurosurg Psychiatry78:1129–11352007
Martínez-LageJFValentíJAPiquerasCRuiz-EspejoAMRománFNuño de la RosaJA: Functional assessment of intracranial arachnoid cysts with TC99 m-HMPAO SPECT: a preliminary report. Childs Nerv Syst22:1091–10972006
MoriKYamamotoTHorinakaNMaedaM: Arachnoid cyst is a risk factor for chronic subdural hematoma in juveniles: twelve cases of chronic subdural hematoma associated with arachnoid cyst. J Neurotrauma19:1017–10272002
MottoleseCSzathmariASimonEGingueneCRicci-FranchiACHermierM: The parallel use of endoscopic fenestration and a cystoperitoneal shunt with programmable valve to treat arachnoid cysts: experience and hypothesis. Clinical article. J Neurosurg Pediatr5:408–4142010
ParschCSKraussJHofmannEMeixensbergerJRoosenK: Arachnoid cysts associated with subdural hematomas and hygromas: analysis of 16 cases, long-term follow-up, and review of the literature. Neurosurgery40:483–4901997
SunTZhaoJ: Multiple saccular aneurysms of the extracranial and intracranial internal carotid artery associated with convexobasia and arachnoid cyst in a 6-year-old boy: a case report. Childs Nerv Syst26:113–1162010
TalamontiGD'AlibertiGPicanoMDebernardiAColliceM: Intracranial cysts containing cerebrospinal fluid-like fluid: results of endoscopic neurosurgery in a series of 64 consecutive cases. Neurosurgery68:788–8032011
TamburriniGDal FabbroMDi RoccoC: Sylvian fissure arachnoid cysts: a survey on their diagnostic workout and practical management. Childs Nerv Syst24:593–6042008. (Erratum in Childs Nerv Syst 24:635 2008)
WangYQiuBLiPChengPLiGLiX: Multifocal intraparenchymal Langerhans' cell histiocytosis concomitant with an arachnoid cyst in a child: case report and review of the literature. J Child Neurol27:767–7782012