Chapter 16 - SPECT Studies in Patients With Arachnoid Cysts

Abstract

At present, numerous patients are found to harbor an intracranial arachnoid cyst (AC). In the recent past, many of these cysts were treated with some type of surgery, such as cystoperitoneal shunting or cyst fenestration, based only on the presence of the cyst in neuroimaging studies. Indications for neurosurgical treatment of ACs include direct brain compression, distortion of intracranial structures, hydrocephalus, and intracranial hypertension. The ample use of new neuroimaging methods has led to the straightforward diagnosis of many cysts that apparently are producing no harm to the brain, which are known as incidental ACs. On the other hand, we have witnessed during the last decades the appearance of a large number of publications dealing with the complications derived from AC treatments, mostly after cyst shunting. This led many authors to advise restricting surgical treatment to cases that present clear clinical and laboratory features of brain dysfunction to prevent hazards derived from the surgeries. Even considering the low risks of surgical treatments, some complications seem to be avoidable utilizing stricter indications. This more conservative approach has motivated some authors to suggest that certain complications would not have occurred if many ACs had never been operated on. A main concern refers to “preventive surgery” directed at avoiding the eventual damage caused by the cysts on the developing brain of children. Another conflicting issue arises on surgical indications in patients with epilepsy, neurocognitive, and behavioral symptoms. Accordingly, many investigators have focused their research on the development of dependable diagnostic tests that may help in the decision-making process. In this chapter, we will deal with the value of single-photon emission computerized tomography on early detection of the possible brain damage that these cysts may cause.