Intracranial arachnoid cysts and epilepsy in children: Should this be treated surgically? Our 29-year experience and review of the literature

INTRODUCTION AND OBJECTIVE

Arachnoid cysts (ACs) are relatively frequent lesions related to different neurological symptoms, being mostly incidentally diagnosed. This study aims to clarify whether AC surgery in epileptic patients is useful in their treatment.

MATERIAL AND METHODS

The patients registered in the database of the Neuropediatrics Section from May 1990 to August 2019 are analyzed retrospectively. Patients in whom the diagnosis of ACs and epilepsy coincide are studied. The location, size and number of ACs, neurological development, age at diagnosis, follow-up time, the performance of surgery on the cyst, evolution, anatomical relationship between brain electrical activity and location of AC, and type of epilepsy are analyzed.

RESULTS

After analyzing the database, we found 1881 patients diagnosed with epilepsy, of which 25 had at least one intracranial AC. In 9 of the patients, cerebral or genetic pathologies were the cause of epilepsy. Of the other 16, only 2 patients showed that the type of epilepsy and the epileptogenic focus coincided with the location of the AC; one of them was surgically treated without success, and the other one remained asymptomatic without receiving medical or surgical treatment.

CONCLUSIONS

Although it is necessary to design a prospective study to establish causality, the results of our research and the available literature suggest that there is no causal relationship between the presence of ACs and epilepsy. The study and treatment of these patients should be carried out in a multidisciplinary epilepsy surgery unit, without initially assuming that the AC is the cause of epilepsy.

Intracranial arachnoid cysts and epilepsy in children: Should this be treated surgically? Our 29-year experience and review of the literature

INTRODUCTION AND OBJECTIVE

Arachnoid cysts (ACs) are relatively frequent lesions related to different neurological symptoms, being mostly incidentally diagnosed. This study aims to clarify whether AC surgery in epileptic patients is useful in their treatment.

MATERIAL AND METHODS

The patients registered in the database of the Neuropediatrics Section from May 1990 to August 2019 are analyzed retrospectively. Patients in whom the diagnosis of ACs and epilepsy coincide are studied. The location, size and number of ACs, neurological development, age at diagnosis, follow-up time, the performance of surgery on the cyst, evolution, anatomical relationship between brain electrical activity and location of AC, and type of epilepsy are analyzed.

RESULTS

After analyzing the database, we found 1881 patients diagnosed with epilepsy, of which 25 had at least one intracranial AC. In 9 of the patients, cerebral or genetic pathologies were the cause of epilepsy. Of the other 16, only 2 patients showed that the type of epilepsy and the epileptogenic focus coincided with the location of the AC; one of them was surgically treated without success, and the other one remained asymptomatic without receiving medical or surgical treatment.

CONCLUSIONS

Although it is necessary to design a prospective study to establish causality, the results of our research and the available literature suggest that there is no causal relationship between the presence of ACs and epilepsy. The study and treatment of these patients should be carried out in a multidisciplinary epilepsy surgery unit, without initially assuming that the AC is the cause of epilepsy.

[Arachnoid cysts: Embriology and pathology]

There is still great controversy surrounding the origin of the arachnoid cyst. The most accepted theory in the case of congenital cysts explains how they are formed from an anomalous development of the arachnoid membrane, which is unfolded allowing the accumulation of cerebrospinal fluid inside and creating a cyst. This theory seems to explain the origin of convexity and sylvian cistern arachnoid cysts, whereas those in other locations might be due to other mechanisms. In the anatomopathological analysis, the arachnoid cyst wall can be seen as having few differences from normal, although thickened due to an increase quantity of collagenous material. A description of the embryological development of the arachnoid layer and cyst formation is presented, describing the main anatomopathological findings.

[Epidemiology and classification of arachnoid cysts in children]

The prevalence of arachnoid cysts in children is 1-3%. They are more frequent in boys. They can be located intracranially or in the spine. Intracranial cysts are classified as supratentorial, infratentorial, and supra-infratentorial (tentorial notch). Supratentorial are divided into middle cranial fossa, convexity, inter-hemisferic, sellar region, and intraventricular. Infratentorial are classified into supracerebellar, infracerebellar, hemispheric, clivus, and cerebellopontine angle. Finally spinal arachnoid cysts are classified taking into account whether they are extra- or intradural, and nerve root involvement.