INTRODUCTION

Within infancy and youth, the calvaria (skull vault) expands to create room for the growing brain. The cranial sutures, which are tiny fissures of developing mesenchyme located between numerous bones, are where this growth primarily occurs. The metopic and sagittal sutures, respectively, split the frontal and parietal bones midway. Coronal sutures separate the frontal and parietal bones, and lambdoid sutures separate the parietal bones from the lone occipital bone [1].

The condition known as cranial synostosis is the early fusion of one or more of the cranial sutures; secondary deformation of the skull shape is caused by a confluence of insufficient growth parallel to the fused suture and compensatory overgrowth at the non-fused sutures [2]. If left untreated, craniosynostosis can result in probable cranial growth restriction as well as subsequent cranial and facial deformities [3].

It is well-established that the craniofacial population is more susceptible to neurocognitive deficiencies than the general population, including lower generalized intelligence quotients, learning challenges, language delays, and behavioral issues. While the exact cause of this is unknown, there is evidence that cranial growth limitation and the subsequent intracranial pressure play a part in craniocerebral disproportion [4].

A recent systematic review and meta-analysis documented that there are 84,665 children born with craniosynostosis worldwide annually, including 72,857 children with non-syndromic craniosynostosis [5]. Infant surgery is frequently performed to modify the abnormal form of the skull, lower the risk of intracranial hypertension, and improve psychosocial health [3].

Many surgeons elect to perform their procedures at a young age to benefit from the beneficial effects of brain growth on skull shape. If there is any sign of raised intracranial pressure, such as enlarged fontanelles, progressive optic atrophy, convulsions, or multiple-suture synostosis, most surgeons perform surgery as quickly as possible [6]. There is a lack of literature reporting the complications of craniosynostosis, especially epileptic seizures, and most of them are included in clinical series [7, 8].

As far as we are aware, there has never been a systematic review that looked at the prevalence of epilepsy in people with craniosynostosis. This study's objective is to present patient demographics, the prevalence of epilepsy, and potential causes of the condition. Our study included both pre- and post-operative epileptic seizures.

MATERIALS AND METHODS

This systematic review was conducted following the demonstrated guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses, PRISMA).

Study Design

This was a systematic review and meta-analysis.

Study Duration

From July to August 2022.

Study Condition

The published research on patients with craniosynostosis who experience epileptic seizures and those who have corrective surgery but experience post-operative seizures is examined in this study.

Search Strategy

To find the relevant literature, a thorough literature search was conducted in five main databases, including PubMed, Web of Science, Science Direct, EBSCO, and Cochrane Library. Our search was restricted to the English language, and it was customized as needed for each database. The following keywords, which were converted into Mesh terms in PubMed, were used to identify the appropriate studies: "craniosynostosis," "syndromic craniosynostosis," "non-syndromic craniosynostosis," "Epilepsy," "seizures," "epileptic seizures," and "convulsions." The appropriate keywords were paired with "OR" and "AND" Boolean operators. The search results comprised English, full-text publications, freely available articles, and human trials.

Selection Criteria

Our review comprised the studies with the following criteria:

• Mainly cohort and retrospective cohort studies and study designs that provided qualitative or quantitative data about the incidence of pre-and post-operative epilepsy among patients with craniosynostosis.

Exclusion criteria included the following:

• Studies not conducted in the English language.
• Studies with no free access.

Data Extraction

To identify the duplicate components of the search strategy results, we employed Rayyan (QCRI) [9]. By filtering the combined search results according to a set of inclusion/exclusion criteria, the researchers assessed the adequacy of the titles and abstracts. The entire texts of the papers that met the criteria for inclusion were evaluated by the reviewers. To resolve any discrepancies, the writers had INS discussions. The eligible study was added using a data extraction form that was produced. The study's names, authors, year, design, population, participant count, gender, prevalence of pre-and post-operative epilepsy, type of craniosynostosis, and significant findings were all extracted by the authors.

Risk of Bias Assessment

To evaluate the caliber of the included research, the qualitative data synthesis employed the ROBINS-I technique for non-randomized studies [10]. The reviewers looked into and corrected any anomalies in the quality evaluation.

Strategy for Data Synthesis

Summary tables with the information gathered from the eligible studies were produced to give a qualitative overview of the included study components and result data. After the systematic review's data extraction process was completed, choices were made regarding how to make the most of the data present in the included study papers. Studies that complied with the full-text standards for inclusion but lacked information on the prevalence of epileptic seizures were disregarded.

RESULTS AND DISCUSSION

Search Results

53 duplicate study articles out of a total of 460 were eliminated after the comprehensive search. 290 studies were removed after 407 studies had their titles and abstracts screened. Only seven articles out of the 117 reports that were sought for retrieval were not found. In the end, 110 studies were screened for full-text evaluation. However, 78 studies were disqualified due to the wrong study outcomes; 21 studies were disqualified due to a lack of information regarding the frequency of epileptic seizures; and 11 studies were disqualified due to the incorrect population type. This systematic review contained ten appropriate study papers. Figure 1 depicts a summary of the study selection procedure.

Characteristics of the Included Studies

A total of 11 studies were included in this review, with 21456 patients diagnosed with craniosynostosis, and more than half of them were males. Eight studies were conducted in the United States (USA) [10-17], one in Brazil [18], one in India [19], and one in Turkey [20]. We found that the non-syndromic craniosynostosis weighed much more than the syndromic incidence. Three studies reported preoperative/history of epileptic seizures; the highest rate (12.2%) was reported by Ongun et al. [20], followed by Agochukwu et al. (12%) [14], and the lowest rate (2.5%) was reported by Stanbouly et al., [15]. Post-operative epilepsy was reported in seven studies; the highest rate (12.2%) [20] and the lowest (0.24%) [11]. Seven studies [10, 12-14, 17, 18, 20] found a high risk of bias, while four studies reported a moderate risk [11, 15, 16, 19].