Epidemiology of Arachnoid Cysts of the Head and Spine in Children
Incidence and Prevalence
1% of intracranial mass lesions: Arachnoid cysts account for approximately 1% of intracranial mass lesions.
Middle fossa most common: The most common location is the middle fossa (50% of all cysts), with a left side predominance. Other locations include frontal convexity and posterior fossa.
Rare lesions: Both intra- and extradural cysts account for a relatively small number of the already rare number of arachnoid cysts. They are predominantly posterior to the cord and mostly in the cervical region, although some are seen in the lumbar region, as well.
Early childhood: Cranial cysts usually present in early childhood.
Any age: Spinal cysts can present at any age, although thoracic cysts predominantly present during adolescence.
Male predominance: Arachnoid cysts may be up to four times more common in boys.
Intradural: No gender predominance is apparent.
Extradural: Extradural arachnoid cysts are more common in males.
Not a factor
Relationships to Other Disease States and Syndromes
Hydrocephalus: Cranial arachnoid cysts may be related to hydrocephalus or anomalous CSF circulation.
GAT 1: Bitemporal arachnoid cysts may be associated with a congenital metabolic disorder, GAT 1, which may make surgery hazardous due to a metabolic crisis triggered by anesthesia (14).
Inflammation: Cysts may be due to loculated CSF secondary to scarring and inflammation from hemorrhage or infection.
Associated syndromes: Incidence is seen in conjunction with Down syndrome, mucopolysaccharidosis, schizencephaly, and neurofibromatosis.