These cystic lesions are congenital.
Arachnoid cysts account for only 1% of all intracranial space-occupying lesions.
Intracranial cysts are classified as supratentorial, infratentorial, and supra-infratentorial (tentorial notch) 1).
50-66% occurring within the middle cranial fossa in most series. Ten percent occur in the suprasellar and quadrigeminal regions and approximately 5% each in the posterior fossa and over the frontal convexities
Supratentorial are divided into:
Quadrigeminal plate cistern
Many theories have been postulated for etiopathogenesis of arachnoid cysts. Various hypotheses are: entrapment of CSF in a diverticulum; CSF flow changes leading to arachnoid cell layer tears during the formation of various cisternae; during embryological separation (at around 15th week of gestation) of arachnoid from the dura mater 2).
Spontaneous intracystic hemorrhage in an arachnoid cyst is a rare complication (although hemorrhagic arachnoid cyst is well known in the clinical setting of trauma), which may present with symptoms of raised intracranial pressure (headache, vomiting, altered sensorium) or focal neurological deficits depending on the location and is an indication for surgery 3) 4).
Although complications such as intracystic, subdural, and extradural hematomas are well known after a trauma, spontaneous hemorrhage in an arachnoid cyst is a rare and serious complication with atypical imaging features on cross-sectional imaging and only less than ten cases are documented in the literature 5).
Surgery can be performed with a fairly low risk of complications and yields significant improvement in quality of life correlated to postoperative improvement in headache and dizziness. These findings may justify a more liberal approach to surgical treatment 6).
There is currently no consensus on the safety of sports participation for patients with an intracranial arachnoid cyst (AC).
A survey was prospectively administered to 185 patients with ACs during a 46-month period at a single institution. Cyst size and location, treatment, sports participation, and any injuries were recorded. Eighty patients completed at least 1 subsequent survey following their initial entry into the registry, and these patients were included in a prospective registry with a mean prospective follow-up interval of 15.9 ± 8.8 months.
A total 112 patients with ACs participated in 261 sports for a cumulative duration of 4410 months or 1470 seasons. Of these, 94 patients participated in 190 contact sports for a cumulative duration of 2818 months or 939 seasons. There were no serious or catastrophic neurological injuries. Two patients presented with symptomatic subdural hygromas following minor sports injuries. In the prospective cohort, there were no neurological injuries
Permanent or catastrophic neurological injuries are very unusual in AC patients who participate in athletic activities. In most cases, sports participation by these patients is safe 7).