Intracranial arachnoid cysts


Intracranial arachnoid cysts: A rare disorder involving a fluid-filled cysts on the arachnoid membrane which is one of the thin layers of tissue that form a membrane which covers the brain. The type and severity of symptoms is determined by the size and location of the cyst.


The list of signs and symptoms mentioned in various sources for Intracranial arachnoid cysts includes the 17 symptoms listed below: * Arachnoid cyst * Headache * Nausea * Seizures * Impaired hearing * Vision disturbance * Vomiting * Vertigo * Problems with balance * Walking difficulty * Enlarged head * Head nodding * Increased intracranial pressure * Behavioral changes * Developmental delay * Confusion * Forgetfulness


Primary or congenital arachnoid cysts are maldevelopmental anomalies and should be differentiated from secondary arachnoid cysts that are rare and result from a variety of such etiologies as trauma and infection. The cyst has an incessant tendency to grow or recur but the growing mechanism is still a mystery and the mechanism by which they expand is not fully understood.


Routine evaluation with CT or MRI scans is usually satisfactory in identifying the cyst which is seen as a smooth bordered cystic mass composed of a density similar to that of CSF and does not show enhancement with contrast administration. Detection of the cyst is even possible prenatally by ultrasound. Expansion of the nearby bone by remodeling is usually seen, confirming their chronic nature. Increasingly, scans of the brain (done for other reasons, such as assessment of head injury or persistent headache) discover the presence of an arachnoid cyst as an incidental finding.


There is a wide variation in the natural course and the clinical manifestations of congenital intracranial arachnoid cysts. Nevertheless, there has also been a considerable controversy regarding the indications, choice and timing of surgical intervention. While there is a common consensus that small cysts with minimal symptoms should be treated conservatively with regular clinical and radiological follow-up, it is also agreed that large space-occupying cysts that exert a mass effect or those causing neurological impairment require surgical intervention as the potential for hindering normal development and function of the adjacent brain in this group outweighs the risk of operative treatment. The goals of surgical treatment are to drain the cyst and to prevent the recollection of fluid, allowing for re-expansion of the compressed neighboring neural tissue. However, the optimum surgical modality to achieve these goals has been a subject of debate, mostly due to the inherent risks associated with each surgical modality. The two main surgical modalities by which intracranial arachnoid cysts have been most commonly treated are formal craniotomy with excision/marsupialization of the cyst into the subarachnoid space and cysto-peritoneal shunting. While cystoperitoneal shunting implies long-term shunt dependence and complications such as shunt obstruction or infection, formal craniotomy, however, involves injurious "transcortical" surgical dissection and a significant degree of brain retraction, which in turn may result in undesirable perioperative morbidity and inability to completely excise the cyst due to a limited exposure. Other operative procedures that have been recommended for treatment of arachnoid cysts include stereotactic cyst aspiration, cysto-cisternostomy and ventriculocystostomy.


* Neurology (Brain/CNS Specialists): o Neurology (Brain/CNS Specialists) o Pediatric Neurology (Child Brain Specialist) o Pediatric Neurosurgery (Child Neurosurgeon) o Clinical Neurophysiology o Neurodevelopment Disabilities o Neurosurgery o Neuromusculoskeletal Medicine o Neuroradiology o Vascular Neurology o Neuropathology o Otology / Neurotology (Ear/Hearing Specialists)