(Código CIE-9-CM: 348.0)
Cyst arachnoid, also known as cysts leptomení & shy; ngeos.
Arachnoid cysts (QA) are pathological structures Featu & shy; benign sticas that Scatter symbol & shy; masters defined as filled cavities li & shy; I clear liquid similar to li & shy; & shy cerebral spinal liquid; deo (LCR), contained within a membrane indistinguishable histologically healthy arachnoid.
Occur during the division of the arachnoid.
The most accepted hypothesis speaks of changes in the separation of endomenix in the third quarter of perí & shy; odo neonatal. The membrane is endomenix mesenchymal tissue surrounding the neural tube. In the third quarter, when the roof of the fourth breaks Ventri & shy; ass, CSF pressure waves flowing through it, the dissected into two layers and result pial, arachnoid and subarachnoid space. Alterations of this mechanism Scatter symbol & shy; an lead to the formation of separate cavities that, growth in, formarí & shy; an cysts.
Other hypotheses are saying that are secondary to focal brain hypoplasia, in which occupy the space provided or produced by alterations of the secretion of substances from the subarachnoid space to the venous system. Also, to explain the posterior cyst growth have raised several TEORI & shy; as; including, the most accepted, because there are cases where it has been demonstrated in vivo, is the formation of valve mechanisms . Have also been described in the literature in some cases related cysts infections meningeal and injuries, called secondary, as opposed to those for which the cause is unknown and suspected congenital malformation, and designated primary.
Really it is intraaracnoideos cysts. When diagnosed at the level of middle fossa were called ” yes & shy; ndrome ” lobe agenesis temporal. (This term is now obsolete).
Others are caused by trauma.
An fracture Simple linear, without immediate complications, can cause the development of a cyst arachnoid, hence & shy; you must maintain proper monitoring of the evolution of consolidation fracture and an etiologic alert to the emergence of clini & shy; neurological nica.
They provide a diagnosis you & shy; peak childhood, especially in the first two years of life, which represent approximately 1% of intracranial expansive lesions. The most common locations found in various series are the Sylvian fissure and posterior fossa.
5 by 1000 in autopsias.son injuries Featu & shy; sticas childhood, slightly more common in males.
Also found at the spinal level, although they are rare.
- Cisura de silvio 49%
- APC 11%
- Supracolicular 10%
- Vermiano 9%
- Sellar and suprasellar 9%
- Interhemisférico 5%
- Convexity 4%
- Clivus 3%
Simple cysts: Li & shy; cell line appear to be capable of secretion CSF. The cysts of the middle fossa speak exclusively of this type
Complex cysts that may also contain glia, epéndimo, and other types of tissue.
Presentation CLI & shy; nica
The sintomatologí & shy; varies according to the filesystem nervous central compress, the most striking are other & shy; focal symptoms with signs intracranial hypertension, as are headache (pain de cabeza), hemiparesis,diplopia (double vision), irritability, mood swings, apatí­a (emotionless), and impaired intellectual performance.
Trench Media suprasellar with fuzzy supra or infratentorial hydrocephalus hydrocephalus
Epilepsy,headache,hemiparesia HTE,Craneomegalia,development Tardi & shy; or,loss of visual acuity,precocious puberty HTE,craneomegalia,development Tardi & shy; or
The Mayori & shy; to cysts are symptomatic in infancy.
Can be diagnosed by the presence of:
- Yes & shy; symptoms of increased intracranial pressure (Headache, sickness…)
- Sudden deterioration: due to bleeding (in cyst or subdural): pit medial cysts are prone to bleeding due to the increased possibility of rupture of bridging veins; due to rupture of the cyst
- Protrusion in the skull
- Focal neurological signs.
- Incidental finding.
- Hydrocephalus (Probably due to compression of the third Ventri & shy; ass)
- Yes & shy; endocrine symptoms: occurring in a 60%. Includes precocious puberty.
- Visual impairment
- In posterior fossa usually produce other & shy; & shy nonspeci symptoms, such as hearing loss and tinnitus tists sometimes even difficult to distinguish from Meniere's disease and most Featu & shy; stico usually cerebellar ataxias.
Are diagnosed primarily by TAC.
The ideal method of diffusion MRI sequences (Maybe it will raise the differential diagnosis with epidermoid cysts or neoplastic hemangioblastomas).
- Astrocitomas you & shy; STICOS.
- Wemer cistern
- Hidatí & shy cyst doctor – Cisticercosis
- Myocardial old crebral
- Hollow of Li & shy; NEA Media.
It is recommended to treat only those producing other & shy; symptoms regardless of the location and size. Treatment is still controversial.
Therapeutic options have endoscopic fenestration or craniotomy into the ventricle or subarachnoid space and the implantation of a shunt.
Probably the best treatment consists in the derivation of cyst peritoneum.
Method Advantages Disadvantages
Aspiration- drill and fast Recurrence
Craneotomí & shy; a with excision of the wall ere & shy; sticay fenestration to subarachnoid or ventricular space allows inspection of the cyst and vascular structures. Evita in some cases permanent shunt. Possible re-accumulation and more invasive.
Cystoperitoneal Simple Derivation Procedure Unit Shunt and risks of carrying Shunt.
Dr. J. Sales Llopis
Service Neurocirugí & shy; at the University General Hospital of Alicante.