arachnoid cyst

Patients with arachnoid cysts may never show symptoms, even in some cases where the cyst is large. Therefore, while the presence of symptoms may provoke further clinical investigation, symptoms independent of further data cannot—and should not—be interpreted as evidence of a cyst's existence, size, location, or potential functional impact on the patient.{{citation needed|date=July 2021}}

Symptoms vary by the size and location of the cyst(s), though small cysts usually have no symptoms and are discovered only incidentally. On the other hand, a number of symptoms may result from large cysts:

• Cranial deformation or macrocephaly (enlargement of the head), particularly in childrenBarker RA, Scolding N, Rowe D, Larner AJ. The A-Z of Neurological Practice: A Guide to Clinical Neurology Cambridge University Press 2005 Jan 10, p61. ({{ISBN|0-521-62960-8}})
• Cysts in the suprasellar region in children have presented as bobbing and nodding of the head called bobble-head doll syndrome.
• Cysts in the left middle cranial fossa have been associated with ADHD in a study on affected children.{{cite journal | vauthors = Millichap JG | title = Temporal lobe arachnoid cyst-attention deficit disorder syndrome: role of the electroencephalogram in diagnosis | journal = Neurology | volume = 48 | issue = 5 | pages = 1435–9 | date = May 1997 | pmid = 9153486 | doi = 10.1212/wnl.48.5.1435 | s2cid = 28361288 }}
• Headaches. A patient experiencing a headache does not necessarily have an arachnoid cyst.
• In a 2002 study involving 78 patients with a migraine or tension-type headache, CT scans showed abnormalities in over a third of the patients, though arachnoid cysts only accounted for 2.6% of patients in this study.{{cite journal | author = Valença MM, Valença LP, Menezes TL | title = Computed tomography scan of the head in patients with migraine or tension-type headache | journal = Arq Neuropsiquiatr | volume = 60| issue = 3A| pages = 542–7| pmid = 12244387 | date = September 2002 | doi = 10.1590/s0004-282x2002000400005 | doi-access = free }}
• A study found 18% of patients with intracranial arachnoid cysts had non-specific headaches. The cyst was in the temporal location in 75% of these cases.Cameron AD. "Psychotic phenomena with migraine and an arachnoid cyst", Progress in Neurology and Psychiatry 2002 Mar-Apr 6(2) [http://www.escriber.com/Progress/Features.asp?Action=View&Archive=True&ID=67&GroupID=&Page=11 http://www.escriber.com/Progress/Features.asp? Action=View&Archive=True&ID=67&GroupID=&Page=11] {{webarchive |url=https://web.archive.org/web/20070928042449/http://www.escriber.com/Progress/Features.asp?Action=View&Archive=True&ID=67&GroupID=&Page=11 |date=September 28, 2007 }}
• Seizures
• Hydrocephalus (excessive accumulation of cerebrospinal fluid)
• Increased intracranial pressure
• Developmental delay
• Behavioral changes
• Nausea
• Dysdiadokinesis
• Hemiparesis (weakness or paralysis on one side of the body)
• Ataxia (lack of muscle control)
• Musical hallucination{{cite journal | vauthors = Griffiths TD | title = Musical hallucinosis in acquired deafness. Phenomenology and brain substrate | journal = Brain | volume = 123 | issue = 10| pages = 2065–76 | date = October 2000 | pmid = 11004124 | doi = 10.1093/brain/123.10.2065 | doi-access = free }}
• Pre-senile dementia,Richards G, Lusznat RM. "An arachnoid cyst in a patient with pre-senile dementia", Progress in Neurology and Psychiatry, 2001 May–June;5(3) [http://www.escriber.com/Progress/Features.asp?Action=View&Archive=True&ID=29&GroupID=&Page=18 http://www.escriber.com/Progress/Features.asp? Action=View&Archive=True&ID=29&GroupID=&Page=18] {{webarchive |url=https://web.archive.org/web/20070928042438/http://www.escriber.com/Progress/Features.asp?Action=View&Archive=True&ID=29&GroupID=&Page=18 |date=September 28, 2007 }} a condition often associated with Alzheimer's disease
• In elderly patients (>80 years old) symptoms were similar to chronic subdural hematoma or normal pressure hydrocephalus:{{cite journal | author = Yamakawa H, Ohkuma A, Hattori T, Niikawa S, Kobayashi H | year = 1991 | title = Primary intracranial arachnoid cyst in the elderly: a survey on 39 cases | journal = Acta Neurochir (Wien) | volume = 113 | issue = 1–2| pages = 42–7 | pmid = 1799142 | doi = 10.1007/bf01402113 | s2cid = 24540942 }}
• Dementia
• Urinary incontinence
• Hemiparesis
• Headache
• Seizures

• A supratentorial arachnoid cyst can mimic a Ménière's disease attack.{{cite journal | vauthors = Buongiorno G, Ricca G | title = Supratentorial arachnoid cyst mimicking a Ménière's disease attack | journal = J Laryngol Otol | volume = 117 | issue = 9 | pages = 728–30 | date = September 2003 | pmid = 14561365 | doi = 10.1258/002221503322334602 | s2cid = 26032192 }}
• Frontal arachnoid cysts have been associated with depression.Cummings JL, Mega MS. Neuropsychiatry and Behavioral Neuroscience, Oxford University Press, USA; 2Rev Ed, 2003 Jan 23;208. ({{ISBN|0-19-513858-9}})
• Cysts on the left temporal lobe have been associated with psychosis.{{cite journal | author = Alves da Silva J, Alves A, Talina M, Carreiro S, Guimarães J, Xavier M | year = 2007 | title = Arachnoid cyst in a patient with psychosis: a case report | journal = Annals of General Psychiatry | volume = 6 | page = 16 | doi = 10.1186/1744-859x-6-16 | doi-access = free | pmid = 17598903 | pmc = 1933420 }}{{cite journal | author = Vakis AF, Koutentakis DI, Karabetsos DA, Kalostos GN | s2cid = 28934276 | year = 2006 | title = Psychosis-like syndrome associated with intermittent intracranial hypertension caused by a large arachnoid cyst of the left temporal lobe | journal = Br J Neurosurg | volume = 20 | issue = 3| pages = 156–9 | pmid = 16801049 | doi = 10.1080/02688690600776986 }} A left fronto-temporal cyst showed symptoms of alexithymia.{{cite journal | vauthors = Blackshaw S, Bowen RC | s2cid = 30229064 | title = A case of atypical psychosis associated with alexithymia and a left fronto-temporal lesion: possible correlations | journal = Can J Psychiatry | volume = 32 | issue = 8 | pages = 688–92 | date = November 1987 | pmid = 3690485 | doi = 10.1177/070674378703200809 }}
• Cyst on the right sylvian fissure resulted in new onset of schizophrenia-like symptoms at age 61.{{cite journal | vauthors = Cullum CM, Heaton RK, Harris MJ, Jeste DV | title = Neurobehavioral and neurodiagnostic aspects of late-onset psychosis | journal = Arch Clin Neuropsychol | volume = 9 | issue = 5 | pages = 371–82 | date = October 1994 | pmid = 14589653 | doi = 10.1093/arclin/9.5.371 }}
• A patient with a cyst on the left middle cranial fossa had auditory hallucinations, migraine-like headaches, and periodic paranoia
• Patients with left temporal lobe cysts had mood disturbances similar to manic depression (bipolar disorder) and were known to show outward aggressionHeinrichs, RW. In Search of Madness: Schizophrenia and Neuroscience Oxford University Press, USA (March 29, 2001); p129. ({{ISBN|0-19-512219-4}})

The exact cause of arachnoid cysts is not known. Researchers believe that most cases of arachnoid cysts are developmental malformations that arise from the unexplained splitting or tearing of the arachnoid membrane.{{citation needed|date=July 2021}}

In some cases, arachnoid cysts occurring in the middle fossa are accompanied by underdevelopment (hypoplasia) or compression of the temporal lobe. The exact role that temporal lobe abnormalities play in the development of middle fossa arachnoid cysts is unknown.{{citation needed|date=July 2021}}

There are some cases where hereditary disorders have been connected with arachnoid cysts.{{cite journal | vauthors = Schievink WI, Huston J, Torres VE, Marsh WR | title = Intracranial cysts in autosomal dominant polycystic kidney disease | journal = J. Neurosurg. | volume = 83 | issue = 6 | pages = 1004–7 | date = December 1995 | pmid = 7490613 | doi = 10.3171/jns.1995.83.6.1004 }}

Some complications of arachnoid cysts can occur when a cyst is damaged because of minor head trauma.{{cite journal | vauthors = De K, Berry K, Denniston S | title = Haemorrhage into an arachnoid cyst: a serious complication of minor head trauma | journal = Emerg Med J | volume = 19 | issue = 4 | pages = 365–6 | date = July 2002 | pmid = 12101165 | pmc = 1725893 | doi = 10.1136/emj.19.4.365 }} Trauma can cause the fluid within a cyst to leak into other areas (e.g., subarachnoid space). Blood vessels on the surface of a cyst may tear and bleed into the cyst (intracystic hemorrhage), increasing its size. If a blood vessel bleeds on the outside of a cyst, a collection of blood (hematoma) may result. In the cases of intracystic hemorrhage and hematoma, the individual may have symptoms of increased pressure within the cranium and signs of compression of nearby nerve (neural) tissue.{{citation needed|date=July 2021}}

Some scientists debate whether arachnoid cysts are a true congenital condition or if this should be separated from secondary cysts.{{cite book | vauthors = Westermaier T, Schweitzer T, Ernestus RI | chapter = Arachnoid Cysts | title = Neurodegenerative Diseases | volume = 724 | pages = 37–50 | date = 2012 | pmid = 22411232 | doi = 10.1007/978-1-4614-0653-2_3 | series = Advances in Experimental Medicine and Biology | isbn = 978-1-4614-0652-5 }} A recent study shows differences in communication between the arachnoid cyst and the subarachnoid space by CT cisternography.{{cite journal | vauthors = Wang X, Chen JX, You C, Jiang S | s2cid = 36127070 | title = CT cisternography in intracranial symptomatic arachnoid cysts: classification and treatment | journal = J. Neurol. Sci. | volume = 318 | issue = 1–2 | pages = 125–30 | date = July 2012 | pmid = 22520095 | doi = 10.1016/j.jns.2012.03.008 }} A comparison of arachnoid cyst fluid and CSF in a series of patients show differences in chemical composition.{{cite journal | vauthors = Berle M, Wester KG, Ulvik RJ, Kroksveen AC, Haaland OA, Amiry-Moghaddam M, Berven FS, Helland CA | title = Arachnoid cysts do not contain cerebrospinal fluid: A comparative chemical analysis of arachnoid cyst fluid and cerebrospinal fluid in adults | journal = Cerebrospinal Fluid Res | volume = 7 | pages = 8 | date = June 2010 | pmid = 20537169 | pmc = 2898803 | doi = 10.1186/1743-8454-7-8 | doi-access = free }}

Arachnoid cysts can also occur secondary to other disorders such as Marfan syndrome, arachnoiditis, or agenesis of the corpus callosum.{{citation needed|date=July 2021}}

File:Arachnoid cyst.png

File:Temporale Arachnoidalzyste links CT axial.jpg

Diagnosis is principally by MRI. Frequently, arachnoid cysts are incidental findings on MRI scans performed for other clinical reasons. In practice, diagnosis of symptomatic arachnoid cysts requires symptoms to be present, and many with the disorder never develop symptoms.{{citation needed|date=July 2021}}

Additional clinical assessment tools that can be useful in evaluating a patient with arachnoid cysts include the mini-mental state examination (MMSE), a brief questionnaire-based test used to assess cognition.

Arachnoid cysts can be found on the brain or on the spine. Intracranial arachnoid cysts usually occur adjacent to the arachnoidal cistern.Arachnoid cyst. (n.d.). Gale Encyclopedia of Neurological Disorders. Retrieved September 10, 2006, from Answers.com Web site: http://www.answers.com/topic/arachnoid-cyst Spinal arachnoid cysts may be extradural, intradural, or perineural and tend to present with signs and symptoms indicative of a radiculopathy.

Arachnoid cysts may also be classified as primary (congenital) or secondary (acquired) and have been reported in humans, cats, and dogs.{{cite journal | author = Reed SD, Cho DY, Paulsen D | year = 2009 | title = Quadrigeminal Arachnoid Cysts in a kitten and a dog | journal = J Vet Diagn Invest | volume = 21 | issue = 5| pages = 707–710 | doi = 10.1177/104063870902100519 | pmid = 19737770 | s2cid = 28289664 | doi-access = }}

Arachnoid cysts can be relatively asymptomatic or present with insidious symptoms; for this reason, diagnosis is often delayed.{{citation needed|date=July 2021}}

Most arachnoid cysts are asymptomatic and do not require treatment. Treatment may be necessary when symptomatic. A variety of procedures may be used to decompress (remove pressure from) the cyst.

• Surgical placement of a cerebral shunt:{{cite journal | vauthors = Strojnik T | s2cid = 45788859 | title = Different approaches to surgical treatment of arachnoid cysts | journal = Wien. Klin. Wochenschr. | volume = 118 | pages = 85–8 | date = 2006 | issue = Suppl 2 | pmid = 16817052 | doi = 10.1007/s00508-006-0540-2 }}
• An internal shunt drains into the subdural compartment.{{cite journal | vauthors = Helland CA, Wester K | title = Arachnoid cysts in adults: long-term follow-up of patients treated with internal shunts to the subdural compartment | journal = Surg Neurol | volume = 66 | issue = 1 | pages = 56–61; discussion 61 | date = July 2006 | pmid = 16793443 | doi = 10.1016/j.surneu.2005.12.032 }}
• A cystoperitoneal shunt drains to the peritoneal cavity.{{cite journal | vauthors = Park SW, Yoon SH, Cho KH, Shin YS | title = A large arachnoid cyst of the lateral ventricle extending from the supracerebellar cistern--case report | journal = Surg Neurol | volume = 65 | issue = 6 | pages = 611–4 | date = June 2006 | pmid = 16720186 | doi = 10.1016/j.surneu.2005.07.069 }}
• Fenestration:
• Craniotomy with excision{{cite journal | vauthors = Gangemi M, Colella G, Magro F, Maiuri F | s2cid = 46128402 | title = Suprasellar arachnoid cysts: endoscopy versus microsurgical cyst excision and shunting | journal = Br J Neurosurg | volume = 21 | issue = 3 | pages = 276–80 | date = June 2007 | pmid = 17612918 | doi = 10.1080/02688690701339197 }}
• Various endoscopic techniques are proving effective,{{cite journal | vauthors = Greenfield JP, Souweidane MM | title = Endoscopic management of intracranial cysts | journal = Neurosurg Focus | volume = 19 | issue = 6 | pages = E7 | date = December 2005 | pmid = 16398484 | doi = 10.3171/foc.2005.19.6.8 | s2cid = 24488862 | doi-access = }} including laser-assisted techniques.{{cite journal | vauthors = Van Beijnum J, Hanlo PW, Han KS, Ludo Van der Pol W, Verdaasdonk RM, Van Nieuwenhuizen O | s2cid = 35236043 | title = Navigated laser-assisted endoscopic fenestration of a suprasellar arachnoid cyst in a 2-year-old child with bobble-head doll syndrome. Case report | journal = J. Neurosurg. | volume = 104 | issue = 5 Suppl | pages = 348–51 | date = May 2006 | pmid = 16848093 | doi = 10.3171/ped.2006.104.5.348 }}
• Drainage by needle aspiration or burr hole.
• Capsular resection
• Pharmacological treatments may address specific symptoms such as seizures or pain.

Most arachnoid cysts are asymptomatic, and do not require treatment. Where complications are present, leaving arachnoid cysts untreated may cause permanent severe neurological damage due to the progressive expansion of the cyst(s) or hemorrhage (bleeding). However, with treatment most individuals with symptomatic arachnoid cysts do well.{{citation needed|date=July 2021}}

More specific prognoses are listed below:

• Patients with impaired preoperative cognition had postoperative improvement after surgical decompression of the cyst.{{cite journal | vauthors = Wester K, Hugdahl K | title = Arachnoid cysts of the left temporal fossa: impaired preoperative cognition and postoperative improvement | journal = J. Neurol. Neurosurg. Psychiatry | volume = 59 | issue = 3 | pages = 293–8 | date = September 1995 | pmid = 7673959 | pmc = 486033 | doi = 10.1136/jnnp.59.3.293 }}{{cite journal | vauthors = Wester K | s2cid = 792144 | title = Intracranial arachnoid cysts--do they impair mental functions? | journal = J. Neurol. | volume = 255 | issue = 8 | pages = 1113–20 | date = August 2008 | pmid = 18677648 | doi = 10.1007/s00415-008-0011-y }}
• Surgery can resolve psychiatric manifestations in selected cases.{{cite journal | vauthors = Kohn R, Lilly RB, Sokol MS, Malloy PF | title = Psychiatric presentations of intracranial cysts | journal = J Neuropsychiatry Clin Neurosci | volume = 1 | issue = 1 | pages = 60–6 | date = 1989 | pmid = 2577719 | doi = 10.1176/jnp.1.1.60 }}

Arachnoid cysts are seen in up to 1.1% of the populationFlaherty AW. The Massachusetts General Hospital Handbook of Neurology 2000 Jan 1;105. ({{ISBN|0-683-30576-X}}){{cite journal | vauthors = Vernooij MW, Ikram MA, Tanghe HL, Vincent AJ, Hofman A, Krestin GP, Niessen WJ, Breteler MM, van der Lugt A | title = Incidental findings on brain MRI in the general population | journal = N. Engl. J. Med. | volume = 357 | issue = 18 | pages = 1821–8 | date = November 2007 | pmid = 17978290 | doi = 10.1056/NEJMoa070972 | doi-access = free | hdl = 1765/35140 | hdl-access = free }} with a gender distribution of 2:1 male:female.{{cite journal | vauthors = Pradilla G, Jallo G | title = Arachnoid cysts: case series and review of the literature | journal = Neurosurg Focus | volume = 22 | issue = 2 | pages = E7 | date = February 2007 | pmid = 17608350 | doi = 10.3171/foc.2007.22.2.7 | doi-access = free }} Only 20% of these have symptoms, usually from secondary hydrocephalus.

A study that looked at 2,536 healthy young males found a prevalence of 1.7% (95% CI 1.2 to 2.3%). Only a small percentage of the detected abnormalities require urgent medical attention.{{cite journal | vauthors = Weber F, Knopf H | s2cid = 27917253 | title = Incidental findings in magnetic resonance imaging of the brains of healthy young men | journal = J. Neurol. Sci. | volume = 240 | issue = 1–2 | pages = 81–4 | date = January 2006 | pmid = 16256141 | doi = 10.1016/j.jns.2005.09.008 }}

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• Acoustic neuroma
• Arachnoiditis
• Brain tumor
• Dandy–Walker syndrome
• Empty sella syndrome
• Porencephaly
• Syringomyelia
• Hyperprolactinemia
• Panhypopituitarism
• Arnold–Chiari malformation
• Hydrocephalus

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{{Reflist}}

{{Medical resources

| DiseasesDB = 33219

| ICD10 = {{ICD10|G|93|0}}

| ICD9 = {{ICD9|348.0}}

| ICDO =

| OMIM = 207790

| MedlinePlus =

| eMedicineSubj = radio

| eMedicineTopic = 48

| MeshID = D016080

| SNOMED CT = 33595009

| Orphanet = 2356

}}

{{CNS diseases of the nervous system}}

{{Authority control}}

{{DEFAULTSORT:Arachnoid Cyst}}

Category:Congenital disorders

Category:Central nervous system disorders