obsolete arachnoid cyst

Arachnoid Cyst: Obsolete Term

An arachnoid cyst, also referred to as an arachnoid cyst (disorder), is a type of extraparenchymal cyst that involves intra-arachnoidal collections of fluid. This condition is characterized by the accumulation of cerebrospinal fluid (CSF) within the potential space created by congenital splitting of the arachnoid layer.

Definition and Synonyms

• Definition: Not Available
• Synonyms:
  • Arachnoid cyst
  • Arachnoid cyst (disorder)
  • Leptomeningeal Cyst

Note that this term is considered obsolete, as indicated by the DOID:4445 reference.

Arachnoid Cysts: A Review of Obsolete Signs and Symptoms

Arachnoid cysts are fluid-filled sacs that develop on the brain or spinal cord, often causing a range of symptoms. While some sources may consider certain signs and symptoms as obsolete, it's essential to understand their historical context and relevance.

Historical Context In the past, arachnoid cysts were not always diagnosed promptly, leading to a delayed understanding of their associated symptoms. As medical knowledge advanced, so did our comprehension of these cysts' effects on the body.

Obsolete Signs and Symptoms

• Sleep Apnea: While sleep apnea is still considered a possible symptom of arachnoid cysts (see [1], [4]), it's not as commonly associated with these cysts as other symptoms.
• Tinnitus: Tinnitus, or ringing in the ears, was once thought to be a symptom of arachnoid cysts (see [1], [4]). However, its connection to these cysts is now considered less relevant.
• Hypoacusia: Hypoacusia, or decreased hearing, was also listed as a possible symptom (see [1], [4]). While it's still a concern in some cases, it's not as frequently associated with arachnoid cysts.

Current Understanding In contrast to these obsolete signs and symptoms, current medical understanding emphasizes the following:

• Headache: Headaches are a common symptom of arachnoid cysts, particularly when they're located around the brain (see [5], [11]).
• Nausea and Vomiting: Nausea and vomiting can also occur due to increased intracranial pressure or other factors related to the cyst (see [7], [13]).
• Hydrocephalus: Hydrocephalus, or fluid accumulation in the brain, is a possible symptom when arachnoid cysts are located around the brain (see [11]).

Conclusion While some signs and symptoms of arachnoid cysts may be considered obsolete, it's essential to understand their historical context. Current medical knowledge emphasizes headaches, nausea and vomiting, and hydrocephalus as more relevant symptoms associated with these cysts.

References:

[1] E Proimos (2014) - [1] [4] E Proimos (2014) - [4] [5] Small cysts are usually asymptomatic and found incidentally. - [5] [7] Increased intracranial pressure can cause symptoms such as headache, nausea, and vomiting. - [7] [11] Headache; Nausea and vomiting; Hydrocephalus (accumulation of fluid in the brain) - [11] [13] Arachnoid cysts around the spinal cord press parts of the spinal cord, or nerve roots, closer together. This causes symptoms such as back and leg pain and tingling or numbness in the legs or arms. - [13]

Based on the provided context, it appears that there are some outdated or less commonly used treatments for arachnoid cysts.

• Acetazolamide was mentioned as a safe and reasonable primary treatment option in pediatric patients with ruptured middle cranial fossa arachnoid cysts [3]. However, its use may be limited to specific cases.
• Atorvastatin has been described as a bold and safe choice in the management of subdural hematoma with mild symptoms, but its application to arachnoid cysts is unclear [6].

It's essential to note that these treatments might not be widely recommended or used today. The most recent information available suggests that surgery (craniotomy fenestration, endoscopic cyst fenestration, or shunt placement) and observation are more common approaches for treating arachnoid cysts [4][5].

If you're looking for information on the current treatment options for arachnoid cysts, I'd be happy to help. However, based on the provided context, it seems that these older treatments might not be as relevant or widely used today.

References: [3] Watson, I. (2022). Acetazolamide in pediatric patients with ruptured middle cranial fossa arachnoid cysts. [6] Liu, B. (2019). Atorvastatin in the management of subdural hematoma with mild symptoms.

Differential Diagnosis of Arachnoid Cysts

Arachnoid cysts are fluid-filled sacs that occur on the arachnoid membrane, which covers the brain and spinal cord. When diagnosing these cysts, it's essential to consider their differential diagnosis, which includes other types of cystic lesions in the central nervous system (CNS).

Main Differential Diagnoses

• Epidermoid Cysts: These are the most common diagnostic differentials for arachnoid cysts, especially those that develop in the posterior fossa. Epidermoid cysts can be differentiated from arachnoid cysts using MRI images [6].
• Porencephalic Cysts: These cysts communicate with the lateral ventricle and are another differential diagnosis to consider.
• Interhemispheric Cysts: These cysts, such as those associated with Dandy-Walker malformation or mega cisterna magna, can also be part of the differential diagnosis [7].
• Leptomeningeal Cysts: Post-traumatic leptomeningeal cysts and subdural hygroma are other conditions that may need to be ruled out in the differential diagnosis.

Imaging Techniques

MRI is a crucial tool for differentiating arachnoid cysts from other types of cystic lesions. Fluid-attenuated inversion recovery (FLAIR) images, diffusion-weighted images (DWIs), and phase-contrast cine MRI can help distinguish between these conditions [3][8].

Key Points to Consider

• Arachnoid cysts are fluid-filled sacs that occur on the arachnoid membrane.
• Epidermoid cysts are a common differential diagnosis, especially in the posterior fossa.
• Porencephalic cysts and interhemispheric cysts can also be part of the differential diagnosis.
• Imaging techniques like MRI, FLAIR images, DWIs, and phase-contrast cine MRI are essential for differentiating arachnoid cysts from other conditions.

References:

[1] Context 4 [2] Context 5 [3] Context 3 [6] Context 6 [7] Context 7 [8] Context 8