Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Arachnoid cyst classification
Introduction
Overview
Overview
Arachnoid cysts may be classified according to cause into 2 subtypes/groups: primary or secondary, or according to symptoms into 3 groups.
Classification
Classification
Classification by cause
Arachnoid cysts can be classified by cause:
- Primary: developmental cysts, formed during the formation of arachnoid membranes in utero;
- Secondary: appear after trauma, infection, hemorrhage or surgery. Much less common.[1]
Classification by symptoms
They can also be further classified regarding the symptoms that they cause, as proposed by Choi et al.:
- First group: present with hydrocephalus and intracranial hypertension;
- Second group: present with dizziness, headaches, large head, seizures, strabismus, developmental delays and skull deformation;
- Third group: minimal or no symptoms.
This classification is closely related with prognosis. Patients from the first group had significant improvement after surgery, the third group had a much smaller benefit while patients from the second group had minimal benefit.[1]
Classification of spinal cysts
Nabors et al. suggested classifying arachnoid cysts of the spinal cord into three types:
- Type I – extradural cysts without nerve root involvement;
- Type II – extradural cysts with nerve root involvement;
- Type III – intradural cysts.[2]
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: José Eduardo Riceto Loyola Junior, M.D.[2]