Brain cysts are spheres filled with fluids such as water, cerebrospinal fluid, or tissue. Generally, brain cysts only become symptomatic, and thus problematic, when they have grown large. The main problem with brain cysts is the way they obstruct the flow of cerebrospinal fluid in the brain.
Colloid cysts are benign growths that account for 1 per cent of all brain tumours and do not generally result in symptoms. In rare cases when they do, the symptoms are caused by the obstruction of cerebrospinal fluid (CSF) in the foramen of Monro. Symptomatic patients experience chronic severe headaches. When the cyst becomes large enough to notably obstruct the flow of CSF, it can result in loss of consciousness, coma and death.
Because most cysts are asymptomatic, they are frequently found and diagnosed through either CAT scanning or an MRI. Once found, a problematic cyst can be treated through surgery.
Arachnoid cysts are found in the space between the arachnoid and pia mater layers of the meninges. They more commonly occur in infants and children than in adults, and in males more than females.
Like many other brain cysts, arachnoid cysts are asymptomatic until they have grown quite large. At that point, symptoms can include enlargement of the head, ADHD in children, hydrocephalus (build up of fluid in the brain) and dementia.
If an arachnoid cyst is found, the doctor will wait to see if it continues to grow. If it does, the usual course of treatment is to attempt to drain and remove the entire cyst. If the cyst blocks the flow of cerebrospinal fluid through the brain, a shunt might be used to help facilitate the movement of this fluid.
Dermoid cysts affect children younger than 10. They develop during early fetal growth and thus occur when cells destined for the face get trapped inside the brain. Dermoid cysts often contain hair follicles or skin cells that produce oils and fats. If a dermoid cyst opens, releasing this fluid into the brain, it results in chemical meningitis--an irritation of the meninges. Dermoid cysts do not cause symptoms until they are large enough to either burst or disrupt the flow of fluid in the brain, leading to headaches, sleepiness and impaired brain function.
They are extremely rare, and surgery is the course of treatment.
Epidermoid cysts develop in the same way as dermoid cysts. However, unlike dermoid cysts, they are usually found in middle-aged adults. Epidermoid cysts are benign but can cause the same symptoms of headache and impaired brain functions of other cysts if they grow large enough. They are removed through surgery.
Pineal cysts are usually discovered when a patient undergoes an MRI for an unrelated purpose. Symptoms can include headaches and difficulty looking upward. If a pineal cyst disrupts the flow of cerebrospinal fluid, and thus causes hydrocephalus, symptoms can also include sleepiness, trouble walking, double vision and confusion.