What is a Berry Aneurysm?

The word aneurysm originally came from the Greek word aneurysma, which means a "widening." A berry aneurysm is the widening of an area of an artery inside the brain, making that part of the artery unusually thin and prone to rupture with pressure. An outpouching forms in the thin part of the artery, which looks like a saccule or a berry, hence the term saccular or berry aneurysm.

The majority of factors leading to the development of a cerebral berry aneurysm are still largely unknown. Hereditary genetic defects, however, have been linked to some patients with berry aneurysm. Some patients with this type of aneurysms have been found to also have other disorders, such as Marfan syndrome, Ehler's-Danlos syndrome (Type IV), and neurofibromatosis type-1.

Other factors that can increase an individual's risk for developing a cerebral berry aneurysm are old age, cigarette smoking, heavy alcohol intake, and drug abuse. Patients with a history of hypertension and atherosclerosis, or hardening of the arteries, as well as those with close relatives who suffered from a brain aneurysm are most often at higher risk to also develop a berry aneurysm. After menopause, women are also thought to have an increased risk because of lower levels of estrogen present in the body.

Saccular berry aneurysms are harmless most of the time. If they do not rupture, they rarely cause any serious health problems to affected people. Many people are unaware that they have the condition, and only become aware of its presence during medical evaluations for other health conditions. Patients generally do not have it upon birth, but develop the condition over time.

Ruptured berry aneurysms, however, can be life threatening. A rupture can lead to bleeding inside the brain, causing a type of stroke called subarachnoid hemorrhage (SAH). SAH mostly present with the sudden experience of a severe headache, described by many patients as the worst headache they have ever had. Other ruptured berry aneurysm symptoms include nausea, neck stiffness, blurry or double vision, confusion, and loss of consciousness.

Bleeding inside the brain can cause damage to brain cells. This can lead to hydrocephalus, or accumulation of fluid inside the brain, resulting in increased pressure inside the skull and greater injury to the brain tissues. Early treatment of a ruptured berry aneurysm is important to help prevent complications from setting in. Neurosurgeons and neurologists are the medical experts specializing in the treatment and management of these patients.