A brain biopsy is the surgical removal of a small piece of the brain tissue to diagnose diseases and conditions of the brain. It is typically used to diagnose Alzheimer’s disease, tumors, inflammation, and infection. Brain diseases can be very debilitating, and diagnosing the underlying condition is the first step in determining treatment options.
Physicians order brain biopsies when — based on other signs — they suspect a patient may have a disease of the brain. Symptoms vary depending on the condition, but may include memory loss, confusion, muscle twitches, and extreme headaches or dizziness. Imaging scans are usually done prior to performing a brain biopsy, both to further support the suspected diagnosis and to guide the surgeon to the proper location for the biopsy.
Surgeons typically use one of three methods when performing a brain biopsy. During a burr hole biopsy, a small hole is made in the skull over the area where the tissue sample will be removed. In a craniotomy, surgeons cut and remove a small portion of the skull to reach the tissue, and then replace the skull fragment after the biopsy is taken. A stereotactic brain biopsy uses a computer to guide the surgeon to the tissue sample; this is usually the preferred method, because it only requires a tiny hole.
On the day of the procedure, patients receive either local or general anesthesia, depending on the area of the brain biopsy. The area of the head near the biopsy site is shaved and cleansed with an antiseptic. Immediately after the biopsy, patients are taken to a recovery room until the anesthesia wears off and they are stable enough to return home. Some patients may be required to stay in the hospital for up to two days or longer if complications arise during or after the biopsy.
After the removal of a tissue sample, a pathologist analyzes the brain biopsy under a microscope for abnormalities. For example, a patient with Alzeheimer’s disease usually exhibits abnormal collections of plaque in the cortex of the brain. If a brain infection is suspected, the pathologist will take a sample of the infectious organism and identify it to determine the best course of treatment. Brain tumors can also be classified through a brain biopsy.
A brain biopsy is an invasive procedure and carries risks. Any time anesthesia is used, there is potential for an adverse reaction. Brain injury is also a possibility, which can lead to various symptoms depending on the area of the brain affected. The scar tissue that forms on the brain because of the procedure can trigger seizures. Infection at the site of the cut can also occur without proper wound care after the procedure. Careful supervision after the procedure can help minimize the effects of these side effects.