Lumbar punctures (LP) have been used to diagnose diseases of the brain and spinal cord for more than 100 years. Today, lumbar punctures are allowing us to make key advances in understanding and treating Lewy body dementia. LPs are also routine, safe, and widely used.
What is a lumbar puncture?
Commonly known as a spinal tap, an LP is a short procedure during which a thin, hollow needle is carefully and gently inserted between the bones of the lower back. The needle is used to take a sample of cerebrospinal fluid. This clear fluid surrounds the brain and spinal cord and can reveal brain changes caused by diseases like Lewy body dementia.
The amount of cerebrospinal fluid used for LBD research is very small – only about one to two ounces. The brain makes about 12 ounces every day. After the LP, the brain replaces this small amount within hours.
Why is a lumbar puncture used for LBD research?
An LP provides a safe and effective way to collect a sample of cerebrospinal fluid and is done routinely for many diagnostic workups. By studying the fluid samples, researchers hope to answer important questions about LBD, including how to diagnose it earlier and more accurately. Cerebrospinal fluid samples may also help us learn how LBD develops.
In LBD research studies, samples are analyzed and if permission by the study participant is given, also stored for future studies. These ongoing clinical studies are critical for finding new LBD treatments, which is the top priority for LBD clinical research.
Is a lumbar puncture safe for those with LBD?
Lumbar punctures have been used safely for more than 100 years – it’s actually a very low-risk outpatient procedure performed by highly trained specialists.
Prior to the procedure, the doctor will review a person’s medical history and medications to assess potential risks. For people with LBD, there is no evidence that an LP increases confusion. In fact, there is no evidence of any unique risks to people with LBD who have an LP.
Does a lumbar puncture hurt?
A lumbar puncture is usually not painful, since a local anesthetic is applied to the injection spot before the LP begins. Most patients feel nothing except the slight sting of the local anesthetic needle.
Patients are asked to lie on their side with their knees drawn up, to help widen the spaces between the small bones in the spine, making it easier to insert the needle.
Once the needle is inserted, the patient may feel a bit of pressure. Some people feel a slight burning sensation or nerve twinges.
Is a lumbar puncture safe?
An LP has very minimal risks. In part, that’s because the needle is inserted in the lower spine where there is no spinal cord.
Like any procedure that uses a needle, an LP can cause infection or bleeding. But the risk is extremely rare for both. Before a lumbar puncture begins, the area on the back is cleaned and sterilized. Patients with a bleeding disorder or those taking blood thinners may be at an increased risk for bleeding.
Does a lumbar puncture have any side-effects?
A headache following the procedure rarely occurs in 10-15% of those who get an LP due to changes in CSF pressure.