A spinal tap or lumbar puncture is a procedure where a needle is inserted into the spinal canal for the collection of cerebrospinal fluid for diagnosis purposes. The most common reason for a spinal tap is for the diagnosis of diseases that involve the central nervous system. Examples of these diseases include meningitis, infection, medulloblastoma, and carcinomatous meningitis.
A spinal tap may also be used for therapeutic purposes in some conditions. One main contraindication of a spinal tap is increased intracranial pressure as it can result in further complications.
A spinal tap is usually performed under local anesthesia with a sterile technique. The patient is first placed on their side with their knees to the chest. The lower back is then prepared, palpated, and injected with local anesthesia. A hypodermic spinal needle is inserted between the third and fourth lumbar vertebrae or between the fourth and fifth lumbar vertebrae. It is pushed through the meninges, the protect layering around the spinal cord and brain, to the level of the subarachnoid space which contains the cerebral spinal fluid (CSF). A sample of CSF is then collected.
Side Effect #1: Postdural Puncture Headache
A postdural puncture headache is a common complication of a spinal tap. The headache is often described as severe, searing, and spreads “like hot metal,” involving both the back and front of the head. The headache may radiate to the shoulders and neck. Other associated symptoms include neck stiffness, hearing loss, nausea, tinnitus, vomiting, vertigo, paresthesia of the scalp, and dizziness.
It is a common side effect seen after lumbar puncture and spinal anesthesia. This is due to the leakage of cerebrospinal fluid leading to the reduced fluid levels in the spinal cord and brain.