Cerebrospinal Fluid Puncture

A cerebrospinal fluid (CSF) puncture (LP) is the collection of cerebrospinal fluid (CSF for short; synonyms: Cerebrospinal fluid (CSF); cerebrospinal fluid, also called “neural fluid,” “cerebrospinal fluid,” or “brain water“). Puncture of the dural sac is usually performed in the region of the lumbar vertebrae (= lumbar puncture). It is performed primarily for the diagnosis of diseases of the central nervous system; if necessary, also for therapeutic reasons (e.g., to reduce the CSF volume or CSF pressure; intrathecal application of drugs). The cerebrospinal fluid (CSF) is a clear, colorless fluid containing only a few cells that surrounds the central nervous system in the subarachnoid space. The approximately 120-200 ml of CSF is formed by the choroid plexus (80%), cerebral parenchyma and ependymal cells of the ventricles and spinal canal (spinal cord canal) (20%) and circulates in the CSF space with constant production and reabsorption. Outflow occurs via the arachnoid villi. Approximately 500 ml of CSF is produced daily.

Indications

Cerebrospinal fluid puncture is performed in or suspected of:

  • Inflammation of the central nervous system (CNS).
  • Infectious diseases of the central nervous system (bacterial, viral, mycotic, parasitic infections) – e.g. meningitis (meningitis), encephalitis (brain inflammation).
  • CSF circulation disorders
  • Autoimmune diseases – e.g. multiple sclerosis (MS).
  • Diseases of the central nervous system with or without disease of the peripheral nervous system – e.g. Creutzfeld-Jakob disease, amyotrophic lateral sclerosis (ALS).
  • Neoplasia of the central nervous system – e.g. solid tumors, leukemia (blood cancer), lymphoma (collective term for lymph node enlargement or lymph node swelling and tumors of the lymphatic tissue).
  • Neurodegenerative diseases – e.g. Alzheimer’s disease.
  • CT-negative subarachnoid hemorrhage (SAB).
  • Trauma
  • Unclear disorders of consciousness
  • Idiopathic intracranial hypertension (IIH; pseudotumor cerebri) → CSF pressure measurementCaution: If there is a suspicion of increased intracranial pressure with risk of entrapment during lumbar pressure relief, this must be ruled out before performing the CSF puncture. Cranial CT (alternatively MRI) is the method of choice in this case.The detection of an absent papilledema (congestive papilla) by evaluating the fundus of the eye before performing the CSF puncture is of limited significance. Conversely, for example, the detection of papilledema in pseudotumor cerebri is not a contraindication for puncture.

Therapeutic indications

  • Reduction of CSF volume or pressure – for example, in pseudotumor cerebri (intracranial (“inside the skull“) pressure increase, in which no hydrocephalus (pathological expansion of the fluid spaces filled with cerebrospinal fluid (cerebral ventricles) of the brain) and no underlying intracranial space).
  • Application of drugs

Contraindications

  • Absolute contraindications
    • Intracranial pressure elevation
    • Midline shift below the falx cerebri (on CT).
    • Axial pressure increase with disappearance of suprachiasmal and circum-mesencephalic cisterns (on CT).
    • Thrombocytopenia: <20,000/μL
    • Superficial inflammation in the puncture area.
    • Deep inflammation of the subcutaneous tissue/musculature in the puncture area.
  • Relative contraindications
    • Coagulation disorders – thrombocytopenia < 50,000/μL
    • Anticoagulation – Marcumarized patients should be transitioned to heparin, as this can be antagonized more rapidly. Note: Puncture under acetylsalicylic acid is considered safe.

Before the cerebrospinal fluid puncture

  • Obtain medical history including medication history; if the patient is being treated with oral anticoagulants and/or dual antiplatelet therapy, see the current S1 guideline “Diagnostic CSF Puncture” for recommendations.
  • Magnetic resonance imaging (MRI) or computed tomography (CT) of the skull to exclude increased intracranial pressure (intracranial pressure) before the puncture [detection of existing indirect signs of intracranial pressure]Note: If bacterial meningitis is suspected, the lumbar puncture should be performed before imaging, as long as there are no clinical signs of increased intracranial pressure (e.g., intracranial pressure).B. Nausea, vomiting, or vigilance disorder/consciousness disorder in which sustained attention (vigilance) is impaired) exist.
  • If necessary, also ophthalmological examination (congestive papilla? ); not reliable in older age and acute intracranial pressure.
  • Determination of platelet count (small blood count) and coagulation.
  • Positioning of the patient:
    • Sitting position (= preferred positioning).
      • Advantages: Spine is straight in the vertical axis.
      • Disadvantages: CSF pressure measurement not possible
    • Side bearing
      • Advantages: possible in all patients (including debilitated patients, pregnant women); CSF pressure measurement possible.
      • Disadvantages: Hunchback position (“cat’s hump”) is sometimes more difficult to take.

The procedure

CSF puncture can be performed in the patient’s room in bed or in the outpatient clinic. Usual measures for disinfection and hygiene must be followed. Each puncture is performed under sterile conditions, which means disinfecting hands and skin surfaces, covering the area with a sterile drape, using sterile gloves and sterile disposable CSF puncture needles, and donning a mouth guard. Note: Atraumatic cannulas (e.g., Sprotte cannula) should be used for CSF punctures! Sterile gloves must be worn by the puncturer. Wearing of protective clothing and gloves by the assisting person. A face mask should be worn in the case of:

  • Presence of a respiratory infection in the puncturing person, the assisting person, or the patient.
  • Injection of fluids into the cerebrospinal fluid space, especially in immunocompromised patients
  • CSF puncture under training conditions (accompanied by explanations or instructions).
  • Performance of other diagnostic measures (e.g., CSF pressure measurement) with an increased time requirement

Several methods of CSF puncture are available for performing a CSF puncture.

  • Lumbar puncture (LP) – Lumbar puncture represents the most common form of CSF puncture. The puncture site is located between the spinous processes of the 3rd and 4th or 4th and 5th lumbar vertebrae and is determined using the line connecting the iliac crests. The optimal position of the patient is the fetal position. For this purpose, a seated position with maximum curvature of the back (with the support of a helper) is adopted. The use of a local anesthetic is possible, but not necessary. First, the puncture site is marked, followed by disinfection. The spinal needle is now inserted through the skin in an oblique direction directed cranially towards the navel. The needle is now advanced to the cerebrospinal fluid space, passing through the dura mater. To check the correct position of the spinal needle, aspiration is performed so that drops of cerebrospinal fluid emerge. If this is not the case, the position of the needle must be corrected. The CSF is collected in tubes and the needle is withdrawn again. The puncture site is finally covered with a sterile plaster and compressed for a few minutes.
  • Suboccipital puncture – This puncture is performed medially at the inferior border of the occiput. However, due to the complicated anatomical conditions, the risk of complications is very high, so this method is performed only in exceptional situations. Indications are:
    • When lumbar CSF cannot be obtained for an urgent indication or.
    • Pathologic-anatomic conditions (e.g., local abscess) are a contraindication to lumbar performance.
  • Lateral cervical puncture – This puncture is performed laterally between the 1st and 2nd cervical vertebrae. However, due to the complicated anatomical conditions, the risk of complications is very high, so this method is performed only in exceptional situations, when lumbar puncture is not possible.Generally considered a safe suboccipital access route, should also be performed under radiological control. This puncture should also be performed by physicians familiar with the method.
  • Ventricular puncture or ventricular catheter – Ventricular CSF can be obtained by puncturing the associated reservoir, initially discarding 1 ml.Indication:Ventricular puncture is performed as part of a surgical procedure. The main indications are therapeutic measures and follow-up examinations.

In combination with the CSF puncture, a CSF pressure measurement can be performed. This involves inserting a small riser tube that measures the pressure in millimeters of water column. Pressure measurement is performed when intracranial pressure elevation is suspected without evidence on imaging (e.g., computed tomography) or when hydrocephalus is suspected. At least 10 ml of CSF should be obtained during CSF puncture. CSF and serum samples collected at the same time should be sent immediately to a specialized laboratory.

After CSF puncture

  • To avoid complications, the patient should remain on his or her stomach for 1-2 hours and have a sandbag applied to the puncture site. Furthermore, the patient should be advised to drink plenty of fluids. The next 24 hours should be spent in bed in a horizontal position or in a head-down position.

Possible complications

  • Hemorrhage with spinal hematoma
  • Infections (spread of germs through puncture):
    • Local infection (rare side effect: <3%).
    • Epidural abscess
  • Circulatory reactions (rare side effect: <3%).
  • Syncope (disturbance of consciousness) (rare side effect: < 3%).
  • Nerve injury
  • Occurrence of inflammation of the spinal cord skin (very rare side effect).
  • Occurrence of subdural hematoma (very rare side effect).
  • Occurrence of bleeding into the spinal cord membranes (very rare side effect).
  • Cerebrospinal fluid hypotension syndrome/postpuncture syndrome (1-2 days after; may persist for a few days/rarely a few weeks) (common side effect: >3%):
    • Diffuse headache (post-puncture headache (PPKS; post-dural puncture headache (PDPH); post-lumbar puncture headache (PLPH)).
    • Neck stiffness
    • Tinnitus (ringing in the ears)
    • Hearing loss
    • Tendency to faint
    • Nausea (nausea)
    • Photophobia (photophobia)

    The risk of postpuncture headache increases with increasing needle diameter when conventional needles are used:

    • 16-19 G: over 70%
    • 20-22 G: 20-40 %
    • 24-27 G: 2-12 %
  • Other complications:
    • Persistent neurological symptomatology (visual disturbance; hearing loss).
    • Meningitis (meningitis)
    • Temporary failure of individual cranial nerves (very rare side effect).
    • In case of increased intracranial pressure: entrapment with disruption of circulation and respiration (very rare side effect) (possibly lethal).