Lumbar puncture, CSF analysis and interpretation

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Where is cerebrospinal fluid (CSF) produced?

In the arachnoid villi

In the choroid plexus of the ventricles (correct)

In the pineal gland

In the blood-brain barrier

Which of the following best describes the composition of cerebrospinal fluid (CSF)?

It is identical to extracellular fluid (ECF) in other parts of the body.

It has the same composition as blood plasma.

It is a specialized form of extracellular fluid (ECF) with different ionic concentrations. (correct)

It contains large amounts of proteins and red blood cells.

What is the primary function of cerebrospinal fluid (CSF)?

To provide nutrients to brain cells

To provide mechanical cushioning and support to the brain (correct)

To filter waste products from the brain

To regulate blood pressure in the brain

What is the normal volume of cerebrospinal fluid (CSF) in the human body?

125-150 ml Signup and view all the answers

What is a lumbar puncture commonly performed for?

To diagnose infections, hemorrhages, and other disorders affecting the central nervous system Signup and view all the answers

Which of the following is a diagnostic indication for a lumbar puncture (LP)?

Acute transverse myelitis Signup and view all the answers

Which of the following is a potential oncologic disorder that may require lumbar puncture (LP) for diagnosis?

Leptomeningeal metastases Signup and view all the answers

What is the main role of lumbar puncture (LP) in treating central nervous system (CNS) and leptomeningeal malignancies?

Intrathecal chemotherapy Signup and view all the answers

Which of the following conditions would not typically be treated using lumbar puncture (LP)?

Chronic hypertension Signup and view all the answers

Which of the following conditions can be diagnosed using lumbar puncture (LP) when CT scan results are normal?

Subarachnoid hemorrhage (SAH) Signup and view all the answers

Which of the following is an example of a metabolic disorder that might be evaluated using lumbar puncture (LP)?

Mitochondrial disorders Signup and view all the answers

Which of the following is a relative contraindication to performing a lumbar puncture (LP)?

Platelet count 20–40×10⁹/L Signup and view all the answers

Which of the following is an absolute contraindication for performing a lumbar puncture (LP)?

Anticoagulant therapy Signup and view all the answers

What is the absolute contraindication for performing a lumbar puncture (LP) in a patient with a platelet count of <20×10^9/L?

High risk of bleeding Signup and view all the answers

Which of the following conditions is considered an absolute contraindication for lumbar puncture (LP) due to the risk of herniation?

Non-communicating obstructive hydrocephalus Signup and view all the answers

Which of the following therapies is a relative contraindication for lumbar puncture (LP)?

Thienopyridines therapy Signup and view all the answers

In the case of a 60-year-old male with a history of coronary artery disease and recent myocardial infarction, with a platelet count of 25×10⁹/L on clopidogrel, is lumbar puncture (LP) safe?

No, LP is contraindicated due to thienopyridines therapy Signup and view all the answers

A 45-year-old woman with a history of stroke presents with a headache and signs of meningitis. Her platelet count is 35×10⁹/L. Should lumbar puncture (LP) be performed?

No, LP should be avoided due to the platelet count being below 40×10⁹/L Signup and view all the answers

In a case where a 55-year-old man presents with a sudden headache and signs of a possible subarachnoid hemorrhage, and a CT scan reveals non-communicating obstructive hydrocephalus, should lumbar puncture (LP) be performed?

No, LP is contraindicated due to the risk of brain herniation Signup and view all the answers

A 70-year-old female presents with acute confusion and suspected meningitis. She has a history of uncontrolled bleeding disorders and her INR is elevated at 3.5. Is lumbar puncture (LP) appropriate for this patient?

No, LP is contraindicated due to uncorrected bleeding diathesis Signup and view all the answers

In the case of a 50-year-old woman with a history of spinal stenosis and no signs of spinal cord compression, should a lumbar puncture (LP) be performed?

No, LP is contraindicated due to spinal stenosis Signup and view all the answers

Which of the following is NOT a risk factor that would warrant performing a CT brain prior to lumbar puncture (LP)?

History of hypertension Signup and view all the answers

A 50-year-old patient with a history of glioblastoma presents with fever and confusion. Should a CT brain be performed before lumbar puncture (LP)?

Yes, due to the patient's history of CNS disease Signup and view all the answers

A patient presents with a sudden headache, fever, and signs of meningitis. On examination, there is papilloedema. What should be done before performing a lumbar puncture (LP)?

Perform a CT brain immediately Signup and view all the answers

In a patient with new-onset seizures and signs of meningitis, why should a CT brain be performed before a lumbar puncture (LP)?

To assess for possible increased intracranial pressure (ICP) that may lead to herniation Signup and view all the answers

Which of the following CT brain findings would suggest a risk of raised intracranial pressure (ICP) in a patient before performing a lumbar puncture (LP)?

Sulcal effacement Signup and view all the answers

Which of the following is the most appropriate patient position for performing a lumbar puncture (LP)?

Lateral decubitus or fetal position Signup and view all the answers

In which anatomical location should the lumbar puncture needle be inserted for an adult patient?

Between the L3/L4 or L4/L5 interspace Signup and view all the answers

What is the correct positioning of the patient for a lumbar puncture (LP) in the lateral decubitus position?

The patient should lie on their side with the back arched and knees drawn to the chest. Signup and view all the answers

When performing a lumbar puncture (LP), why is it important to identify the L3/L4 or L4/L5 interspace?

To minimize the risk of injury to the spinal cord Signup and view all the answers

Why is it important to use aseptic technique during a lumbar puncture (LP)?

To prevent contamination of cerebrospinal fluid (CSF), which is normally sterile Signup and view all the answers

Which of the following is the correct way to prepare the overlying skin before performing a lumbar puncture (LP)?

Use chlorhexidine to disinfect the skin Signup and view all the answers

In the procedure for lumbar puncture (LP), the needle should be positioned:

In the midline with the bevel facing up Signup and view all the answers

After advancing the needle through the skin and encountering resistance at the spinous ligament, what is the next step in the lumbar puncture (LP) procedure?

Slowly advance the needle through the ligament Signup and view all the answers

Once the needle is in the subarachnoid space during a lumbar puncture (LP), what should be done next?

Remove the stylet from the needle Signup and view all the answers

When collecting cerebrospinal fluid (CSF) in sterile collection tubes during a lumbar puncture (LP), what is the correct method?

Allow the fluid to drip into the tubes, never aspirate Signup and view all the answers

If no cerebrospinal fluid (CSF) is obtained during a lumbar puncture (LP), what should be done?

Replace the stylet and advance the needle or adjust the angle Signup and view all the answers

Which of the following is true regarding the positioning of the needle during lumbar puncture (LP)?

The bevel of the needle should always face downward Signup and view all the answers

Which step in the lumbar puncture (LP) procedure is performed after the needle has entered the subarachnoid space? A) Advance the needle further to access the spinal cord B) Remove the stylet and wait for cerebrospinal fluid (CSF) to appear C) Apply pressure to the needle to prevent leakage D) Aspirate cerebrospinal fluid (CSF) to ensure proper needle placement

Remove the stylet and wait for cerebrospinal fluid (CSF) to appear Signup and view all the answers

During the lumbar puncture (LP) procedure, which of the following is the correct way to handle the collection tubes for CSF?

Ensure the tubes are sterile, and allow CSF to drip into them without aspiration Signup and view all the answers

Which of the following is the most common complication following a lumbar puncture (LP)?

Post-lumbar puncture headache Signup and view all the answers

A post-lumbar puncture headache typically presents with which of the following characteristics?

Classically frontal or occipital pain within 24-48 hours Signup and view all the answers

Which of the following is the most effective way to relieve a post-lumbar puncture headache?

Lying down Signup and view all the answers

Which of the following is a rare but serious complication of lumbar puncture (LP) that can occur in the presence of raised intracranial pressure (ICP)?

Cerebral herniation Signup and view all the answers

A patient develops a headache, neck stiffness, and nausea after lumbar puncture. The physician suspects infection. Which of the following is the most likely complication in this scenario?

Meningitis Signup and view all the answers

Which of the following is a common cause of post-lumbar puncture back pain?

Local irritation from the needle or positioning Signup and view all the answers

Which of the following is a relative contraindication for performing a lumbar puncture (LP)?

Local skin infection at the puncture site Signup and view all the answers

How should cerebrospinal fluid (CSF) specimens be transported to the microbiology laboratory?

In a tightly sealed leak-proof bag Signup and view all the answers

What is the most appropriate action when transporting cerebrospinal fluid (CSF) to the laboratory?

Hand deliver the specimen to the microbiology laboratory as soon as possible Signup and view all the answers

Which of the following is NOT a component typically analyzed in the CSF laboratory workup?

Electrolytes Signup and view all the answers

What additional tests may be conducted on cerebrospinal fluid (CSF) in the laboratory? (Select all that apply)

PCR for bacteria, viruses, or fungi Signup and view all the answers

Which of the following is a possible outcome in the CSF sample analysis that could indicate infection or inflammation?

Cloudy appearance with an elevated white blood cell count Signup and view all the answers

Which of the following is considered a normal protein level in cerebrospinal fluid (CSF) in an adult?

15-45 mg/dL Signup and view all the answers

What is the normal CSF glucose ratio in a healthy adult?

<blockquote> 0.6 </blockquote> Signup and view all the answers

Which of the following is considered an acceptable result for cerebrospinal fluid (CSF) obtained by lumbar puncture (LP)?

<5 white cells and <5 red cells Signup and view all the answers

Which of the following is NOT a typical analysis performed on cerebrospinal fluid (CSF) to detect possible infections?

Blood pressure monitoring Signup and view all the answers

Which of the following is the most important first step in the management of meningitis?

Ensuring airway and ventilation Signup and view all the answers

Which of the following is an appropriate empirical antibiotic regimen for suspected bacterial meningitis in old adult?

Ceftriaxone & vancomycin & amoxicillin Signup and view all the answers

Which of the following is a recommended adjunctive therapy in the management of bacterial meningitis?

Steroids (e.g., dexamethasone) before or with antibiotics Signup and view all the answers

When should a CT brain be performed prior to a lumbar puncture?

When there is papilloedema or focal neurological deficits Signup and view all the answers

Which of the following is an absolute contraindication for lumbar puncture?

Spinal stenosis or spinal cord compression above the level of the puncture Signup and view all the answers

What is the most likely pathogen in a patient with the following CSF findings? White cell count: 540/mm³ (90% polymorphs), Protein: 80 mg/dL, Glucose: CSF = 0.3 mmol/L, Serum = 5.7 mmol/L?

Bacterial Signup and view all the answers

What is the typical CSF profile for bacterial meningitis?

A) Elevated protein, normal glucose, raised lymphocytes B) Very elevated protein, low glucose, raised polymorphs C) Normal protein, normal glucose, raised lymphocytes D) Very low protein, normal glucose, raised polymorphs

Very elevated protein, low glucose, raised polymorphs Signup and view all the answers

What is the first-line empirical antibiotic therapy for suspected bacterial meningitis in old adults?

Ceftriaxone & Vancomycin & Amoxicillin Signup and view all the answers

Which of the following is a common feature of viral meningitis on CSF analysis?

Elevated protein, normal glucose, raised lymphocytes Signup and view all the answers

Which one of the following best describes this Gram stain of the CSF?

<60% blood glucose, elevated protein, cells raised (lymphocytes). A) Gram-negative bacilli B) Gram-negative diplococci C) Gram-positive cocci in chains D) Gram-positive diplococci

Gram-positive cocci in chains Signup and view all the answers

PCR performed on CSF reveals Streptococcus pneumoniae detected. What should be done now with the patient's antibiotic therapy?

Stop vancomycin and amoxicillin Signup and view all the answers

How long should the antibiotics be continued, and can they be given orally when stable?

14 days, intravenous antibiotics throughout Signup and view all the answers

Is antibiotic prophylaxis required for contacts of pneumococcal meningitis?

A) Yes, for all contacts B) No, prophylaxis is not indicated C) Yes, only for household contacts D) Yes, for healthcare workers only

No, prophylaxis is not indicated Signup and view all the answers

Should public health be notified in cases of pneumococcal meningitis?

Yes, invasive pneumococcal disease is notifiable Signup and view all the answers

What advice should be given to the patient regarding pneumococcal vaccination?

The patient should be offered the pneumococcal vaccine if unvaccinated or incompletely vaccinated Signup and view all the answers

The CSF results show a glucose level of less than 60% of the blood glucose, elevated protein, and raised cells (lymphocytes). Which form of meningitis does this suggest?

Tuberculous meningitis Signup and view all the answers

The CSF culture results show alpha-haemolysis on the optochin disk. Which organism is most likely responsible for this finding?

Streptococcus pneumoniae Signup and view all the answers

What is the most likely differential diagnosis for a 45-year-old female presenting with acute onset confusion, increasing drowsiness, and pyrexia, without focal neurological signs?

Encephalitis Signup and view all the answers

What is the key clinical sign in differentiating encephalitis from meningitis in this patient?

Acute confusion and drowsiness Signup and view all the answers

Which of the following is the most common cause of viral encephalitis?

Herpes Simplex Virus (HSV) Signup and view all the answers

What is a typical feature of HSV encephalitis on MRI brain?

Asymmetrical changes in the medial temporal lobes Signup and view all the answers

The CSF findings of an elevated white cell count (60 cells/mm³ with 98% lymphocytes), normal glucose levels (65 mg/dL), and mildly elevated protein (60 mg/dL) are suggestive on the lumbar puncture (LP) results. What is the likely diagnosis?

Viral encephalitis (HSV) Signup and view all the answers

What empiric therapy should be started for this patient with suspected HSV encephalitis?

Aciclovir 10 mg/kg TDS IV Signup and view all the answers

Given the diagnosis of HSV I DNA detected by PCR, what is the next step in the patient's anti-infective therapy?

Continue aciclovir intravenously Signup and view all the answers

How long should aciclovir therapy be continued for HSV encephalitis, and can it be switched to oral treatment once the patient is stable?

21 days, can switch to oral aciclovir once stable Signup and view all the answers

Should public health be notified in cases of HSV encephalitis?

Yes, HSV encephalitis is a notifiable disease Signup and view all the answers

Based on the history and the CSF results, what pathogen do you suspect in a patient with chronic headache, low-grade fever, weight loss, elevated protein, low glucose, cloudy appearance, and predominant lymphocytes?