Session 10 - Lecture 3: SAH or Meningitis

Question 1

What are the risk factors for SAH?

Answer 1

Trauma, hypertension, smoking, cocaine use, alcohol, aneurysm (90% berry), PKD, marfans and family history. .

Question 2

What is a berry aneurysm?

Answer 2

Absence of tunica media and lamina lead to rupture of blood vessels particularly at branch points of the circle of Willis (often congenital).

Question 3

What are the signs and symptoms of a SAH?

Answer 3

Often described as worst headache ever had (thunderclap), explosive, severe, diffuse, syncope, confusion, dizzy, neck stiffness, meningism, focal neurology and cardiac arrest.

Question 4

What investigations can be done for suspected SAH?

Answer 4

CT head, CT angiogram (if confirmed) and lumbar puncture.

Question 5

Describe the presentation of meningitis.

Answer 5

Fever, headache, nuchal rigidity, flu-like symptoms, stiffness, photophobia, seizure, non-blanching rash, altered mental state, shock, bulging fontanelle (babies).

Question 6

Describe the Kernig’s sign.

Answer 6

Patient lays flat on back, brings knees to chest and extends the knees, positive test will mean patient cannot do this due to nuchal rigidity, they will also have trouble flexing their neck –> sign of meningitis.

Question 7

What are the risk factors for meningitis?

Answer 7

CSF defects, spinal procedures, endocarditis, diabetes, alcohol, splenectomy and living in a crowded population.

Question 8

What investigations can be done for suspected meningitis?

Answer 8

FBCs and cultures, lumbar puncture (L4-L5, will feel give of ligamentum flavour and then dura), CT and CXR.

Question 9

Describe the opening pressure, appearance, protein levels, white cell count, glucose levels and red cell levels of a normal lumbar puncture.

Answer 9

Opening pressure = 8-18mmHg
Appearance = Clear
Protein levels = <45mg/L
White cell count = 0-5
Glucose levels = >60% of serum
Red cell levels = Minimal

Question 10

Describe the opening pressure, appearance, protein levels, white cell count, glucose levels and red cell levels of a lumbar puncture with meningitis of bacterial cause.

Answer 10

Opening pressure = 8-18mmHg
Appearance = Cloudy
Protein levels = <1g/L (high)
White cell count = 10-5000
Glucose levels = <1/2% of serum
Red cell levels = Minimal

Question 11

Describe the opening pressure, appearance, protein levels, white cell count, glucose levels and red cell levels of a lumbar puncture with meningitis of viral cause.

Answer 11

Opening pressure = 8-18mmHg
Appearance = Clear/cloudy
Protein levels = Normal/raised
White cell count = 15-1000 lymphocytes
Glucose levels = 60-80% of plasma
Red cell levels = Minimal

Question 12

Describe the opening pressure, appearance, protein levels, white cell count, glucose levels and red cell levels of a lumbar puncture with SAH.

Answer 12

Opening pressure = >18Hg
Appearance = Bloody/xanthochromia
Protein levels = >1g/L
White cell count = 0-5
Glucose levels = >60% of serum
Red cell levels = >500,000

Question 13

What does a xanthochromia appearance signify?

Answer 13

Yellow coloured appearance

Red cells–>oxyhemoglobin (haemolysis) –> bilirubin (haemorrhage oxidase).

Question 14

Why are multiple samples required when performing a lumbar puncture?

Answer 14

If blood in all samples, indicative of SAH

If blood is present only in the first sample, this is indicative of a traumatic tap.

Question 15

What is the treatment for SAH?

Answer 15

Decompression, coiling/clipping aneurysm, neuro obs, IV fluids (3L/day), nimodipine (CCB) –> reduces vasospasm and vasoconstriction.

Question 16

What is the treatment for meningitis?

Answer 16

Analgesic, antipyretics, IV fluids, IV ceftriaxone and dexamethasone.