The document provides information on cerebrospinal fluid (CSF) examination including indications, collection, analysis, and findings in different conditions like meningitis. It discusses three clinical cases. For case 1, the diagnosis is bacterial meningitis based on cloudy CSF, low glucose, and high neutrophil count. Further tests would include cultures and sensitivity. For case 2, the diagnosis is viral meningitis (measles) based on clear CSF, normal glucose, and lymphocytic pleocytosis; complications include encephalitis. For case 3, the diagnosis is tuberculous meningitis based on low glucose, low chloride, and lymphocytic pleocytosis; confirmation requires microbiological tests.

1. PA35.3
IDENTIFY THE ETIOLOGY OF MENINGITIS
BASED ON GIVEN CSF PARAMETERS.
Dr IRA BHARADWAJ
MCI TEACHER ID
PAT 2300569

2. TEXTBOOK REFRENCES
• Henry’s clinical diagnosis and management by
laboratory methods: McPherson. Pincus
• Basics of body fluid analysis for UG&PG
students: Dr. Akhil Bansal

3. INTEGRATION
GENERAL MEDICINE
• IM17.7 enumerate the indications & describe
the findings in CSF in patients with meningitis
• IM17.9 interpret the CSF findings when
presented with various parameters of CSF
fluid analysis
DAVIDSON’S PRINCIPLES AND PRACTISE OF
MEDICINE: S H RALSTON, I D PENMAN, M W J
STRACHAN, R P HOBSON

4. INTEGRATION
PEDIATRICS
• GHAI ESSENTIAL PEDIATRICS: OP GHAI, VINOD K
PAUL, ARVIND BAGGA
MICROBIOLOGY
• MEDICAL LABORATORY MANUAL FOR TROPICAL
COUNTRIES BY MONICA CHEESEBROUGH
• TEXTBOOK OF MICROBIOLOGY DR C P BAVEJA

5. SPECIFIC LEARNING OBJECTIVES
• INTRODUCTION TO CSF
• COLLECTION OF CSF
• INDICATIONS FOR CSF EXAMINATION
• PHYSICAL EXAMINATION
• CHEMICAL EXAMINATION
• MICROSCOPIC EXAMINATION
• MICROBIAL EXAMINATION
• OTHER SPECIAL TESTS
• CSF IN HEALTH & MENINGITIS
• CASE DISCUSSION [THREE CASES]

6. INTRODUCTION TO CEREBROSPINAL
FLUID
• 70% of CSF is produced by choroid plexus in
the lateral, third and fourth ventricle, while
the remaining is produced by the surface of
the brain and spinal cord.
• CSF examination is an important part of
neurological evaluation in non- neoplastic and
neoplastic disease of CNS
• Total volume of CSF is approximately 150ml
• It is obtained by lumbar puncture (LP)

7. COLLECTION OF CSF
CSF is collected under aseptic conditions by
Lumbar Puncture with the aid of LP needle
Other techniques may be used in special
circumstances. They are :
• Cisternal Puncture
• Ventricular Cannulas or Shunts
• Lateral Cervical Puncture

8. COLLECTION OF CSF
Normally 2-3 ml of CSF is withdrawn for
examination, in three sterile tubes
• First tube is for biochemical tests
• Second tube for microbiological examination
• Third tube for cell count & cytology.
• A fourth tube may be used for viral titers &
other special tests when indicated

9. TRANSPORT & STORAGE OF CSF
• CSF should be sent to the respective labs as
quickly as possible
• It should be examined immediately
• Sample sent to microbiology lab should not be
refrigerated under any circumstances, as this will
inhibit growth of fastidious infective
microorganism like Neisseria
• In fact lab should be informed prior to sample
collection so they are ready to receive & process
the sample urgently

10. INDICATIONS FOR LUMBAR PUNCTURE
DIAGNOSTIC
HIGH SENSTIVITY & HIGH SPECIFCITY
Meningeal infections
• Pyogenic meningitis
• Tubercular meningitis
• Fungal

11. INDICATIONS FOR LUMBAR PUNCTURE
DIAGNOSTIC
HIGH SENSTIVITY, MODERATE SPECIFICITY
• Viral meningitis
• Subarachnoid hemorrhage
• Multiple sclerosis
• CNS syphilis
• Infectious polyneuritis
• Paraspinal abscess

12. INDICATIONS FOR LUMBAR PUNCTURE
DIAGNOSTIC
MODERATE SENSITIVITY & HIGH SPECIFICITY
• Meningeal malignancy
MODERATE SENSITIVITY & MODERATE
SPECIFICITY
• Intracranial hemorrhage
• Viral encephalitis
• Subdural hematoma

13. CONTRAINDICATIONS FOR LP
• Any patient with marked increase in CSF
• Any local infective lesion
• Coagulopathy

14. COMPLICATIONS OF LP
COMMON
• Headache
• CSF leak
• Back pain
RARE
• Trauma to nerves
• Extradural/subdural hematoma
• Introduction of infection
• Herniation of cerebellum through foramen
magnum

15. NORMAL COMPOSITION OF CSF
• Appearance Clear & Colorless
• Rate of Production 500 ml / day
• Total volume 120 – 150ml – adults
(10 – 60 ml in neonates)
• Sp. Gravity 1.006 – 1.008
• Normal pressure 60-150mm of water
in adults (10 -100 mm of water in infants)

16. NORMAL COMPOSITION OF CSF
• Sugar 50-80 mg /dl
• CSF- plasma sugar radio 0.3-0.9
• Proteins 15-45 mg/dl
• Chloride 650 – 760 mg/dl
• Cells 0-4 leucocytes /uL
(0-30 leucocytes /uL in neonates)
• Bacteria Nil

17. PHYSICAL EXAMINATION OF CSF
COLOR
• Normal – colorless
• Red – in first tube & clear in last tube – traumatic
tap
• All tubes having same red color – subarachnoid/
intracranial hemorrhage
• Yellow – increased bilirubin
• Pink/orange – blood breakdown products
• Green – infection/increased bilirubin

18. PHYSICAL EXAMINATION OF CSF
APPEARANCE
• Normal CSF is clear
• Cloudy – due to presence of leukocytes
• Turbid – due to presence of large number of
cells
COBWEB
• Cobweb coagulum forms on standing in cases
of tubercular meningitis

19. CHEMICAL EXAMINATION OF CSF
• Sugar, proteins, chloride are checked routinely
• Enzymes, ammonia and amines, electrolytes,
& other biochemicals like tumor markers may
be estimated in CSF, if indicated

20. CHEMICAL EXAMINATION OF CSF
CSF glucose
• Normal values are 50-80 mg/dl
Decreased
• Bacterial infection,
• Other inflammatory conditions,
• Hypoglycemia
Normal – viral infection
Increased – hyperglycemia

21. CHEMICAL EXAMINATION OF CSF
CSF proteins
• Normal values are 15-45 mg/dl
• Increased
IMPAIRED BLOOD-CSF BARRIER
• Inflammatory conditions eg meningitis
• Hemorrhage
CSF CIRCULATION DEFECTS
• Brain tumor
• Brain abscess

22. CHEMICAL EXAMINATION OF CSF
Chloride
• Normal levels are 650-750 mg/dl [ 118-
132mEq/L]
Decreased
• Bacterial meningitis - 600-700 mg/dl & in
• TB meningitis - below 600 mg/dl

23. MICROSCOPIC EXAMINATION OF CSF
Wet mount
• Examined for RBC, WBC, any other cells,
microorganisms
Total & Differential leukocyte count
• By Neubauer chamber & smear method
respectively
• Contains less than 5 mononuclear cells/uL
Cytology – if & when indicated eg tumors

24. MICROSCOPIC EXAMINATION OF CSF
Conditions causing neutrophilia (increase in
neutrophils)
• Bacterial/ Pyogenic meningitis
• Brain abscess
• Brain infarct
Conditions causing eosinophilia
• Parasitic infections
• Fungal infections
• Idiopathic

25. MICROSCOPIC EXAMINATION OF CSF
Conditions causing lymphocytosis (Increase in
lymphocytes)
• Viral meningitis
• Tuberculous meningitis
• Chronic meningitis
• Degenerative disorders
• Chronic lymphocytic leukemia
• Acute lymphocytic leukemia [with abnormal &
immature forms]

26. MICROSCOPIC EXAMINATION OF CSF
Conditions causing increase in plasma cells
• Tuberculous meningitis
• Syphilitic meningoencephalitis
• Multiple sclerosis
• Guillain- Barre syndrome

27. MICROSCOPIC EXAMINATION OF CSF
Conditions in which malignant cells are seen in
CSF
• Metastatic tumors
• Leukemia
• Lymphoma
• Medulla blastoma
• Ependymoma
• Spinal cord tumors

28. MICROBIOLOGICAL EXAMINATION OF
CSF
CSF can be stained with
• Gram’s Stain for bacteria
• Ziehl Neelsen Stain & others for TB
• India Ink for Cryptococcosis
CSF can be cultured to detect
• Bacteria
• Mycobacteria
• Fungus

29. SOME SPECIAL TESTS
• CRP is increased in acute infections
• Anti viral antibodies eg HIV, measles
• PCR for virus/ TB/fungus
• VDRL & other tests for syphilis
• Fungal serology eg aspergillus, histoplasma
• Cryptococcal antigen

30. CSF IN HEALTH & MENINGITIS
FEATURE NORMAL ACUTE PYOGENIC
(BACTERIAL)
ACUTE
LYMPHOCYTIC
(VIRAL)
CHRONIC (TB)
GROSS CLEAR &
COLOURLESS
CLOUDY OR
FRANKLY
PURULENT
CLEAR OR
SLIGHTLY TURBID
CLEAR OR
SLIGHTLY TURBID
FORMS COBWEB
COAGULUM ON
STANDING
CSF PRESSURE 60-150 mm OF
WATER
ELEVATED >180
mm OF WATER
ELEVATED >250
mm OF WATER
ELEVATED >300
mm OF WATER
CELLS
Per microliter
[uL]
0-4 LYMPHOCYTE 1000-1,00,000
NEUTROPHILS
10-100
LYMPHOCYTES
100-1000
LYMPHOCYTES
PROTEINS 15-45 mg /dL 50 - 200 mg/dL 50 - 150 mg/dL 50 - 150 mg/dL
GLUCOSE 50-80 mg/dL < 40 mg/dL) NORMAL LESS THAN 45
mg/dL
CHLORIDE
CONTENT
650 -760 mg/dl NORMAL OR
SLIGHTLY LOW
SLIGHTLY LOW LOW
< 600 mg/dl

31. CLINICAL CASE 1
A 5yr old male child brought to casualty with
complaints of fever, vomiting, headache &
irritability. On examination there is marked neck
rigidity, generalized hypertonia & photophobia.
LP performed, shows elevated CSF pressure
CSF findings are as follows:
Appearance – cloudy,
Proteins – 90 mg/dl,

32. CLINICAL CASE 1
Glucose – 30 mg/dl,
Chloride – 650mg/dl,
Cell count – 1200 cell/uL, mostly neutrophils.
Ans the following :
• What is your diagnosis
• Enumerate further investigations to confirm
your diagnosis

33. CLINICAL CASE 2
18 months child suffering from measles rushed
to casualty with seizures & loss of
consciousness.
LP performed shows elevated pressure & clear
CSF;
Other findings are as follows:
Protein – 80mg/dl ,
Glucose – 50mg/dl,

34. CLINICAL CASE 2
Chloride – 650mg/dl,
Cell count – 100 cells/uL, mostly lymphocytes.
Ans the following:
• What is your diagnosis
• How will you confirm the diagnosis
• Enumerate complications of measles

35. CLINICAL CASE 3
A 48 year old male presented with headache,
vomiting and confusion for about 3 weeks. LP
performed.
CSF findings are given:
• CSF pressure – 420 mm of water
• Appearance – slightly turbid
• Proteins – 66 mg/dl

36. CLINICAL CASE 3
• Glucose – 36 mg/dl
• Chloride – 580 mg/dl
• Microscopy – 530 cells / uL, mostly
lymphocytes
Answer the following:
• What is the most likely clinical diagnosis
• How will you confirm your diagnosis