1. The predictive value of both the positive leukocyte esterase test and
Pandy’s test in combination has been shown as 100%. The simultaneous
rise in CSF proteins and cells may not be seen in all the cases of
meningitis, though rise either in proteins or cells alone has been seen
more frequently. Even CSF can be normal in early meningitis.
2. Authors have admitted their limitations in diagnosis of tubercular
meningitis alone, though the same holds true for fungal meningitis,
where polymorphs are seen early and there is rise in CSF proteins(2).
3. It has not been mentioned for how many hours leukocyte esterase test,
remains positive in CSF samples after cell lysis, i.e. half life
of leukocyte esterase.
4. Age group in the study is from 1 month - 12 years. The neonatal CSF
protein values achieve childhood levels after 2 months of age(3). So
from 1 month to 2 completed months of age, Pandy’s test will be false
positive.
5. In the results, it
has been mentioned that two traumatic CSF samples with polymorphs were
leukocyte esterase positive whereas in Table 1, in cases with
traumatic CSF, the percentage of polymorphs is 0. In two samples of
viral meningitis, it has been mentioned in the text that there were 33
and 100 lymphocytes respectively, where in second sample, there were
only 6 lymphocytes/mm3 as shown in Table I.
Table I- Cerebrospinal Fluid Findings in Various Central Nervous
System Infections
Infection
|
Pressure
(mmH2O)
|
Leukocytes
Total(mm3)
|
PMN
(%)
|
Protein
(mg/dl)
|
Glucose
(mg/dl)
|
No infection (normal)
|
50-80
|
<5
|
<25
|
20-45
|
>50
|
Viral meningo-encephalitis
|
100-150
|
10-1000
|
<25
|
50-200
|
>50
|
Bacterial meningitis
|
100-300
|
100-10,000
|
>75
|
100-500
|
<40
|
Brain abscess
|
100-300
|
10-200
|
<25
|
75-500
|
>50
|
*May be predominance of PMNs in the first several hours of infection.
6. In the study,
polymorph >1 mm3 has been taken as a criteria for the diagnosis of
bacterial meningitis, whereas authors themselves have mentioned in the
text that presence of even one polymorph denotes meningitis.
7. The criteria used
for the diagnosis of bacterial meningitis do not match with those
mentioned in the original reference(4) (Table I).
8. The 31 cases shown
in Table I have been categorized in 4 categories, namely,
bacterial meningitis, partially treated bacterial meningitis, normal
CSF and traumatic CSF.
(i) Cases at
serial nos. 9, 29 and 30 have protein levels of 124, 86 and 60 mg/dl,
respectively. These cases have been mentioned as normal though
yardstick of protein > 40 mg/dl has been used for the diagnosis of
meningitis (bacterial/viral).
(ii) As per
criteria in original references, polymorphs >75% is used for
diagnosis of bacterial meningitis, whereas cases at serial nos. 3, 4,
14, 16, 18-21 and 25 with lymphocytic predominance have been labelled
as bacterial meningitis.
9. Reference 2 quoted
by the authors is not available in JAMA 1989; 262: 1121-1124, instead
some advertisement has been published on same pages.