(2)
Turbid spinal fluid:
Number of cells counted X dilution (10)
= cells per cu mm
volume (0.9 cu mm)
(3)
Very clouded spinal fluid:
Number of cells counted X dilution (20)
= cells per cu mm
volume (0.9 cu mm)
e. Source of Error. See paragraph 5-2e.
f. Discussion.
(1) If more than 100 leukocytes per cu mm are present, centrifuge the
undiluted specimen, make a smear, and stain with modified Wright's stain. Perform a
routine differential count and also estimate the ratio of erythrocytes to leukocytes.
NOTE:
It may be necessary to use egg albumin or cell-free serum to make the
sediment adhere to the slide.
(2) Normally the spinal fluid is water clear. It can be turbid if cell count is
500 or more cells per cu mm. If there is fresh blood with spontaneous clotting, the
indications are those of a bloody tap. Xanthochromia develops after subarachnoid
hemorrhage has been present for a few hours and is due to disintegration of blood
pigments. Xanthochromia may also develop from tumors, abscesses, and
inflammation.
(3) Cell counts above ten are considered to be evidence of intracranial
disease. The predominant cell in most viral infections, syphilis, and tuberculous
meningitis is the lymphocyte. Bacterial infections due to meningococcus,
pneumococcus, and so forth, usually result in a predominance of the neutrophil.
Cerebral and extradural abscesses as well as subdural hemorrhages produce a
neutrophilic response although bacteria are not demonstrated.
(4) Biochemical, bacteriological, virological, serological, and hematological
ands are all necessary to reflect the true condition of the cerebrospinal fluid. The
current laboratory standing operating procedures should give guidance for the most
efficient method to accomplish all the necessary ands.
g. Normal Value: Zero to five cells per cu mm (chiefly lymphocytes).
MD0853
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