Froin’s syndrome refers to CSF changes, which may

occur with subarachnoid block at or below the foramen

magnum—markedly increased total protein (often > 500

mg%), xanthochromia (owing to increased protein) and

spontaneous clotting.

Protein Electrophoresis of CSF

Proteins larger than 9S (sedimentation coefficient) do not

diffuse rapidly into the CSF, unless there is injury to the

blood-CSF barrier.

Monoclonal increase can be shown in some myeloma

cases. Multiple sclerosis causes increased IgG in CSF.

Besides multiple sclerosis, diffuse or discrete pathologic

gamma bands can be seen in:

¾ Subacute sclerosing leukoencephalitis

¾ Advanced neurosyphilis

¾ Primary lateral sclerosis

¾ Viral encephalitis

¾ Fungal meningitis

¾ Monoclonal gammopathy

¾ Myelopathy due to vitamin B12 deficiency.

Lange’s Colloidal Gold Test

Colloidal Gold Test

Though obsolete, it can be of great use if electrophoresis

cannot be done. It is an empirical way of evaluating CSF

protein fractions.

In the Lange’s method, progressive dilutions of CSF are

added to 10 test tubes containing colloidal gold solution

(Fig. 12.1). Precipitation causes the brilliant red colloidal

gold color (0) to change to:♥

Reddish blue (1+)

Purple (2+)

Deep blue (3+)

Pale blue (4+)

Colorless (5+)

The highest CSF concentration is reported on the

left with progressively decreasing concentrations to the

right. Normal fluids cause either no reaction or slight

precipitation in the middle dilutions, e.g. 0001210000.

A first zone curve is found in about 50% of patients

with multiple sclerosis as well as in general paresis of

insane. It may also be seen in encephalitis, postinfections,

encephalomyelopathy, sarcoidosis, hemorrhage, aseptic

meningeal reaction, polyneuritis, and meningeal carci -

noma. A typical series would be 5554210000 (Fig. 12.1).

A midzone curve or endzone curve is nonspecific and

may be found in any CSF with high protein content.

Glucose

Normally, CSF glucose is about 60–80% of corresponding

blood levels, or 50–80 mg%. Usually CSF glucose less than

40 mg% is considered decreased. Possible causes include:

¾ Systemic hypoglycemia

¾ Bacterial/tuberculous/fungal meningitis

¾ Meningeal carcinomatosis/leukemia infiltration

¾ Sarcoidosis involving CNS

¾ Subarachnoid hemorrhage

¾ Viral meningitis including mumps meningoencephalitis.

Conditions that Effect the CSF Glucose

No significant change.

Viral meningitis, neurosyphilis, brain or cord tumor,

cerebral thrombosis, multiple sclerosis, polyneuritis.

386 Concise Book of Medical Laboratory Technology: Methods and Interpretations Moderate reduction

CNS leukemia, meningeal carcinomatosis, subarachnoid

hemorrhage, partially treated bacterial or fungal meningitis

(CSF lactate will be high).

Marked reduction

Bacterial/tuberculous/fungal meningitis.

Enzymes

LDH

Lactate dehydrogenase is increased in CSF in:

¾ Bacterial

¾ Viral meningitis

¾ Subarachnoid hemorrhage

¾ Primary/secondary malignancy of brain/cord.

SGOT

Aspartate transferase (AT) is raised in CSF in:

¾ Primary/secondary malignancy of brain/cord

¾ Bacterial meningitis

¾ Intracerebral hemorrhage

¾ Subarachnoid hemorrhage.

CPK

Raised CSF-CPK (creatine phosphokinase) is found in:

¾ Brain infarct

¾ Multiple sclerosis

¾ Brain tumors

¾ Demyelinating disease, and

¾ Polyneuropathies.

Bacteriologic Examination

Smears and cultures for bacteria should be made of all

fluids when indicated.

1. Smears: Make smears directly if fluid is very turbid,