The SAH's CSF!
Topic: Adult
Created on Friday, May 29 2009 by rednucleus
Last modified on Saturday, June 6 2009.
You think of subarachnoid hemorrhage in this 49-year-old man but his initial brain CT scan is unremarkable. One of your interns suggests doing lumbar puncture, as the best next step. All of the following statements about CSF findings in subarachnoid hemorrhage are correct, except:
A) The white cell count may be high B) The supernatant fluid following centrifugation becomes xanthochromic after 1-2 hours C) The opening pressure is usually very high D) The glucose level is normal initially E) The CSF is usually grossly bloody
This question was created on May 29, 2009 by rednucleus.
This question was last modified on June 06, 2009.
ANSWERS AND EXPLANATIONS
A) The white cell count may be high
This answer is incorrect.
The glucose level is normal initially.
The opening pressure is often very high and may exceed the upper limit of the standard CSF manometers, i.e. above 600 mm. The CSF is often grossly bloody and may be very difficult to differentiate it from traumatic taps in certain cases; it usually contains from 100 000 to more than 1 000 000 RBC/ mm3. The supernatant fluid following centrifugation becomes xanthochromic after 8-12 hours due to break down of RBCs and hemoglobin in situ. The white cell count may be high, but in the same proportion to red cells as in the peripheral blood. NB: Blood is highly irritating to the leptomeninges, and a "chemical" meningitis may be seen; the while cell count may be very high in the first 48 hours, and the glucose becomes low 4 to 8 days post ictus. In the absence of such a pleocytosis, the CSF glucose should be NORMAL. (
See References)
B) The supernatant fluid following centrifugation becomes xanthochromic after 1-2 hours
This answer is correct.
The glucose level is normal initially.
The opening pressure is often very high and may exceed the upper limit of the standard CSF manometers, i.e. above 600 mm. The CSF is often grossly bloody and may be very difficult to differentiate it from traumatic taps in certain cases; it usually contains from 100 000 to more than 1 000 000 RBC/ mm3. The supernatant fluid following centrifugation becomes xanthochromic after 8-12 hours due to break down of RBCs and hemoglobin in situ. The white cell count may be high, but in the same proportion to red cells as in the peripheral blood. NB: Blood is highly irritating to the leptomeninges, and a "chemical" meningitis may be seen; the while cell count may be very high in the first 48 hours, and the glucose becomes low 4 to 8 days post ictus. In the absence of such a pleocytosis, the CSF glucose should be NORMAL. (
See References)
C) The opening pressure is usually very high
This answer is incorrect.
The glucose level is normal initially.
The opening pressure is often very high and may exceed the upper limit of the standard CSF manometers, i.e. above 600 mm. The CSF is often grossly bloody and may be very difficult to differentiate it from traumatic taps in certain cases; it usually contains from 100 000 to more than 1 000 000 RBC/ mm3. The supernatant fluid following centrifugation becomes xanthochromic after 8-12 hours due to break down of RBCs and hemoglobin in situ. The white cell count may be high, but in the same proportion to red cells as in the peripheral blood. NB: Blood is highly irritating to the leptomeninges, and a "chemical" meningitis may be seen; the while cell count may be very high in the first 48 hours, and the glucose becomes low 4 to 8 days post ictus. In the absence of such a pleocytosis, the CSF glucose should be NORMAL. (
See References)
D) The glucose level is normal initially
This answer is incorrect.
The glucose level is normal initially.
The opening pressure is often very high and may exceed the upper limit of the standard CSF manometers, i.e. above 600 mm. The CSF is often grossly bloody and may be very difficult to differentiate it from traumatic taps in certain cases; it usually contains from 100 000 to more than 1 000 000 RBC/ mm3. The supernatant fluid following centrifugation becomes xanthochromic after 8-12 hours due to break down of RBCs and hemoglobin in situ. The white cell count may be high, but in the same proportion to red cells as in the peripheral blood. NB: Blood is highly irritating to the leptomeninges, and a "chemical" meningitis may be seen; the while cell count may be very high in the first 48 hours, and the glucose becomes low 4 to 8 days post ictus. In the absence of such a pleocytosis, the CSF glucose should be NORMAL. (
See References)
E) The CSF is usually grossly bloody
This answer is incorrect.
The glucose level is normal initially.
The opening pressure is often very high and may exceed the upper limit of the standard CSF manometers, i.e. above 600 mm. The CSF is often grossly bloody and may be very difficult to differentiate it from traumatic taps in certain cases; it usually contains from 100 000 to more than 1 000 000 RBC/ mm3. The supernatant fluid following centrifugation becomes xanthochromic after 8-12 hours due to break down of RBCs and hemoglobin in situ. The white cell count may be high, but in the same proportion to red cells as in the peripheral blood. NB: Blood is highly irritating to the leptomeninges, and a "chemical" meningitis may be seen; the while cell count may be very high in the first 48 hours, and the glucose becomes low 4 to 8 days post ictus. In the absence of such a pleocytosis, the CSF glucose should be NORMAL. (
See References)
References:
1. Victor, M., and Ropper, A.H. (2005). Adams and Victor's Principles of Neurology, 8th Edition. McGraw-Hill, New York. (ISBN:007141620X)
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2. Aminoff, M.A., Greenberg, D.A., Simon, R.P. (2005). Clinical Neurology, 6th Edition. McGraw-Hill, New York. (ISBN:0071423605) | Advertising:
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adult
The SAH's CSF!
Question ID: 052909089
Question written by rednucleus. (C) FrontalCortex.com 2006-2009, all rights reserved.
Created: 05/29/2009
Modified: 06/06/2009
Estimated Permutations: 120