A 34-year-old Caucasian female presents to the emergency department (ED) with a 24-hour history of headaches, myalgias and low-grade fever. She grades the intensity of her headaches as 6-7 on a 10-grade scale, and states that she has never had such symptoms before. She does not know what could have brought these symptoms on. Nobody in her family, or among her co-workers, has recently had similar symptoms. She has no history of recent travel. Her past medical history is significant for an episode of severe pyelonephritis one year ago. CT scan of the head without contrast does not reveal any abnormality. A lumbar puncture is performed, and the CSF findings are as follows: CSF analyses on cryptococcal antigen, Lyme titer, bacterial stains, as well as bacterial cultures, are pending. Which of the following is most consistent with the CSF findings in this patient?

Question

A 34-year-old Caucasian female presents to the emergency department (ED) with a 24-hour history of headaches, myalgias and low-grade fever.  She grades the intensity of her headaches as 6-7 on a 10-grade scale, and states that she has never had such symptoms before.  She does not know what could have brought these symptoms on.  Nobody in her family, or among her co-workers, has recently had similar symptoms.  She has no history of recent travel.  Her past medical history is significant for an episode of severe pyelonephritis one year ago.  CT scan of the head without contrast does not reveal any abnormality.  A lumbar puncture is performed, and the CSF findings are as follows:  CSF analyses on cryptococcal antigen, Lyme titer, bacterial stains, as well as bacterial cultures, are pending.  Which of the following is most consistent with the CSF findings in this patient?

Quizplus · Accepted Answer

Explanation: The CSF findings in this patient are most consistent with traumatic lumbar puncture (LP), which results from accidental damage of a blood vessel during the procedure. A RBC count exceeding 6,000/mm3 may indicate traumatic LP, but other important causes, mainly subarachnoid hemorrhage (SAH), should be ruled out. WBC elevation in traumatic LP is commonly explained by the blood leak if approximately one WBC is present per 750-1000 RBCs. The protein level is elevated in the presence of traumatic LP, and the glucose level is typically high. (Choice C)Important findings that help to differentiate traumatic LP from SAH are xanthochromia and discoloration of centrifuged CSF due to hemoglobin breakdown. These are characteristic for SAH, and appear 2 to 4 hours after RBCs enter the subarachnoid space. These are present in more than 90% of patients within 12 hours of SAH. (Choices A, B and D)Interestingly, in one study, a WBC/RBC ratio not exceeding 0.01 has almost 100% negative predictive value for meningitis. Educational Objective: Traumatic lumbar puncture (LP) results from accidental damage of a blood vessel during the procedure. A high RBC count without xanthochromia is characteristic.

A 34-Year-Old Caucasian Female Presents to the Emergency Department (ED)