Cerebrospinal Fluid Analysis

Am Fam Physician. 2021 Apr 1;103(7):422-428.

Abstract

Cerebrospinal fluid (CSF) analysis is a diagnostic tool for many conditions affecting the central nervous system. Urgent indications for lumbar puncture include suspected central nervous system infection or subarachnoid hemorrhage. CSF analysis is not necessarily diagnostic but can be useful in the evaluation of other neurologic conditions, such as spontaneous intracranial hypotension, idiopathic intracranial hypertension, multiple sclerosis, Guillain-Barré syndrome, and malignancy. Bacterial meningitis has a high mortality rate and characteristic effects on CSF white blood cell counts, CSF protein levels, and the CSF:serum glucose ratio. CSF culture can identify causative organisms and antibiotic sensitivities. Viral meningitis can present similarly to bacterial meningitis but usually has a low mortality rate. Adjunctive tests such as CSF lactate measurement, latex agglutination, and polymerase chain reaction testing can help differentiate between bacterial and viral causes of meningitis. Immunocompromised patients may have meningitis caused by tuberculosis, neurosyphilis, or fungal or parasitic infections. Subarachnoid hemorrhage has a high mortality rate, and rapid diagnosis is key to improve outcomes. Computed tomography of the head is nearly 100% sensitive for subarachnoid hemorrhage in the first six hours after symptom onset, but CSF analysis may be required if there is a delay in presentation or if imaging findings are equivocal. Xanthochromia and an elevated red blood cell count are characteristic CSF findings in patients with subarachnoid hemorrhage. Leptomeningeal carcinomatosis can mimic central nervous system infection. It has a poor prognosis, and large-volume CSF cytology is diagnostic.

Publication types

  • Review

MeSH terms

  • Central Nervous System Bacterial Infections / cerebrospinal fluid
  • Central Nervous System Bacterial Infections / diagnosis
  • Central Nervous System Fungal Infections / cerebrospinal fluid
  • Central Nervous System Fungal Infections / diagnosis
  • Central Nervous System Infections / cerebrospinal fluid*
  • Central Nervous System Infections / diagnosis
  • Central Nervous System Parasitic Infections / cerebrospinal fluid
  • Central Nervous System Parasitic Infections / diagnosis
  • Central Nervous System Viral Diseases / cerebrospinal fluid
  • Central Nervous System Viral Diseases / diagnosis
  • Cerebrospinal Fluid / chemistry
  • Cerebrospinal Fluid / cytology
  • Cerebrospinal Fluid / microbiology
  • Cerebrospinal Fluid Proteins / cerebrospinal fluid
  • Culture Techniques
  • Eosinophils
  • Glucose / cerebrospinal fluid
  • Humans
  • Leukocytes
  • Lymphocytes
  • Meningeal Carcinomatosis / cerebrospinal fluid*
  • Meningeal Carcinomatosis / diagnosis
  • Meningitis, Cryptococcal / cerebrospinal fluid
  • Meningitis, Cryptococcal / diagnosis
  • Neurosyphilis / cerebrospinal fluid
  • Neurosyphilis / diagnosis
  • Neutrophils
  • Polymerase Chain Reaction
  • Reference Values
  • Spinal Puncture
  • Subarachnoid Hemorrhage / cerebrospinal fluid*
  • Subarachnoid Hemorrhage / diagnosis
  • Tuberculosis, Central Nervous System / cerebrospinal fluid
  • Tuberculosis, Central Nervous System / diagnosis

Substances

  • Cerebrospinal Fluid Proteins
  • Glucose