Differential Diagnosis for Lumbar Puncture Results

The provided lumbar puncture results can be analyzed to determine the likelihood of viral meningitis and other potential diagnoses. Here's a breakdown of the possible diagnoses based on the given cerebrospinal fluid (CSF) parameters:

• Single Most Likely Diagnosis

  • Viral meningitis: This is suggested by the opening pressure of 15 cm H2O, WBC count of 200/µL (with a predominance of lymphocytes, although not specified), glucose of 60 mg/dL, and protein of 95 mg/dL. These values are consistent with viral meningitis, which typically presents with a mild to moderate increase in WBC count, normal to slightly decreased glucose, and a mild increase in protein.

• Other Likely Diagnoses

  • Bacterial meningitis: The option with an opening pressure of 30 cm H2O, WBC count of 1,400/µL, glucose of 15 mg/dL, and protein of 300 mg/dL is highly suggestive of bacterial meningitis due to the significantly elevated WBC count, low glucose, and high protein levels.
  • Subarachnoid hemorrhage: The option with an opening pressure of 30 cm H2O, WBC count of 10/µL, glucose of 60 mg/dL, and protein of 300 mg/dL could suggest a subarachnoid hemorrhage, especially if the patient presents with sudden onset of severe headache. The elevated protein and normal glucose with few WBCs could be seen in the early stages of a hemorrhage before significant cellular response occurs.
  • Partially treated bacterial meningitis: The option with an opening pressure of 30 cm H2O, WBC count of 400/µL, glucose of 30 mg/dL, and protein of 300 mg/dL might represent partially treated bacterial meningitis, where antibiotic therapy has begun to reduce the bacterial load and the consequent inflammatory response, but the CSF parameters have not yet normalized.

• Do Not Miss Diagnoses

  • Cryptococcal meningitis: Especially in immunocompromised patients, this fungal infection can present with variable CSF findings, including elevated protein, low glucose, and a range of WBC counts. It's crucial to consider this diagnosis to initiate appropriate antifungal therapy.
  • Tuberculous meningitis: This condition can have a wide range of CSF abnormalities, including elevated protein, low glucose, and an increased WBC count with a lymphocytic predominance. Early diagnosis is critical due to the need for specific antitubercular therapy.

• Rare Diagnoses

  • Malignant meningitis: The spread of cancer to the meninges can result in elevated protein and variable glucose and WBC counts in the CSF. This diagnosis should be considered in patients with a known history of cancer.
  • Sarcoidosis: Neurosarcoidosis can involve the meninges, leading to increased protein and WBC count in the CSF. This diagnosis might be considered in patients with other systemic manifestations of sarcoidosis.
  • Lyme meningitis: Caused by Borrelia burgdorferi, this condition can present with lymphocytic pleocytosis, normal to slightly decreased glucose, and mildly elevated protein. It should be considered in patients with exposure history and appropriate clinical presentation.