Critical Care Medicine-Neurologic Disorders>>>>>Inflammatory and Demyelinating
Question 1#

A 21-year-old male presents to the emergency department with a history of fevers to 100.4°F, headache, nausea, and vomiting for the last 48 hours. He has a history of tonic-clonic seizures for which he takes phenytoin. He has recently started taking ibuprofen for his headaches. He has no allergies. He has not had his flu shot this year, and no one else is unwell in his family. On examination, he is lying down in a dark room and requests for you to avoid turning on the light. He is somnolent but has no focal weakness. He is unable to flex his neck without discomfort.

The emergency room physician had empirically started ceftriaxone and vancomycin and performed a lumbar puncture with the following results:

CSF = cerebrospinal fluid

What is the MOST LIKELY cause of his symptoms?

a. Bacterial meningitis
b. Recent seizure
c. Herpes simplex virus meningitis
d. Ibuprofen

Correct Answer is C

Comment:

Correct Answer: C

Aseptic meningitis refers to the patient population that have negative CSF gram stain and cultures but laboratory and clinical evidence of meningeal irritation. The most common causes are the enteroviruses such as coxsackie virus and echovirus. Additional etiologies form a fairly extensive list which includes other infections (mycobacteria, fungi, spirochetes), parameningeal infections (HIV, herpes simplex, varicella zoster, Epstein-Barr virus, cytomegalovirus, human herpes virus-6, and adenoviruses), medications (ibuprofen), and malignancies (lymphoma). CSF from bacterial meningitis would have positive gram stains, greatly elevated WBCs >150 cells/mm3 , high protein, and reduced glucose levels. Seizures may be associated with CSF pleocytosis and transiently elevated CSF protein levels, however, the clinical presentation does not fit this. Drug-induced aseptic meningitis is primarily a diagnosis of exclusion and unlikely to have elevated WBCs and RBCs. A fungal infection would be a very rare cause of aseptic meningitis in an immunocompetent individual; however, HIV testing would likely be warranted in this diagnostic workup. 

References:

  1. Connolly KJ, Hammer SM. The acute aseptic meningitis syndrome. Infect Dis Clin North Am. 1990;4(4):599.
  2. Jarrin I, Sellier P, Lopes A, et al. Etiologies and management of aseptic meningitis in patients admitted to an internal medicine department. Medicine. 2016;95:e2372.
  3. Chatzikonstantinou A, Ebert AD, Hennerici MG. Cerebrospinal fluid findings after epileptic seizures. Epileptic Disord. 2015;17(4):453-459.
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