A 48-year-old man comes to the emergency department due to 3 days of nausea and vomiting. For the past 4 weeks, the patient has also had increasingly severe headaches. He had a kidney transplant 2 years ago for glomerulonephritis and takes immunosuppressants. Temperature is 38.2 C (100.7 F), blood pressure is 140/90 mm Hg, and pulse is 70/min. The patient is awake but drowsy. Examination shows neck stiffness. Cranial nerves are intact. Muscle strength is normal, but deep tendon reflexes are brisk. CT scan of the head shows no other abnormalities. Results of cerebrospinal fluid analysis results are as follows: Which of the following is the most likely cause of this patient's symptoms?

Question

A 48-year-old man comes to the emergency department due to 3 days of nausea and vomiting.  For the past 4 weeks, the patient has also had increasingly severe headaches.  He had a kidney transplant 2 years ago for glomerulonephritis and takes immunosuppressants.  Temperature is 38.2 C (100.7 F), blood pressure is 140/90 mm Hg, and pulse is 70/min.  The patient is awake but drowsy.  Examination shows neck stiffness.  Cranial nerves are intact.  Muscle strength is normal, but deep tendon reflexes are brisk.  CT scan of the head shows no other abnormalities.  Results of cerebrospinal fluid analysis results are as follows:  Which of the following is the most likely cause of this patient's symptoms?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d144_3dbb_bc81_afd671a1601a_MD0003_00 This patient's progressive headache, vomiting, low-grade fever, and nuchal rigidity raises suspicion for meningitis. Most cases of meningitis are caused by common bacterial pathogens (eg, Streptococcus pneumoniae, Neisseria meningitidis). However, these organisms typically cause severe, life-threatening manifestations within hours or a few days of inoculation (Choice C). In this case, there are several features that suggest cryptococcal meningitis, including the following: Use of immunosuppressant medication: Cryptococcus neoformans is inhaled and subsequently forms a lifelong latent infection in the lung. Most patients remain asymptomatic, but those with severe immunocompromise (eg, AIDS, solid-organ transplantation, immunosuppressant medications) can develop reactivation with CNS spread. Subacute manifestations: Cryptococcus produces capsular proteins that clog cerebrospinal fluid outflow, leading to slowly progressive symptoms (eg, headache, vomiting, confusion) of elevated intracranial pressure. Characteristic lumbar puncture findings: Cryptococcal meningitis is marked by elevated opening pressure and cerebrospinal fluid evidence of lymphocytosis, mildly elevated white blood cell count, low glucose, and mildly elevated protein. Diagnostic confirmation requires identification of the encapsulated yeast in cerebrospinal fluid (eg, India ink stain) or on polysaccharide antigen testing. (Choice B) Herpes encephalitis occurs when herpes simplex type 1 moves in a retrograde fashion along the trigeminal nerve and attacks the temporal lobe. Patients usually have acute (<1 week) fever, confusion, seizure and/or neurologic deficits. Cerebrospinal fluid analysis typically shows significant red blood cells. This patient's normal CT scan of the head and long-standing symptoms make this diagnosis less likely. (Choice D) Patients with subarachnoid hemorrhage can have initial normal noncontrast head CT. However, cerebrospinal fluid analysis generally reveals significant red blood cells that do not decrease in quantity between tubes 1 and 4. In addition, patients generally have sudden-onset, severe headache, not one present for weeks. (Choice E) Toxoplasma encephalitis typically presents over weeks with headache, focal neurologic deficits, and/or seizure. CT scan of the head generally shows numerous ring-shaped lesions in the brain parenchyma. Most cases occur in patients with advanced AIDS. Educational objective: Patients with severe immunosuppression (eg, AIDS, solid-organ transplantation, immunosuppressant medications) are at increased risk for cryptococcal meningitis. Most cases are marked by subacute, progressive headache, vomiting, fever, and nuchal rigidity. Cerebrospinal fluid typically shows lymphocytosis with a mildly elevated white blood cell count, mild protein elevation, and low glucose.

A 48-Year-Old Man Comes to the Emergency Department Due to 3