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64-Year-Old Man With Subacute Altered Mental Status and Headache

Published:February 12, 2019DOI:https://doi.org/10.1016/j.mayocp.2018.05.040
      A 64-year-old man from Iowa with a medical history of sarcoidosis, managed with prednisone, 20 mg/d, for the past 5 months, presented to the emergency department with gradual-onset, progressive altered mental status and headaches of 1 month’s duration. Previously, he was cognitively intact according to his daughter. He had become unable to perform normal daily tasks such as unlocking doors and holding normal conversations. Additionally, he reported a generalized, throbbing, constant headache associated with intermittent blurry vision. About 1 week before presentation, he also experienced severe fatigue and lethargy in addition to a few falls. He had no fever, weight loss, syncope, seizures, or neck stiffness, no exposure to birds or their droppings, no history of travel to the American Southwest or elsewhere, and no sick contacts.
      On presentation, his vital signs revealed a temperature of 36.6°C; blood pressure, 148/103 mm Hg; heart rate, 104 beats/min; and oxygen saturation, 98% while breathing room air. He appeared intermittently confused but had no meningismus, papilledema, or focal neurologic deficits on physical examination.
      Initial laboratory evaluation revealed the following (reference ranges provided parenthetically): hemoglobin, 16.8 g/dL (13.2-16.6 g/dL); leukocytes, 10.2 × 109/L (3.4-9.6 × 109/L); platelets, 261 × 109/L (135-317 × 109/L); electrolytes within normal limits; thyrotropin, 1.8 mIU/L (0.3-4.2 mIU/L); and prothrombin time, 13.3 seconds (9.4-12.5 seconds). Urinalysis results were normal. Acetaminophen and salicylate levels were undetectable. Computed tomography of the head revealed no bleeding, masses, or other changes that would explain the clinical picture.
      • 1. Based on this patient’s presentation, which one of the following diagnostic tests should be performed next?
        • a.
          Magnetic resonance imaging (MRI) of the brain
        • b.
          Electroencephalography
        • c.
          Lumbar puncture (LP)
        • d.
          Angiotensin-converting enzyme measurement
        • e.
          Electromyography
      Magnetic resonance imaging of the brain is a good test to evaluate changes within the brain parenchyma and can also help in the diagnosis of herpes simplex virus (HSV) encephalitis. However, it is expensive, time consuming, and not readily available in all practice settings. The criterion standard for diagnosis of HSV encephalitis is the detection of HSV DNA in the cerebrospinal fluid (CSF) by polymerase chain reaction (PCR). Although brain MRI might be needed later on, it is not the best next step in this patient’s situation. Electroencephalography could help evaluate for seizure activity or epilepsy, but the patient has no history suggestive of such disorders at this presentation. The best diagnostic step in evaluating a patient, especially if immunocompromised, with subacute altered mental status, headaches, and no focal neurologic deficit is LP. Meningitis and encephalitis must be high on the differential diagnosis and would require CSF analysis for diagnosis. Lumbar puncture can be performed easily by many physicians in different practice settings, has a low complication risk, and is less expensive than MRI. The differential diagnosis may include neurosarcoidosis as well, but it usually presents with cranial nerve palsies and less commonly with headaches.
      • Zajicek J.P.
      • Scolding N.J.
      • Foster O.
      • et al.
      Central nervous system sarcoidosis—diagnosis and management.
      Furthermore, angiotensin-converting enzyme levels have low sensitivity and specificity in diagnosing sarcoidosis.
      • Ungprasert P.
      • Carmona E.M.
      • Crowson C.S.
      • Matteson E.L.
      Diagnostic utility of angiotensin-converting enzyme in sarcoidosis: a population-based study.
      Electromyography may be useful for evaluating proximal muscle weakness or the presence of peripheral neuropathy, which are absent in this patient.
      Lumbar puncture yielded clear CSF. Initial CSF analysis revealed the following (reference ranges provided parenthetically): opening pressure, 25 cm H2O (7-18 cm H2O); total protein, 107 mg/dL (0-35 mg/dL); glucose, 35 mg/dL, with a serum glucose level of 102 mg/dL (CSF glucose should be 60% of serum glucose when drawn concurrently); total nucleated cells, 34/μL (0-5/μL); erythrocytes, 0% (0%); neutrophils, 3% (0%-6%); lymphocytes, 69% (40%-80%); and monocytes, 28% (15%-45%).
      • 2.
        Given the overall presentation so far, which one of the following additional CSF tests would provide the highest diagnostic yield?
        • a.
          Streptococcus pneumoniae PCR
        • b.
          Neisseria meningitidis PCR
        • c.
          Enterovirus PCR
        • d.
          Coccidioidomycosis antigen test
        • e.
          Cryptococcal antigen test
      Streptococcus pneumoniae and N meningitides are common pathogens in acute bacterial meningitis, which presents with fever, nuchal rigidity, and characteristic CSF findings of pleocytosis (cell count over 100), low glucose level, and high protein value.
      • Durand M.L.
      • Calderwood S.B.
      • Weber D.J.
      • et al.
      Acute bacterial meningitis in adults: a review of 493 episodes.
      This scenario does not fit with our patient’s subacute/chronic disease course nor with results of his CSF analysis. Enterovirus causes aseptic meningitis, characterized by a rapid onset (within hours) as opposed to the month-long course our patient experienced. Additionally, the cost and lack of actionable treatment, combined with generally good outcomes, makes the clinical utility of enterovirus PCR low in many cases.
      • Bahr N.C.
      • Boulware D.R.
      Methods of rapid diagnosis for the etiology of meningitis in adults.
      Coccidioidal meningitis can present with subacute headache and mental status changes, but it is primarily found in the southwestern United States. Our patient is from Iowa and had no recent travel. Cryptococcal antigen testing would provide the highest diagnostic yield in this patient. First, his clinical course is consistent with subacute meningoencephalitis, characterized by a subacute headache and gradual mental status changes over 2 to 4 weeks, which is seen with cryptococcal meningitis (CM).
      • Pappas P.G.
      • Perfect J.R.
      • Cloud G.A.
      • et al.
      Cryptococcosis in human immunodeficiency virus-negative patients in the era of effective azole therapy.
      Second, his initial CSF findings of mildly elevated nucleated cell count with a lymphocyte predominance, low glucose concentration, and high protein level are suggestive of a fungal or mycobacterial infection, the latter being less common. When CM is suspected, sending the CSF for cryptococcal antigen testing is the appropriate next step. It can be analyzed quickly and has a sensitivity of 93% to 100% and a specificity of 93% to 98%.
      • Tanner D.C.
      • Weinstein M.P.
      • Fedorciw B.
      • Joho K.L.
      • Thorpe J.J.
      • Reller L.
      Comparison of commercial kits for detection of cryptococcal antigen.
      • Abassi M.
      • Boulware D.R.
      • Rhein J.
      Cryptococcal meningitis: diagnosis and management update.
      Our patient was admitted to the hospital. His CSF studies were positive for cryptococcal antigen, with a high titer of greater than 1:2560. Cerebrospinal fluid cultures grew Cryptococcus neoformans after 25 days of inoculation. Results of human immunodeficiency virus (HIV) serology and CSF mycobacterial cultures were negative. With a confirmed diagnosis of CM, input from the infectious disease department was sought to provide recommendations for treatment.
      • 3.
        Which one of the following is the preferred induction therapy for CM in this patient?
        • a.
          Flucytosine for at least 2 weeks
        • b.
          Liposomal amphotericin B for at least 2 weeks
        • c.
          Fluconazole for at least 2 weeks
        • d.
          Liposomal amphotericin B and flucytosine for at least 2 weeks
        • e.
          Liposomal amphotericin B and fluconazole for at least 2 weeks
      A quick and effective reduction of the yeast burden within the central nervous system (CNS) is the goal of induction therapy. Each one of the first 3 medications—flucytosine, liposomal amphotericin B, and fluconazole—may be active in vitro against cryptococcosis, but monotherapy with any one of them is not recommended given the better and faster fungicidal activity of combination therapy. For patients with CM who are HIV negative and have not had a transplant, the current clinical practice guidelines recommend induction therapy with amphotericin B deoxycholate (0.7-1.0 mg/kg per day intravenously [IV]) and flucytosine (100 mg/kg per day orally in 4 divided doses).
      • Perfect J.R.
      • Dismukes W.E.
      • Dromer F.
      • et al.
      Clinical practice guidelines for the management of cryptococcal disease: 2010 update by the Infectious Diseases Society of America.
      This combination is associated with improved survival compared with amphotericin B monotherapy. No survival benefit of amphotericin B plus fluconazole was found in a recent randomized trial.
      • Day J.N.
      • Chau T.T.H.
      • Wolbers M.
      • et al.
      Combination antifungal therapy for cryptococcal meningitis.
      Given the higher toxicity with amphotericin B deoxycholate, lipid formulations including liposomal amphotericin B (3-4 mg/kg per day IV) and amphotericin B lipid complex (5 mg/kg per day IV) are often substituted for amphotericin B deoxycholate in the United States. Induction therapy is recommended for at least 4 weeks if there are no neurologic complications. In patients who are at low risk for therapeutic failure, induction therapy can be shortened to only 2 weeks. Such patients include those who have an early diagnosis by history, no uncontrolled underlying disease or immunocompromised state, and excellent clinical response to initial 2-week induction therapy. Conversely, in patients who do exhibit focal neurologic complications, induction therapy can be extended to 6 weeks. Following induction therapy, consolidation therapy with fluconazole (800 mg/d orally) should be given for 8 weeks. After induction and consolidation therapy, patients should receive maintenance therapy with fluconazole (200 mg/d orally) for 6 to 12 months.
      • Perfect J.R.
      • Dismukes W.E.
      • Dromer F.
      • et al.
      Clinical practice guidelines for the management of cryptococcal disease: 2010 update by the Infectious Diseases Society of America.
      Liposomal amphotericin B and flucytosine were administered, but the patient continued to have morning headaches a few days later.
      • 4.
        Which one of the following is the preferred first step in the management of this patient’s morning headaches?
        • a.
          Acetazolamide
        • b.
          Mannitol
        • c.
          Corticosteroids
        • d.
          Serial LPs
        • e.
          Ventriculoperitoneal shunt
      Our patient has an elevated intracranial pressure (ICP), supported by an opening pressure of 25 cm H2O during his LP. This common complication of CM is responsible for his morning headaches. Acetazolamide, mannitol, and corticosteroids have no proven benefit in this setting, so they are not recommended.
      • Perfect J.R.
      • Dismukes W.E.
      • Dromer F.
      • et al.
      Clinical practice guidelines for the management of cryptococcal disease: 2010 update by the Infectious Diseases Society of America.
      The preferred first step in management is serial LPs to reduce his opening pressure to a normal of less than 20 cm H2O. Ventriculoperitoneal shunts can be placed only if more conservative measures to control increased ICP have failed.
      • Abassi M.
      • Boulware D.R.
      • Rhein J.
      Cryptococcal meningitis: diagnosis and management update.
      • Perfect J.R.
      • Dismukes W.E.
      • Dromer F.
      • et al.
      Clinical practice guidelines for the management of cryptococcal disease: 2010 update by the Infectious Diseases Society of America.
      After induction therapy with liposomal amphotericin B and flucytosine and repeated LP, the patient’s symptoms improved dramatically. Morning headaches resolved, and mental status returned to his baseline. He was being prepared for hospital dismissal with appropriate follow-up.
      • 5.
        Which one of the following would be the preferred follow-up after starting induction therapy for CM in this patient?
        • a.
          Daily measurement of electrolytes and magnesium
        • b.
          Weekly measurement of electrolytes and magnesium
        • c.
          Daily measurement of serum cryptococcal antigen
        • d.
          Weekly measurement of CSF cryptococcal antigen
        • e.
          Weekly measurement of CD4 and CD3 counts
      Although induction therapy with liposomal amphotericin B and flucytosine has been found to improve mortality in CM, it is important to recognize the severe adverse effects these medications can have. Amphotericin B deoxycholate in particular is known to be nephrotoxic and causes major electrolyte abnormalities that can be life-threatening. Although lipid formulations of amphotericin B are less nephrotoxic, they still require monitoring of creatinine and electrolyte levels. Potassium and magnesium wasting typically begins after 5 days of amphotericin therapy.
      • Abassi M.
      • Boulware D.R.
      • Rhein J.
      Cryptococcal meningitis: diagnosis and management update.
      Flucytosine also has hematologic adverse effects, including leukopenia and thrombocytopenia, that can worsen in acute-on-chronic kidney disease. As such, it is important to obtain daily electrolyte measurements to monitor for and treat these abnormalities. Daily measurement of serum cryptococcal antigen and weekly measurement of CSF cryptococcal antigen are not reliable measures to provide therapeutic monitoring and thus are not routinely recommended for that purpose.
      • Antinori S.
      • Radice A.
      • Galimberti L.
      • Magni C.
      • Fasan M.
      • Parravicini C.
      The role of cryptococcal antigen assay in diagnosis and monitoring of cryptococcal meningitis [letter].
      Because CM can be seen in apparently immunocompetent individuals, measurement of CD4 and CD3 counts would not help predict response to therapy.

      Discussion

      Cryptococcal meningitis is a devastating opportunistic infection caused by the encapsulated yeast C neoformans. It is often considered in HIV-infected patients, but it can occur in patients with impaired cell-mediated immunity from other etiologies.
      • Lin Y.Y.
      • Shiau S.
      • Fang C.T.
      Risk factors for invasive Cryptococcus neoformans diseases: a case-control study.
      In a US study of more than 300 HIV-negative patients with cryptococcal infection, half had CNS involvement, and of these, 25% had received corticosteroid therapy, 24% had chronic liver, kidney, or lung disease, 16% had a malignancy, 15% had received solid organ transplants, and 30% had no apparent underlying condition.
      • Pappas P.G.
      • Perfect J.R.
      • Cloud G.A.
      • et al.
      Cryptococcosis in human immunodeficiency virus-negative patients in the era of effective azole therapy.
      These findings are important given the considerable morbidity and mortality regardless of HIV status, making early recognition key to expedite management.
      • Williamson P.R.
      • Jarvis J.N.
      • Panackal A.A.
      • et al.
      Cryptococcal meningitis: epidemiology, immunology, diagnosis and therapy.
      Our patient has 2 risk factors that impair cell-mediated immunity, including sarcoidosis and corticosteroid therapy, which predisposes him to CM.
      Patients with CM usually present with subacute or chronic meningitis symptoms of a few weeks’ duration. However, these symptoms, such as headache and altered mental status, are not specific. When suspected, LP is the best first step in diagnosing CM. Typically, CSF studies will reveal a high opening pressure, lymphocytic pleocytosis, low glucose concentration, and high protein level. In general, CM should be considered in all cases of lymphocytic meningitis. Cerebrospinal fluid cryptococcal antigen testing has a rapid turnaround time and can establish the diagnosis with high specificity and sensitivity.
      • Tanner D.C.
      • Weinstein M.P.
      • Fedorciw B.
      • Joho K.L.
      • Thorpe J.J.
      • Reller L.
      Comparison of commercial kits for detection of cryptococcal antigen.
      • Abassi M.
      • Boulware D.R.
      • Rhein J.
      Cryptococcal meningitis: diagnosis and management update.
      Serum cryptococcal antigen testing is helpful especially in situations in which CSF assessment is delayed for any reason. Additionally, fungal cultures of blood and CSF specimens can be helpful in the diagnostic work-up.
      The cryptococcal polysaccharide capsule causes a physical obstruction of the arachnoid villi, which leads to a failure to resorb CSF and in turn elevated ICP.
      • Williamson P.R.
      • Jarvis J.N.
      • Panackal A.A.
      • et al.
      Cryptococcal meningitis: epidemiology, immunology, diagnosis and therapy.
      Interestingly, the elevation in ICP is positively correlated with an increased number of organisms in the CSF. One feared complication of intracranial hypertension is cerebral edema. Common symptoms and signs include headaches, vomiting, visual changes, papilledema, abducens nerve palsy, altered mental status, and ultimately coma. Increased ICP in patients with CM should be managed aggressively to decrease morbidity and mortality and is usually achieved using serial LPs.
      • Perfect J.R.
      • Dismukes W.E.
      • Dromer F.
      • et al.
      Clinical practice guidelines for the management of cryptococcal disease: 2010 update by the Infectious Diseases Society of America.
      Once the diagnosis of CM is confirmed, it is important to promptly initiate appropriate antifungal therapy. Although fluconazole monotherapy can be used for mild cryptococcal disease not involving the CNS, treatment of CM is lengthy and arduous and includes 3 stages: induction, consolidation, and maintenance. Induction therapy consists of deoxycholate or lipid formulations of amphotericin B plus flucytosine for 4 to 6 weeks. Subsequently, consolidation therapy should be initiated with fluconazole (800 mg/d orally) for 8 weeks. Following that, maintenance therapy with fluconazole (200 mg/d orally) should be given for 6 to 12 months.
      • Perfect J.R.
      • Dismukes W.E.
      • Dromer F.
      • et al.
      Clinical practice guidelines for the management of cryptococcal disease: 2010 update by the Infectious Diseases Society of America.
      Of note, all these medications can have serious adverse effects. Amphotericin B products in particular can lead to nephrotoxicity, in addition to potassium and magnesium wasting. Flucytosine can also cause neutropenia, especially in patients with chronic kidney disease. Therefore, it is extremely important to monitor electrolyte levels and complete blood cell counts closely. In addition, patients should be monitored clinically for infusion-related reactions during and following each administration. Lumbar puncture is repeated 2 weeks after induction therapy in immunocompromised hosts to assess response to therapy by the presence or absence of fungal growth.

      Conclusion

      It is important to recognize CM at an early stage given its high morbidity and mortality if adequate treatment is not started promptly. The HIV-negative status may lead to a delay in diagnosis, so it is helpful to consider other risk factors that impair cell-mediated immunity, especially prednisone use, which in turn predisposes patients to CM.

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