A 36-year-old man is brought to the emergency department by his roommate with confusion and agitation for the last 2 days. While in the emergency department, he has generalized tonic-clonic seizures. The patient's other medical problems include alcohol abuse and illicit drug use. He was hospitalized 6 months ago for alcoholic pancreatitis. His temperature is 40.0 C (104.0 F), blood pressure is 120/80 mm Hg, and pulse is 105/min. He is confused and disoriented. Funduscopy is within normal limits, and there is no neck stiffness. Neurologic examination shows upgoing plantar reflexes bilaterally. CT scan of the head reveals no abnormalities. Lumbar puncture is performed, and cerebrospinal fluid analysis results are as follows: Gram stain shows no bacteria. Further cerebrospinal fluid studies are pending. Which of the following is the best next step in management of this patient?

Question

A 36-year-old man is brought to the emergency department by his roommate with confusion and agitation for the last 2 days.  While in the emergency department, he has generalized tonic-clonic seizures.  The patient's other medical problems include alcohol abuse and illicit drug use.  He was hospitalized 6 months ago for alcoholic pancreatitis.  His temperature is 40.0 C (104.0 F), blood pressure is 120/80 mm Hg, and pulse is 105/min.  He is confused and disoriented.  Funduscopy is within normal limits, and there is no neck stiffness.  Neurologic examination shows upgoing plantar reflexes bilaterally.  CT scan of the head reveals no abnormalities.  Lumbar puncture is performed, and cerebrospinal fluid analysis results are as follows:  Gram stain shows no bacteria.  Further cerebrospinal fluid studies are pending.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

11ec25c8_d1b3_a1d7_bc81_bd976eda6314_MD0003_00 This patient's presentation is consistent with viral encephalitis. The majority of acute viral encephalitis cases are due to unknown causes. However, herpes viruses (eg, herpes simplex, varicella, Epstein-Barr) most commonly cause encephalitis in immunocompetent adults. Patients typically present with fever, altered mental status, agitation, headaches, and seizures that can rapidly progress to complete unresponsiveness or coma. Examination can show neurologic abnormalities, including hemiparesis, cranial nerve palsies, and exaggerated deep-tendon reflexes. Clinical signs of meningeal irritation (eg, photophobia, nuchal rigidity) are usually absent in patients with pure encephalitis. Lumbar puncture usually shows cerebrospinal fluid (CSF) findings of elevated white blood cell count with lymphocytic predominance, normal glucose, and normal to slightly elevated protein concentration (generally 100 mg/dL). Most patients have an increased red blood cell count as well. Diagnosis is usually confirmed by detecting viral DNA by polymerase chain reaction (PCR) in the CSF. Empiric treatment with intravenous acyclovir should be started while awaiting PCR results as encephalitis is often associated with significant morbidity and mortality. (CSF) findings (Choice B) Intravenous amphotericin (plus flucytosine) is used for induction therapy in patients with cryptococcal meningoencephalitis. Cryptococcal meningitis is usually a subacute meningitis, and patients commonly present after weeks of symptoms. It is most commonly seen in immunocompromised patients (eg, those with HIV). Symptoms are due to increased intracranial pressures (headache) from capsular swelling; almost all patients have markedly elevated opening pressure on spinal tap. This patient's rapid onset of symptoms, presentation more consistent with encephalitis, and normal opening pressure make cryptococcal meningitis very unlikely. (Choice C) Intravenous ceftriaxone and vancomycin (and ampicillin in adults age >50) are empiric treatments for bacterial meningitis. CSF analysis in these patients typically shows elevated white blood cell counts with neutrophil predominance, low glucose, and elevated protein concentration (often >250 mg/dL). (Choice D) Magnetic resonance imaging of the brain is sensitive for detection of demyelination or other focal abnormalities of the temporal lobe that suggest herpes simplex virus encephalitis. However, empiric treatment with intravenous acyclovir should be started as soon as possible in patients with suspected viral encephalitis without waiting for further imaging studies. (Choice E) Chlordiazepoxide is used to treat alcohol withdrawal in hospitalized patients. Withdrawal can begin within 1-2 days of stopping alcohol and presents with tremulousness, anxiety, headache, and palpitations. These can progress to fever, hypertension, and delirium tremens. This patient's CSF findings (eg, elevated protein & WBC), however, are more suggestive of viral encephalitis. Educational objective: Viral encephalitis can present with cerebrospinal fluid findings of elevated white blood cell count with a lymphocytic predominance, elevated red blood cell count, normal glucose, and normal to slightly elevated protein concentration. Early empiric therapy with intravenous acyclovir should be initiated as soon as possible for suspected herpes simplex virus encephalitis until confirmatory tests return. References: Viral encephalitis. (http://www.ncbi.nlm.nih.gov/pubmed/15761675)

A 36-Year-Old Man Is Brought to the Emergency Department by His