A 28-year-old man presents to
the emergency department
with high fever; progressive, severe,
generalized, throbbing headache;
blurred vision; and increasing
confusion. These symptoms started
3 days earlier.
History. The patient had previously
been healthy and active; he
works in the oil fields. He is married
and does not smoke, drink alcohol,
or use illicit drugs. He has had no
blood transfusions and takes no
Examination. This well-built man
appears ill. Pulse rate is 110 beats per
minute; temperature, 38.3C (101F);
respiration rate, 22 breaths per minute;
blood pressure, 116/72 mm Hg.
He is well hydrated. No scleral icterus
or oral candidal infection. Pupils are
equal and reactive. No palpable adenopathy
or rashes. The patient is confused;
disoriented to person, time,
and place; and agitated. Cranial nerves
are intact. Fundi are normal. He can move all his limbs.
Deep tendon reflexes are normal; plantar reflexes are
equivocal. Neck is supple. Remainder of the examination is
Laboratory studies. White blood cell (WBC) count,
L, with 70% polymorphonuclear neutrophils and
30% lymphocytes. Hemoglobin level is 13.1 g/dL; platelet
L; erythrocyte sedimentation rate,
90 mm/h. Serum sodium level is 138 mEq/L; potassium,
4 mEq/L; chloride, 102 mEq/L; calcium, 9.2 mg/dL;
blood glucose, 101 mg/dL; blood urea nitrogen, 29 mg/dL;
serum creatinine, 1 mg/dL; total bilirubin, 1 mg/dL;
aspartate aminotransferase, 22 U/L; alanine aminotransferase,
26 U/L; alkaline phosphatase, 112 U/L. Results of
coccidial serologic testing and drug screening are negative.
Urinalysis results are normal.
Cerebrospinal fluid (CSF) pressure is increased. CSF
protein level is 180 mg/dL; glucose, 92 mg/dL; WBC count,
L (all lymphocytes); red blood cell count, 80/µ
Gram staining of CSF shows WBCs but no organisms.
You order an MRI scan of the brain.
What abnormalities are evident here—and to what
diagnosis does the clinical picture point?
A. Viral meningitis
B. Acute multiple sclerosis
C. Multifocal leukoencephalopathy
D. CNS lymphoma
E. Herpes encephalitis