1. Case Study 37
By Chris Sanders

2. History of Present Illness
86 y.o. male
Mosquito bite
Swelling around right eye
Bit 96 hours ago
Severe periorbital edema
Mild fever
Mild headache

3. Review of Systems Alert and oriented Doctor suspects arthropod
Follow up appointment with neurologist and infections diseases specialist
OTC ibuprofen
Ice to swollen area

4. Acute Viral Encephalitis
What is the pathophysiology of swelling in this case?
Why is the application of ice helpful to relieving swelling in this case?
Based on the patient’s location when he received the mosquito bite, what are several possible diagnoses?
Based on incubation period only, identify two potential types of encephalitis in this patient.
Are any of the infections that you listed above in your answer to question 3 potentially serious?

5. Clinical Course
Confused
Disoriented
Mild tremors
Severe headache

6. Previous Medical History
18 months S/P cadaveric renal transplantation
ESRD secondary to DM type 1, diagnosed 10 yrs
CAD
COLD x 6 yrs
Asthma
DM type 1 diagnosed at 13

7. Medications Nitroglycerin SR 6.5 mg po Q 8h
Nitroglycerin 0.4 mg SL PRN
Theo-Dur 100 mg po BID
Albuterol MDI 2 puffs QID PRN
Atrovent MDI 2 puffs BID
Cyclosporine 250 mg po BID
Prednisone 10 mg po QD
Mycophenolate mofetil 1500 mg po BID
Insulin: NPH insulin 16 breakfast and Lispro
Blood Glucose (mg/dL)
breakfast
lunch
supper
Bedtime
<80 4 -
81-150 5 8 6 9 1 7 2 10 3 11 12 13
>400 14

8. Three of the drugs listed above are of particular concern in this patient. Which three drugs should cause concern and why should they cause concern?

9. Nitroglycerin
Dizziness, headaches, lightheadedness
Theo-Dur
Dizziness, headaches, lightheadedness
Albuterol
Dizziness, headaches
Atrovent
Headache, eye pain
Cyclosporine/Prednisone
Suppresses immune system
Mycophenolate mofetil
Suppresses immune system

10. PE and Lab Tests Disoriented, pale, mild tremors, appears ill
BP 150/95
P 105 and regular
RR 17 and unlabored
T 100.5º F
Warm and pale skin
No rash observed

11. PE and Lab Tests Cont. PERRLA EOM intact
Fundi reveal old laser scars bilaterally w/o hemorrhages and occasional hard exudates bilaterally
Ears and nose unremarkable with no bulging of TMs
Mucous membranes dry
Mild non-exudative pharyngitis present
Wears dentures

12. PE and Lab Tests Cont. Thyroid normal
Cervical and axillary lymph nodes palpable (~2cm)
Sinus tachycardia
Chest normal
Abd normal
Rect normal
Ext normal

13. PE and Lab Tests Cont. Disoriented Mild tremor in both hands DTRs 2+
(+) Kernig sign
(+) Brudzinski sign
Muscular strength 3/5
Decreased sensation in feet (diabetic neuropathy)

14. Suggest a reasonable explanation for the laser scars in the eyes?
Suggest a reasonable pathophysiologic explanation for the patient’s enlarged lymph nodes.
Although not routine practice, why were this patient’s feet carefully examined for lesions?
What is suggested by the positive Kernig and Brudzinski signs?

16. Lumbar Puncture Results
Significant lymphopenia
Mild diffuse cerebral edema with no intra-cerebral bleeding
CSF lymphocytosis
Normal glucose
No CSF RBCs
Moderately elevated protein
Normal lactic acid
Gram stain (-)
Bacterial culture (-)
IgM antiviral antibody (+)
Enzyme Immunoassay with Plaque Reduction Neutralization Test
West Nile Virus

17. Based on all the available clinical evidence above, what is a likely diagnosis for this patient’s condition?
What is an appropriate treatment approach for this patient?