<Presentation of a
case>
This 67 year-old man, an aborigines and a retired fisher
living in the countryside of Taitung, had been well until 25
August, 2006 when he began to experience generalized headache,
general myalgia, and arthralgia over multiple joints that
continued for one month prior to this admission. He had no
history of head injury, fever, night sweats or weight loss.
Gradual onset of ptosis of the right eye was found by his
family at the same time. The symptoms progressed and he sought
medical attention at the Emergency Department of Tzu-Chi
Hospital in Hua-Lien on 24 September, 2006, where computed
tomography of the brain did not reveal any specific lesion.
Two days later, he was brought to our outpatient department on
26 September, 2006 for second opinion because his movement
became retarded. He was admitted to our ward for further
evaluation and treatment.
According to his statement, he did not raise pets, but he
fed chicken in the court. He had no recent travel. He used to
eat cooked snails several times a week since he was young. He
denied a history of tuberculosis or use of Chinese herb
remedies or over-the-counter medicines.
On admission, his consciousness was clear but speech was
sluggish. The body temperature 37.2℃, pulse rate was 76 beats
per minute, and respiratory rate was 20 breaths per minute and
the blood pressure was 104/60 mmHg. His conjunctiva was pink
and sclera was not icteric. The pupils were isocoric with
prompt reaction to light. Right eye was ptotic but the eye
movement was intact. There was no oral thrush or oral ulcers
in the oral cavity. The neck was supple without
lymphadenopathy, engorged jugular veins, palpable thyroid
gland or carotid bruits. The chest wall expansion was
symmetric, and breath sounds were bilaterally clear. The heart
beats were regular without audible murmur. The abdomen was
soft. Bowel sounds were normoactive and liver and spleen were
impalpable. His extremities were freely movable without edema.
There was no cyanosis, petechiae, purpura or pigmentation. The
genitalia were free of ulcers and discharge.
<Laboratory
data>
1.
Hemogram
CBC+PLT |
WBC K/μL |
HB g/dL |
HCT % |
MCV fL |
PLT K/μL |
Band % |
Segment % |
Eos % |
950925 |
4.41 |
14.2 |
41.6F |
94.3 |
151 |
3 |
26 |
40 |
951002 |
9.41 |
14.2 |
42.9 |
96.6 |
154 |
0 |
62.1 |
0.7 |
951018 |
3.66 |
14.1 |
43.6 |
98.4 |
132 |
0 |
39.6 |
16.7 | 2. Biochemistry (BCS) and
electrolytes
BCS |
T-Bil U/L |
GOT U/L |
ALP U/L |
r-GT U/L |
LDH U/L |
BUN mg/dl |
Cre mg/dl |
Uric Acid mg/dl |
950925 |
0.89 |
28 |
168 |
36 |
405 |
11.2 |
0.7 |
5.7 |
BCS |
Na mmole/l |
K mmole/l |
Cl mmole/l |
Ca mmole/l |
Mg mmole/l |
950925 |
140 |
3.7 |
106 |
2.24 |
405 |
3. Stool
examination Egg
concentration (III sets): no parasite ova were
identified.
4.
Cerebrospinal fluid (CSF) study
CSF |
Appearance |
Opening pressure (mmH2O) |
Closing Pressure (mmH2O) |
Protein g/dl |
glucose mg/dl |
WBC cells/ul |
L:N:Eos |
RBC /ul |
950925 |
Clear |
165 |
120 |
0.104 |
47 |
150 |
62:2:86 |
0 |
CSF |
AFS |
TB culture |
Virology |
Bacterial |
Fungus |
Weil- Felix |
Widal |
950925 |
Negative |
Negative |
Negative |
Negative |
Negative |
Negative |
Negative |
CSF |
India ink smear |
Cryptococcal Antigen |
VDRL |
Cytology |
950925 |
Negative |
Negative |
Negative |
Negative |
<Course and treatment>
After admission, a lumbar puncture was
performed. The CSF was clear; however, it showed pleocytosis
with eosinophil predominance
(Lymphocyte/Neutrophil/Eosinophil: 62/2/86). No parasite was
seen by microscopy. Praziquantel was prescribed for six doses
and ivermectin 12mg was given. Magnetic resonance imaging
(MRI) of the brain showed mild nonspecific white mater change.
The follow-up eosinophil count showed decreasing, and he felt
improvement. Steriods were tapered. However, the eosinophil
count increased to about 600 cells/μL. Another dose of
ivermectin was given on 11 October 2007. Bone marrow biopsy to
search for other causes of hypereosinophilia showed erythroid
hyperplasia with an increased number of eosinophils. We sent
the CSF specimens to Professor Huang Kao-Pin's (黃高彬)
laboratory where a positive antigen test for Angiostrongylus
cantonensis was found.
<Discussion>
- Eosinophilia is defined as the presence of more than 500
eosinophils per microliter of peripheral blood. The common
etiologies are infection, inflammation, iatrogenic agent and
malignancy. Eosinophilic meningitis is defined as the
presence of 10 or more eosinophils/uL in the CSF specimen or
eosinophilia of at least 10% of the total CSF leukocyte
count. The common etiologies of eosinophilic meningitis are
infections with parasites, fungi, bacteria, rickettsiae, and
viruses and malignancy. A. cantonensis is the leading
etiology of eosinophilic meningitis caused by parasites.
Reaction to 31KD monoclonal antibody of A. cantonensis is
found to be diagnostic, with sensitivity of more than 90%
and specificity of nearly about 100%. The pumping lumbar
puncture method has been found to increase the recovery rate
of the A. cantonensis larva. Larva recovery rate ranges from
24% to 50%. The incubation period was 2 to 35 days.
Headache, nuchal rigidity, and visual disturbance are common
clinical manifestations. Fever is seen in less than half of
the patients with eosinophilic meningitis due to A.
cantonensis. Paresthesia and hyperesthesia of the
extremities, trunk or face are the most distinctive
neurological findings. Paralysis of the extraocular or
facial nerve, delirium, seizures, and persistent cognitive
dysfunction have been reported. Most of the symptoms were
self-limiting. Steroids and larvicidal agents could help
improve the symptoms. Most of the cases were reported from
southern and eastern Taiwan.
<References> 1. Am J Med. 2003;114:217-23. 2. Southeast
Asia J Trop Med Public Health 2003;34;1-6. 3. Clin Infect
Dis 2001;33:112-5. 4. Southeast Asian J Trop Med Public
Health
1991;22:194-9.
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