Focal Seizure in a 5-Year Old
Radiology Cases in Pediatric Emergency Medicine
Volume 4, Case 1
Soledad Ureta Raroque, M.D.
Children's Medical Center of Dallas
University of Texas Southwestern School of Medicine
This is a five year old Latin American female who
presented to the emergency department (ED) after
having a presumed seizure. She was playing in the
school yard when she suddenly lost consciousness and
developed generalized tonic-clonic movements of the
upper and lower extremities for approximately five
minutes. EMS was called and she was brought to the
ED in a post-ictal state. In the ED, she was noted to
develop a two-minute episode of right sided tonic-clonic
movements of the upper and lower extremities with
eyes deviating to the left. She was incontinent of urine.
There were no associated symptoms of fever, cough, or
upper respiratory illness.
Past medical history was significant for an
appendectomy six months prior because of abdominal
pain. The pathology report described a slightly inflamed
appendix with the incidental finding of enterobius
vermicularis within the lumen of the appendix. She also
had a subsequent emergency department visit for
abdominal pain and fever. Her work-up included a
complete blood count, electrolytes, urinalysis, and
abdominal films. She was subsequently discharged
with a diagnosis of benign abdominal pain and fever,
probably due to a viral syndrome. Her travel history
included a trip to Mexico earlier in the year.
Exam: VS T37.6C, HR 110, RR 30, BP 128/62.
The patient appeared sleepy but arousable and
responded appropriately to family members. Her pupils
were equal and reactive. Both tympanic membranes
had good light reflexes, and her neck was supple. Her
breath sounds were clear and equal. She had a regular
heart rate and rhythm with no murmurs. Peripheral
pulses were brisk, with good capillary refill. The
abdomen was soft and non-tender with normal bowel
sounds. There was an appendectomy scar on the right
lower quadrant. No neurological deficits could be
detected. She had no clonus. Her reflexes were
Because of the presentation of a focal seizure, a CT
scan of the head was obtained.
View Head CT image.
A high cut is shown here. The image on the left is
without contrast. The view on the right is obtained after
IV contrast is administered. This CT scan shows a
small intraparenchymal ring-enhancing lesion in the left
parietal lobe near the vertex, with a fair amount of
surrounding edema consistent with neurocysticercosis.
There is no mass effect on the ipsilateral ventricular
system, no hemorrhage, and no extra-axial fluid
collection. This appearance is not specific, as a brain
abscess, tumor, or other lesions may also have this
She was hospitalized overnight and started on oral
carbamazepine. Electroencephalography was
abnormal, showing diffuse slowing, which was greater
in the left hemisphere. Her eye exam showed no
evidence of cysticercosis. She was not treated with
anti-cysticercal drugs but was continued on oral
carbamazepine. She has subsequently remained
1. Onset of a focal, non-febrile seizure, which
subsequently generalizes, suggests a focal CNS lesion.
The use of imaging studies, CT scan in particular, is
warranted to rule out a mass lesion or a bleed which
could be life threatening.
2. Cysticercosis is the most common parasitic
infection of the human central nervous system, mainly
occurring in developing countries. The increasing
number of immigrants from endemic areas in Latin
America, Asia and Africa has resulted in a higher
prevalence of neurocysticercosis in the United States.
Neurocysticercosis affects males and females of all
ages, with a peak incidence between 30 and 50 years
of age. Sixty to ninety percent of patients with
cysticercosis have CNS lesions.
3. Poorly cooked or raw pork is the only source of
human infection for the development of the adult worm
(Tinea solium). Human infection with cysticerci can
involve thousands of organisms obtained from various
sources: ingestion of T. solium eggs in contaminated
food or water; self-infection from the presence of the
adult worm in the intestine; and possibly internal
autoinfection, in which the eggs come in contact with
the stomach acid, thus possibly allowing hatching and
penetration of the larvae into the tissues. Stools of the
patient and the immediate family should be examined
for ova and proglottid of T. solium and treated
accordingly. Prevention involves awareness of the
infection route and the use of good sanitary and
personal hygiene measures.
4. The presence of the adult worm in the GI tract
usually causes no problems other than slight irritation at
the site of attachment or vague abdominal symptoms
(hunger pains, indigestion, diarrhea, and/or
constipation). There may be a low-grade eosinophilia,
usually under 15%. This patient initially presented with
several episodes of abdominal pain, which on one
occasion led to the removal of the appendix. Parasitic
infections may certainly present as abdominal pain, and
further studies on the stool (ova and parasites) may
reveal other ongoing infestations.
5. The brain parenchyma is the most common
location for neurocysticercosis, followed by the
ventricles and subarachnoid spaces. The cysts may be
located anywhere in the brain, most commonly in the
cerebral gray matter, followed by the brain stem,
cerebellum, and spinal cord. When the cysticercus
dies, it sets up an antigenic stimulus resulting in a local
inflammatory process and breakdown of the blood-brain
barrier; as a consequence, contrast enhancement is
seen. The completely calcified lesions of cysticercosis
represent the dead cysticercus larvae and do not
enhance or elicit edema. It is estimated that it takes
4-7 years for the dead larvae to calcify, which may
explain why calcification is much less commonly seen in
the pediatric age group than in adult patients with
cysticercosis. The differences between adults and
children with cysticercosis include: (1) calcifications
being more commonly seen in adults, and (2) diffusely
homogeneous enhancing lesions being more commonly
seen in children. Hydrocephalus may also develop in
25% of patients with neurocysticercosis secondary to
obstruction of CSF outflow or cysts in the basal
cisterns. Occasionally, the parasite may lodge in the
eye, most commonly under the retina in the posterior
pole, often over the macular area. The inflammatory
reaction that ensues may lead to visual loss.
6. It may be difficult to confirm the diagnosis, even
using CT or MRI techniques. Serologic testing can be
helpful; however, there may be cross-reactivity between
cysticercosis and other parasitic infections. The
enzyme-linked immunotransfer blot assay to detect
antibody to T. solium, for serum and cerebrospinal fluid,
is the antibody test of choice. It is available through the
Centers for Disease Control and Prevention. The
antibody assays, however, are rarely positive in children
with solitary parenchymal lesions, but are often positive
in those with inflamed lesions in contact with the
7. The CSF in neurocysticercosis is abnormal in
about fifty percent of cases. The most common finding
is a lymphocytic pleocytosis (>10 wbc/cu mm). The
presence of eosinophils (detected by Wright's stain) in
the CSF is rare and increases the probability of the
diagnosis. It is seen in fifteen percent of cases of
neurocysticercosis. Other laboratory findings in the
CSF that may be associated with neurocysticercosis
include elevated opening pressure in 40% of cases,
elevated protein in 40%, and low glucose in 25% of
8. Therapy for the different forms of
neurocysticercosis must be individualized according to
the level of disease activity, the number of lesions, the
location of the parasite and the presence or absence of
inflammation as determined by CT or MRI of the brain.
Patients with active disease or with multiple uninflamed
cysts can be treated with praziquantel at 50 mg/kg/day
in three divided doses for 15 days. The use of
corticosteroids is recommended for two to three days
before and during drug therapy to minimize the strong
inflammatory reaction of the host to acute destruction of
parasites in the brain. They may however reduce the
effectiveness of the anti-cysticercal drug. Another drug,
albendazole, appears to have the same efficacy as
praziquantel but is not yet approved by the FDA. The
drug is usually given at an oral dose of 15 mg/kg/day in
three divided doses for 28 days; however, shorter
courses for 3-8 days also appear effective. Intraocular
or ventricular cysts may require surgical resection.
9. Patients with inactive disease or calcification
alone do not need anti-cysticercal therapy since these
lesions represent previous cysts destroyed by the host's
immune reaction. Treatment with antiepileptic drugs,
such as carbamazepine and/or phenytoin, is advised
when calcifications are associated with seizures.
Seizures may recur for months and will require
anticonvulsant medication until patients have been
seizure-free for 1 to 2 years.
1. Del Brutto OH, Sotelo J, and Roman GC.
Therapy for Neurocysticercosis: A Reappraisal.
Clinical Infectious Disease 1993;17: 730-5.
2. Davis LE and Kornfeld M. Neurocysticercosis:
Neurologic, Pathogenic, Diagnostic and Therapeutic
Aspects. Eur Neurol 1991;31:229-240.
3. Garcia LS and Bruckner DA. Diagnostic Medical
Parasitology. Amer. Society for Microbiology.
Washington, DC. 2nd edition. 1993;266-280.
4. Peter G (ed). The 1994 Red Book: Report of the
Committee on Infectious Diseases. American Academy
of Pediatrics, Elk Grove Village, IL. 23rd edition.
Return to Radiology Cases In Ped Emerg Med Case Selection Page
Return to Univ. Hawaii Dept. Pediatrics Home Page