Diffuse parenchymal neurocysticercosis - NepJOL

Ankara et.al. Diffuse parenchymal neurocysticercosis Health Renaissance 2015;13(3): 181-184

Case Report

Diffuse parenchymal neurocysticercosis S Ankara, K Dhungel, K Ahmad, M K Gupta, A Panwar Department of Radiodiagnosis and Imaging B.P. Koirala Institute of Health Sciences, Dharan, Nepal

Abstract Neurocysticercosis is the commonest parasitic manifestation of brain and the leading cause of seizure in the developing world. It is caused by the ingestion of Taenia solium eggs through contaminated food and especially pork meat. Computed tomography and magnetic resonance imaging are the modality of choice for diagnosis of neurocysticercosis. We report a case of 65 years old male presented with complaint of seizure, which was diagnosed as diffuse parenchymal neurocysticercosis on computed tomography scan of brain. Keywords: Computed tomography, neurocysticercosis, taenia solium Introduction

disorders. The clinical manifestations vary

Encystations of the larvae of Taenia solium

with the number, size, location and stage of

(pork tapeworm) in the tissues is known as

cysticerci as well as the intensity of the host’s

cysticercosis.

immune response.3

Encystation

of

this

pork

tapeworm in central nervous system is called neurocysticercosis (NCC) and is endemic in

Case report

developing countries. It is considered as the

A 65 years old male presented with multiple

commonest parasitic manifestation of the

episodes of generalized tonic-clonic seizure.

central nervous system leading to seizure in

There was no family history of epilepsy. No

the developing world.1,2 Clinically it can

history of trauma. Physical examination was

manifests

normal and showed no neurologic deficits.

hypertension, cerebellar

as

epilepsy, focal

ataxia,

intracranial

neurological cognitive

signs,

Laboratory tests revealed mild leukocytosis.

decline,

Computed Tomographic (CT) scan of brain

symptoms of hydrocephalus and psychiatric

was

done.

Axial

section

non-enhanced

followed by contrast-enhanced CT of the

Address for correspondence Dr. Sajid Ansari Assistant Professor Department of Radio Diagnosis and Imaging B.P. Koirala Institute of Health Sciences, Dharan Email: [email protected]

brain revealed multiple, small, rounded, well defined hypodense lesions diffusely scattered in 181

brain

parenchyma

involving

bilateral


fronto-temporo-occipito-parietal

lobes

and

scattered in brain parenchyma involving

bilateral cerebellar hemispheres (Figure 1, 2,

bilateral

3 and 4).

lobes and bilateral cerebellar hemispheres.

Figure 1, 2, 3 and 4: Axial section CT image

Calcified mural nodules within some of the

of brain showing multiple, small, rounded,

lesions, suggesting calcified scolex seen in

well defined hypodense lesions diffusely

left

fronto-temporo-occipito-parietal

occipital

Fig. 1

Fig. 2

Fig. 3

Fig. 4

and

right

parietal.

Lesions were also seen in pons, midbrain,

evidence of hydrocephalus. The patient was

thalamus, basal ganglia and corpus callosum.

managed conservatively with albendazole,

Calcified mural nodules are seen within some

dexamethasone and phenytoin. At 3-month

of the lesions, suggesting calcified scolex

follow-up, there was no seizure and the

(Figure 2, 3 and 4) and mild perilesional

patient was on phenytoin.

edema in some of the lesions. There was no 182


Discussion

According to Escobar classification, NCC is (pork

categorized into four stages.7 Stage 1

tapeworm) through contaminated food results

(vesicular stage) is the active or viable stage.

in cysticercosis.4 When the eggs reach the

CT scan shows round, hypodense areas of

intestine,

varying

Ingestion of Taenia solium

their

protective

eggs

coatings

are

in

sizes

and

numbers,

with

destroyed by biliary and pancreatic enzymes

hyperdense eccentric mural nodule within (2-

and released as oncospheres. Then they

4 mm in size) and no perilesional edema. No

traverse the intestinal wall and enter the

evidence of enhancement on contrast study.

bloodstream and are carried to the tissues of

On MRI (magnetic resonance imaging), it

the host and established as larvae. The

appears as CSF-like intensity signal on all

oncospheres lodged in the central nervous

sequences with hyperintense mural nodule

system develops into cysticercus cellulosae

within.

4

This sets up an

Stage 2 (colloidal-vesicular stage) is the

inflammatory reaction in the CNS which

transitional stage. The cysticercus loses the

produces seizures and epilepsy.2

ability to control the host's immune response

Neurocysticercosis is further divided into

and the cyst wall becomes infiltrated and is

parenchymal and extraparenchymal disease.

surrounded by predominantly mononuclear

The CSF (cerebrospinal fluid) migration of

cells. On CT and MRI, it appears as ring

cysticerci to the ventricles, cisterns and

enhancing lesions with perilesional edema.

subarachnoid space or within the eyes or

Stage 3 (granular-nodular stage) is also the

spinal

transitional stage in which host's immune

and known as NCC.

cord

is

called

extraparenchymal basal

response further progresses with collapse of

cisternal NCC along with hydrocephalus has

the cyst cavity. On CT, it appears as small,

disease.

The

intraventricular

mortality rate of about 50%.

and

3

hyperdense,

rounded,

nodular

lesion

Patients with cysticercosis are typically aged

surrounded by edema. On MRI, it appears as

10-40 years. However, cases have been

signal

described in every age group. There is no

perilesional edema.

3

void

in

all

the

sequences

with

gender predilection. Postmortem studies in

Stage 4 (calcified nodular stage) is the

endemic

inactive

areas

neurocysticercal

suggest

that

infections

80%

of

stage

formed

as

a

result

of

dystrophic calcification of the necrotic larva. It

are

asymptomatic.6 Consequently, many cases

is

are never diagnosed or are found incidentally

perilesional edema on CT and on MRI, it is

during imaging procedures. 183

seen

as

calcified

nodule

with

no


seen as signal void in all the sequences with

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