Cerebral neuroschistosomiasis presenting as a brain mass. A case report.
Ahmad S. Matarneh 1, Mohanad M. Faisal 1, Salma F. Mustafa 1, Abdulla M.
Arshad 1, Nedia Neffati 2.
Internal medicine resident, Hamad medical corporation, Doha, Qatar
Consultant, Internal Medicine, Hamad Medical Corporation, Doha, Qatar
*Corresponding Author
Dr. Salma Faisal Eltayeb Mustafa
Department Internal Medicine.
Hamad Medical Corporation.
Al Rayyan street.
Doha, Qatar.
Tel: +97466098858
Fax: –44397857
E-mail: Smustafa8@hamad.qa
Running title:
A brain mass caused by neuroschistosoma.
Abstract
Neuroschistosomiasis is an extremely rare manifestation of schistosomal
infections. It can either present with Cerebral or with spinal cord
involvement.
We present a 31-year-old fillipino lady, presented with two-weeks
history of headache, dizziness and nausea. An urgent MRI of the head
with contrast showed features suggestive of brain lesion with edema. On
further history taking she had a history of working in a farm. Serology
for Schistosoma was sent and came positive with titre 1:160. She was
treated as neuroschistosomiasis with intravenous steroids followed by
praziquantel for 10 days along with steroids after which he showed
significant improvement in her headache and significant regression in
the brain lesion on MRI.
Cerebral neuroschistosomiaisis is a rare complication of schistosoma
infection it should be kept in mind when dealing with an unexplained
brain lesion. If not treated promptly, it can result in severe
irreversible complications.
Introduction :
Schistosomiasis is a helminthic disease which is more commonly seen in
the Middle East (1). Infection usually occurs after contact with snails
that contains the eggs and parasite which are the intermediate host.
Snails then release cercariae, the infectious form of the parasite into
the water, cercariae can penetrate the skin of the host and thus causing
the infection (2). Neuroschistosomiasis is rare. It can either involve
the brain or it can involve the spinal cord (3). In this case, we
present a rare case in which the patient presented with headache and was
found to have brain lesion secondary to neuroschistosomoiasis, the
patient showed significant improvement after treatment with praziquantel
and steroids.
Case presentation:
A 31-year-old Filipino lady, previously well presented to the hospital
with weeks history of headache, dizziness, and nausea with vomiting. She
had no chronic medical condition or previous similar episodes. On
examination, vital signs showed normal temperature with normal BP 115/71
and HR of 87. Neurological examination revealed well oriented lady,
normal fundoscopy, normal power, sensation, and deep tendon reflexes.
Basic investigation revealed high inflammatory markers with pyuria and
acute kidney injury as depicted in the below (table 1)
Plain CT head showed Ill-defined right occipitoparietal hypodensity with
mass effect and suspicious right occipital density (Figure 1).
Intravenous Dexamethasone was started, and the patient was admitted
under neurosurgery. brain MRI was obtained which revealed Right medial
parieto-occipital essentially cortical irregular curvilinear/punctate
enhancing lesion with the significant adjacent surrounding
subcortical/white matter oedema (Figure 2). Lumbar puncture showed
normal studies. Schistosoma antibodies were positive, and she was
started on praziquantel along with dexamethasone. Subsequently, the
patient improved clinically and was discharged home. On follow-up
visits, she had improvement of her symptoms, and follow up MRI head
showed significant regression in the brain lesion (figure 3).
Discussion:Schistosomiasis is a rare helminthic disease caused by Schistosoma
flukes; however, it is regarded as the second most common tropical
disease (5). It can affect multiple organs including the liver,
intestines, urinary bladder, central nervous system. There are several
known types of Schistosoma, S. Haematobium, S. Japonicum, S. Mansoni,
and S. Mekongi (4). Neuroschistosmiasis is usually rare and multiple
theories have been studied on its pathophysiology, but the most accepted
is that it results from the embolization of the organism’s eggs until it
lands in the central nervous system. After reaching the central nervous
system, Schistosoma eggs usually induce a local eosinophilic
inflammation resulting from the release of proteolytic enzymes. The
resultant inflammation causes damage with granuloma formation and
eventually fibrosis and demyelination of the surrounding structures (7).
Its manifestations are divided into cerebral Schistosoma, which occurs
when S. Japonicum reaches the brain causing encephalitis, which presents
with symptoms of headache, seizures, altered mentation, or the spinal
schistosomiasis resulting from S. Mansoni (and less commonly S.
Hematobium) where it can cause myelitis with symptoms of weakness, back
pain, and urine retention (6)
Diagnosing neuroschistosomiasis can be challenging as it requires a high
index of clinical suspicion. MRI is the gold standard diagnostic study
to diagnose CNS involvement and it can detect changes consistent with
cerebritis, cerebral mass (8, 9). Definite diagnosis is usually invasive
as it requires tissue biopsy. Serology is a sensitive test for the
diagnosis, but with low specificity as the false positivity is common,
however when the titers are positive in high titers
(>1:160) they are considered significant (10, 11).
After establishing the diagnosis, prompt treatment should be started as
it has been shown to improve the outcome. Steroids need to be started
before praziquantel to decrease the inflammation that might result from
the cytotoxic effect of praziquantel on the organism (12).
Praziquantel’s mechanism of action is that it causes tetanic
contractions paralyzing the organism (13). It acts only on the mature
adult worms and not the larval form making it ineffective in the early
stages of infection (14).