Download Echinococcosis (Hydatid Disease)

Echinococcosis (Hydatid Disease)
• Echinococcus granulosus
• Echinococcus multilocularis.
• Humans acquire the infection when they
become intermediate hosts of these
tapeworms by accidental ingestion of the eggs
of Echinococcus Spp.
• After entering the body, the eggs transform
into cysts that grow in tile liver, lungs, heart,
and CNS .
• In the latter, cysts may also result from
metastatic dissemination of a visceral cyst.
Cystic Hydatid Disease
(Echinococcus granulosus)
• Seizures.
• increased intracranial pressure.
• focal neurological deficits.
• Orbital involvement : proptosis and
ophthalmoplegia
Diagnosis
• large non enhancing vesicle that is well
demarcated from the surrounding brain
parenchyma.
• Some lesions may be calcified.
• epidural cysts have a biconvex shape or a
multilocular appearance and may be
associated with bone erosion.
Giant" cysticercal cyst in the right sylvian fissure“
Intraventricular cysticercus
Diagnosis
• enzyme-linked immunosorbent assay (ELISA)
• enzyme-linked immunoelectrotransfer blot
(EITB)
• false-negative results in up to 50%.
Pathology
• E. granulsus cysts are large, spherical, and
well demarcated from surrounding tissue.
• within the CNS, these cysts may be located in
the brain parenchyma, ventricular system,
subarachnoid space, epidural space, orbits,
and both the epidural and subarachnoid
spaces in the spinal canal.
Pathology
• epidural cysts tend to be associated with
vertebral bone erosion.
• Primary hydatid disease of the heart may be
the source of an embolic cerebral infarction,
usually in the territory of the middle cerebral
artely.
Treatment
• Antiparasitic drugs are usually given before
surgical resection in the case of intraoperative
rupture of cysts or postoperatively to treat
recurrent hydatid disease.
CYSTIC HYDATID DISEASE OF THE
BRAIN
• Dowling's technique:
hydrostatic expulsion of the entire cyst by
irrigation of saline solution between the lesion
and the surrounding nervous tissue.
• The aim of this technique is to remove the
cyst without damaging its walls.
accidental intraoperative rupture
• 25% of cases.
• allergic reaction.
• recurrent hydatid disease.
Complications: subdural effusions
and intracranial hemorrhages.
• some surgeons puncture the cyst, aspirate its
contents, irrigate the cyst with a hypertonic
saline solution, and then remove the shrunken
cyst.
Albendazole
• 10 to 15 mg/kg per day.
• several 1-month cycles with therapy-free
intervals of 14 days between cycles.
• Cured 28% of patients and improved the
condition of 51% of other 72%
Albendazole
• Patiens not candidates for surgical resection of
lesions.
• prophylactic therapy for those at risk for
accidental rupture of the cysts perioperatively,
• recurrent cystic hydatid disease after surgery.
• combined albendazole and praziquantel tllerapy may
be more effective than albendazole alone for
preoperative prophylactic treatment.
CYSTIC HYDATID DISEASE OF THE
SPINE
• The surgical approach to patients with spinal
hydatid disease usually includes a
combination of :
• decompressive laminectomy,
• removal of cysts.
• excision of involved bone.
• stabilization of the spine.
• Almost 50% of these lesions may rupture
during surgery because of the narrow space in
which the surgeon has to work.
• involvement of adjacent bone and multiplicity
of lesions make complete removal of spinal
cysts difficult.
• Hydatid disease recurs after surgery in up to
40% of patients, and this complication is
associated with neurological deterioration.
• albendazole is advised to reduce such
complications.
Alveolar Hydatid Disease
(Echinococcus multilocularis)
• more rapidly
• more severe
• focal neurological deficits, seizures, and
intracranial hypertension.
Diagnosis
• On neuroimaging studies, alveolar hydatid
disease is characterizednby multiple lesions
surrounded by edema, with ring-like
enhancement mimicking other infectious or
neoplastic diseases of the CNS.
• CT is better than MRI for demonstrating lytic
lesions in vertebral bodies.
• Immunologic diagnosis is better with alveolar
echinococcosis than with cystic hydatid
disease.
Pathology
• E. Multilocularis cysts are small, group in
clusters, elici t a severe
• Infiammatory reaction from the host, and
tend to metastasize both locally and distantly
• They are usually located within the brain
parenchyma.
• Primary hydatid disease of the heart may be the
source of an embolic cerebral infarction that is
generally located in the territory of MCA
Treatment
• Alveolar hydatid disease is invasive, and total
surgical removal usually requires resection of
adjacent tissue. This approach may cause
neurological deficits from cysts located in
eloquent cerebral areas.
• Albendazole may be used as primary therapy
in patients with inoperable alveolar hydatid
disease.
• With a combination of surgery and "cysticidal
therapy, 50% of lesions regress, 40% remain
static, and 10% continue to grow.