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Chapter 17 • Hydrocephalus in Neurocysticercosis and Other Parasitic and Infectious Diseases
triculomegaly in 204 patients (14.5%). Seventy pa- Transmission and Life Cycle of the Parasite
tients had global dilatation of the ventricles and 67(32.8%) isolated dilatation of the fourth ventricle. In1984, Apuzzo et al. [4] demonstrated in a series of 45 Humans are the only definitive hosts of T. solium, har- cases of intraventricular cysticercosis that the boring the mature tapeworms in the lumen of the fourth ventricle is most commonly affected (24 pa- small intestine. Usually, there are only minimal clini- tients). In 12 cases, the cysticerci were located in the cal symptoms or even no symptoms at all. The mature third ventricle, and in 5, inside the lateral ventricles.
T. solium is composed of a head or scolex that con- This series, however, did not show any case of isolat- tains four suckers and a double crown of hooks, a nar- ed blockage of the temporal horn of the lateral ven- row neck, and a body that is sometimes many meters tricle. Conversely, in our series the presence of cysts long and is composed of hermaphroditic proglottids.
completely blocking the temporal horn is somewhat A few proglottids are released daily from the distal ex- common (Fig. 1). The cysticerci may move from one tremity of the tapeworm and eliminated with the ventricular cavity to another, a fact that has been host's feces. The host thus delivers proglottids with verified during ventriculography [4, 15].
large numbers of fertile eggs to the exterior, wherethey contaminate the soil. These eggs are resistant tobeing dried out and may remain in the soil or waterfor months. In some cases, the eggs are released insidethe intestinal lumen, and these are the eggs releasedwith the host's feces. Around 50% of these eggs are mature and fertile. The usual intermediate host, thepig, becomes infected by ingesting water or food con-taminated by human feces. The parasites then takeshelter in organs with a high oxygenation and move-ment level, such as the brain, chewing muscles,tongue, and heart (Fig. 2). By consuming uncookedpork containing the larva (intermediate form), hu-mans acquire tapeworms – the mature form of theparasite (Fig. 2).
Human cysticercosis may result from two mecha- nisms: autoinfestation and heteroinfestation. In theformer, the proglottids may release the fertile eggsinside the host's intestines, leading to internal self-in-festation. This is considered one of the ways man canbecome infected by T. solium. In order to liberate thelarvae, the eggs need to be exposed to the stomach acid. Thus, vomiting or antiperistaltic movements ofthe intestines push proglottids with fertile eggs to-ward the stomach. These proglottids may, in turn,fragment and release their eggs to the effects of thestomach acids, and suffer, back into the duodenum,intestinal digestion and disintegration of the em-bryophore and release of the oncosphere. In thesmall intestine, the larva attaches itself to the intesti-nal wall using its hooks, and insinuates itself betweenthe epithelial cells of the villi, with the help of cy-tolytic substances secreted by special glands. Itreaches the connective tissue corium and, once thelumen of the capillaries is reached, invades the tis-sues through the blood vessels. Other facts corrobo-rate this infestation mode, such as the presence inone individual of both cysticerci and the maturetapeworm. A history of tapeworm infection is found Fig. 1. a Axial FLAIR MRI demonstrating blockage of the
temporal horn by cysts. b Axial T1-weighted MRI after en-
in 7%-22% of patients with cysticercosis [59]. Exter- doscopic cyst removal nal self-infestation occurs when the individuals are Fig. 2. Life cycle of the parasite
contaminated by their own feces, ingesting eggs or blood stream. The stomach is thus the first barrier proglottids of their own tapeworm [2].
against this infestation, as only eggs whose shells The mechanisms involved in heteroinfestation in- have resisted the gastric acidity will release their clude ingestion of water, vegetables, or fruit contami- oncosphere in the intestinal alkaline medium. Once nated by T. solium eggs, either through poor hygiene liberated in the blood stream, the embryos will be habits or by soil fertilized with human feces. Usually, retained in places where the diameter of the vessels consumption of contaminated pork leads to tape- is too small or the circulation slow (muscle, retina worm infection. However, immune-suppressed indi- viduals may become infected by contaminated pork The larval form of T. solium, Cysticercus cellu- containing larvae.
losae, develops from the embryo. It possesses a The mature proglottids of the T. solium are elim- head and a neck, invaginated inside a vesicle. The inated from the intestine with the feces into the en- head is similar to that of the adult form and the vironment, degenerate, and release the eggs (em- neck is very small; both are wrapped around them- bryophores), which harbor the embryo (hexa- selves. The vesicle is clear, semitransparent, of vari- canth). Once ingested, the egg undergoes the effects able shape, and measures about 10-15 mm; its inte- of the gastric acids and passes to the intestines rior is filled with crystalline fluid. When the cys- where, 24-72 h afterwards, its shell fragments, re- ticercus is located within the cerebral ventricles or leasing the oncosphere. The oncosphere, in turn, in the subarachnoid space around the brainstem, penetrates the intestinal wall with the help of its the head and neck may disappear and secondary hooks, reaches the mesenteric veins and then the vesicles may form from its walls, mostly intercon-

Chapter 17 • Hydrocephalus in Neurocysticercosis and Other Parasitic and Infectious Diseases
nected, taking the aspect of an irregular grape clus- located preferentially at the level of the basal gan- ter (2-15 cm). This cluster is called Cysticercus glia and cerebral cortex due to their increased vas- racemosus [13, 14].
Once implanted in the CNS, the hexacanth begins its development onto the embryonic form, the cys- Pathological Findings in Neurocysticercosis
ticercus [24]. In its first stage of development, calledthe vesicular stage, the membrane is thin and trans- From one to hundreds of embryos may reach the parent, the fluid is clear, and an invaginated scolex is CNS, where they may survive for 1-30 years in the the norm. The cysticerci can remain in this phase or form of Cysticercus cellulosae, or as Cysticercus race- start a degenerative process as a result of the host's mosus (its intermediate form) or even as both forms immune response, which may lead to their destruc- coexisting together. Once settled, the cysticerci, while tion in three stages. The first stage of this process, alive, cause almost no response from the surround- when the vesicular fluid becomes cloudy and the ing tissues. The inflammatory response is related to scolex shows signs of hyalin degeneration, is called the number of parasites and their state of degenera- the colloidal stage. Later on, the walls of the cyst be- tion, which, in turn, depends essentially on the re- come thick and the scolex is transformed into a gran- lease of antigens [26]. In many cases, the immune re- ular mineralized structure. Lastly, the whole parasite sponse develops slowly, allowing the parasites to sur- becomes an inert calcified nodule (Fig. 3).
vive for many years inside the host in a state of The intensity of the tissue changes around the relative immunological tolerance. In some cases the cysticerci depends on which stage the parasites are parasites are rapidly destroyed due to an intense in- in and on their location in the CNS [24]. In the flammatory reaction. This reaction can elicit con- vesicular stage they induce a perilesional inflam- comitant injury to the brain tissue around the cys- matory reaction, composed mainly of lymphocytes, ticerci. Between these two extremes, there is a myriad plasma cells, and eosinophils. In the colloidal stage, of immune response levels. Women have been found a dense collagen membrane is formed around the to present a more intense tissue inflammatory reac- vesicular membrane and the perilesional inflam- tion than men [53]. The human leukocyte antigen matory infiltrate may also endanger the parasite.
(HLA) participates in the pathogenesis of cysticerco- The surrounding brain tissue presents reactive glio- sis. Some cysticerci have HLA molecules adhering to sis, which explains one of the most common clinical their membranes. The parasites covered with HLA manifestations of neurocysticercosis, epilepsy [20, molecules give rise to an inflammatory reaction 22, 52, 53].
more intense than that of cysticerci without those The degeneration is of the hyalin type and is molecules adhering to the surface, probably because characterized by calcification of the parasite struc- HLA molecules are modified by the parasite or be-cause the parasite itself produces an HLA-like mole-cule [20]. Patients with cysticercosis present an ele-vated HLA-A-28 antigen, while the antigen HLA-DQw2 is decreased, with a relative risk of developingthe disease 3.5 times higher in the presence of theantigen HLA-A-28 [21]. These findings suggest thatthe susceptibility or resistance of an individual to de-velop cysticercosis may be related in part to geneticcharacteristics.
The cysticerci are round vesicles of variable size, filled with liquid, constituted by an external layerknown as a vesicular membrane and an internalportion called scolex [24]. The scolex presents astructure that is similar to the adult parasite thatcan be absent in parasites located in the subarach-noid space, especially the basal cisterns, where theygroup in numerous adherent membranous vesi-cles, grouped in clusters. Classically, cysticerci withscolex are called Cysticercus cellulosae and thosewithout scolex, Cysticercus racemosus. Parenchy- Fig. 3. Unenhanced CT scan demonstrating calcifications
mal cysticerci measure about 1 cm diameter, being as a result of cysticercus degeneration

ture. Glial proliferation develops around the in- the interior of the ventricular cavities, leading to ob- flammatory reaction, and there may be damage to struction to the free flow of cerebrospinal fluid neighboring neurons and vessels giving rise to is- (CSF) at the level of the foramen of Monro or the chemic damage to the parenchyma. Rarely, the tis- aqueduct of Sylvius. This process is called granular sue reaction can diffuse to the brain and meninges.
ependymitis and leads to obstructive hydro- The meningeal cysticerci also give rise to the diffuse cephalus. Hydrocephalus may by asymmetrical if formation of a dense exudate in the subarachnoid only one foramen of Monro is obstructed. However, space composed of collagen fibers, multinucleated the development of granular ependymitis due to a giant cells, eosinophils, and hyalinized parasitic cysticercus may not fix it, allowing it still to move membranes, with thickening of the basal meninges.
around. This can lead to transient obstruction by the This chronic inflammation is responsible for the development of hydrocephalus in more than half of Intramedullary forms of the disease have been de- scribed, mainly at the mid-thoracic level, whereas When the cysticercus is located within the ven- spinal subarachnoid localizations are more common tricular system, it also gives rise to intense perile- at the cervical level [7,15].
sional inflammatory reaction (Fig. 4), if they are ad-herent to the ventricular wall. In these cases, theependymal cell layer is altered, forming subependy- Clinical Manifestations and Diagnosis
mal giant cells that tend to group and protrude into With regard to its pathophysiology, neurocysticer-cosis may present as a high- or low-intensity diseasethat may be located in the ventricles, parenchyma, meninges, or mixed location. It may manifest as anacute, subacute, or chronic disease, in remission orexacerbation; it may have a simple or complicatedclinical evolution, be asymptomatic, symptomatic,or fatal. It may subside with or without treatment; itssymptoms may disappear for long periods of time orpersist until death. The onset of the symptoms maybe insidious or abrupt, and the clinical course isvariable and unpredictable. The prognosis is alwayssevere [2].
The clinical presentation may have an insidious beginning and lead to death within a few minutes orin over 30 years' time. The polymorphous nature ofthe symptoms is characteristic of the disease and isdue to a series of factors such as the number, loca-tion, form, size, and stage of development of the parasite, the nature of the parasite's action in thehost's organism, and the host's individual immuno-logical response [63-66]. In 1988, Zee et al. [84] re-ported that out of 46 patients with intraventricularcysts, 6 died of hydrocephalus a short time after ad-mission.
Diagnosis may be reached by appropriate clinical observation that includesepidemiological aspects,clinical and neurological examination, along with de-tailed study of the CSF and imaging studies such ascomputed tomography (CT) and magnetic resonanceimaging (MRI).
Cutaneous cysticercosis may be associated with neurocysticercosis in 65% of the cases. It usuallysuggests a benign neurocysticercosis. The most Fig. 4. a Coronal and b sagittal FLAIR MRI showing intra-
common clinical symptoms of the disease are: ventricular cysts and ependymal inflammatory reaction epilepsy, intracranial hypertension, psychiatric Chapter 17 • Hydrocephalus in Neurocysticercosis and Other Parasitic and Infectious Diseases
changes, meningitis, and meningoencephalitis. Oc- that occurs when cysticerci die and disintegrate, caus- casionally, headache is the only complaint. Al- ing antigen release [54,56].
though the association of these symptoms is com- Intraventricular cysticercosis occurs in 11%-17% mon, isolated epilepsy seems to be the predominant of the patients, being a potentially lethal form of form of presentation. Partial seizures are the most the disease [85]. The oncospheres probably reach frequent; intractable seizures are rare. Intracranial the ventricles through the choroid plexus. They hypertension is usually severe and tends to occur in may develop and float freely in the CSF or adhere association with other symptoms, especially epilep- to the ependyma by a granulomatous reaction. Oc- sy. Its treatment is difficult, although once the acute clusion of the aqueduct or the foramina of Luschka phase has passed, these children frequently present and Magendie may result in acute obstructive hy- a good recovery. Sequelae may ensue in some cases.
drocephalus, sometimes associated with sudden Behavioral disturbances such as aggressiveness, ag- death. Nausea, vomiting, dizziness, headache, itation, and irritability may also be seen. One diplopia, syncope, and altered state of conscious- should bear in mind the possibility of these chil- ness are common manifestations of intraventricu- dren developing a clinical picture of neurological and psychological regression that, when associated CSF analysis is one of the most important exami- with epilepsy, resembles a degenerative disease of nations in the diagnosis of neurocysticercosis, even though the results may be normal in approximately The analysis of the disease is the most important as- 20%-25% of the cases despite the presence of viable pect of its treatment. Neurocysticercosis can be divid- cysticerci. In these cases, an indirect approach to di- ed into two major forms: active and inactive. In the ac- agnosis is a trial drug therapy. In roughly 75% of the tive forms of the disease one may have clinical mani- cases, the immunodiagnosis is positive or, at least, festations such as (1) arachnoiditis, (2) hydrocephalus there are changes in one or more of the CSF parame- due to meningeal inflammation, (3) parenchymal ters. On the other hand, if the patient's condition cysts, (4) cerebral infarction due to vasculitis, (5) mass permits, close clinical observation with CSF exami- effect due to large cysts, (6) intraventricular cysts, and nation, CT, and/or MRI may lead to an unequivocal (7) spinal cysts. The inactive forms present as (1) diagnosis. The definitive diagnosis of neurocysticer- parenchymal calcifications and (2) hydrocephalus due cosis is based on immunodiagnosis in the CSF to meningeal fibrosis.
and/or on lesions suggestive of this parasitic disease Cerebral cysticercosis may be entirely asympto- on CT or MRI. The changes in CSF that characterize matic, being demonstrated only at autopsy. In the the syndrome are lymphocytic pleocytosis, in- symptomatic cases the neurological examination is creased eosinophilic content, elevated total protein normal in 25% of the total [22]. The initial symptoms levels, hypoglycorrhachia, and positive immunolog- that prompt the patient to seek medical help are ical reactions in the CSF. Two or more positive tests seizures, meningeal signs, visual disturbances, increase the certainty of the diagnosis. The comple- headaches, and vomiting. Epilepsy may be an isolat- ment fixation test, one of the first tests utilized for ed symptom for a long time, being called idiopathic the diagnosis of this disease, is positive in 83% of the epilepsy still to the present day. Neurocysticercosis cases of active meningeal cysticercosis if there are may lead to an intracranial hypertension syndrome, inflammatory changes of CSF. Conversely, the test with headache, vomiting, dizziness, and papilledema.
sensitivity is only 22% if CSF examination is normal.
Altered mental status may be a manifestation of the Another immunoassay used nowadays is the en- disease, and pure psychotic forms are found in 15% of zyme-linked radioimmunoassay, which has a speci- the cases. Cysticerci on the motor or sensory cortical ficity of 95% and a sensitivity of 87% in cases of ac- areas can cause seizures, usually generalized. Chron- tive meningeal neurocysticercosis.
ic focal epilepsy is related to residual calcifications Images made by CT scanning vary according to and areas of gliosis that represent the inactive form the phase of maturation of the parasite and its loca- of the disease.
tion. Viability of the cysticercus usually is deter- Meningitis due to neurocysticercosis may show mined by contrast enhancement. Neurocysticerco- acute or chronic headaches, neck pain, and occasion- sis may show on CT as single, multiple, or racemose ally fever. In some cases, the typical presentation of vesicles, generally localized in the brain parenchy- increased intracranial pressure can be seen. In other ma. The cysts have well-defined contours, no perile- cases, meningitis may progress slowly and with only sional edema, and little or no enhancement after mild symptoms, leading to communicating hydro- contrast administration; colloidal-phase cysts show cephalus due to basilar arachnoiditis. The pathogene- perilesional edema, have less defined contours, and sis of neurocysticercosis is that of a chronic inflam- may present annular contrast enhancement sepa- matory process with an irregular period of activation rating the cyst from surrounding cerebral edema.
This tomographic picture was defined as the acute encephalitic phase. Granulomas indicate a degener-ating parasite; they may be single or multiple, ordi-narily nodular and located on the parenchyma. Cal- It is known that neurocysticercosis may be treated cifications are the most common tomographic find- surgically or medically. Surgery for removal of cys- ings. They present as minuscule hyperdense lesions ticerci, employed in only a small and specific num- not surrounded by edema, that do not change after ber of cases (racemose cisternal cysticerci, ventricu- administration of intravenous contrast; they may lar cysticerci), is practically never used in children be single or multiple, of various sizes, always round, as these forms of the disease do not ordinarily occur and appear at least 36 months after the start of the in this age group. Carbamazepine is suggested for degeneration. The presence of diffuse or localized the control of epilepsy because of the increased fre- edema without vesicles in the treated patient may quency of partial seizures. Del Brutto and Sotelo indicate the beginning of the evolutive phase, due to [20-22] demonstrated that 83% of the patients were an inflammatory reaction, hydrocephalus, in- drug-free if anticonvulsants were used in conjunc- creased ventricular size, sometimes in the absence tion with cysticercocidal drug therapy. Conversely, of vesicles, calcifications or granulomas. This is the only 26% of the patients were drug-free when only characteristic pattern of cysticercotic encephalitis, anticonvulsants were utilized. Increased intracra- a particularly severe form of neurocysticercosis in nial pressure is treated specially with dexametha- which the immune system responds actively and in- sone, for a long period, 1 month or more, to with- tensely against a massive invasion of the brain draw slowly. For those few patients who present se- parenchyma by cysticerci.
vere intracranial hypertension that is unresponsive CT findings of subarachnoid neurocysticercosis to dexamethasone, mannitol or a lumboperitoneal include hydrocephalus, abnormal enhancement of shunts might be used as a last resort.
the basal meninges, and cerebral infarction. Ventric- Etiological treatment involves drugs that pene- ular cysticerci may be isodense in relation to CSF, trate the central nervous system and destroy the making their visualization difficult on CT scan. Ven- parasite. Currently two drugs are utilized: prazi- triculography allows precise identification of these quantel (PZQ) and albendazole (ABZ). Their use is restricted to patients who exhibit intact forms of the The MRI characteristics depend on the phase of parasite, i.e., vesicles. The simultaneous administra- the disease. Vesicular cysts are seen as round le- tion of corticosteroids and cysticercocidal drugs to sions with well-defined contours and a signal in- patients with intraparenchymal lesions is also con- tensity similar to CSF in both T1- and T2-weighed troversial [20, 21]. ABZ has been the preferred initial images. The scolex is seen as a hyperdense point cysticercocidal drug, as it is cheaper, has fewer side inside the cystic lesion. The details of the cyst wall effects, and is used for a shorter period of time. If the and perilesional edema, in addition to the pres- lesions persist, PZQ may be used after 3 months, or ence of intraventricular cysts, are better visual- the ABZ treatment may be repeated [7, 16]. PZQ is an ized. All MRI sequences can identify the vesicles.
isoquinoline with strong antiparasitic activity that The degenerating vesicles are recognized by the leads to the disappearance of 60%-70% of intra- presence of edema, which appears bright on T2 se- parenchymal cysts after 15 days of treatment at a quences and is enhanced by contrast material.
dosage of 50 mg/kg per day. ABZ is a benzimidazole Granulomas and residual calcifications appear as with antihelmintic properties, currently the drug of a signal void. These forms of neurocysticercosis choice for the treatment of neurocysticercosis. It de- demonstrate one of the most important diagnostic stroys 75%-90% of intraparenchymal cysts when ad- MRI. MRI easily diagnoses ministered for 8 days at a dosage of 15 mg/kg per day.
meningeal cysticerci, as they present a signal dif- Furthermore, it also acts on the meningeal and in- ferent from the CSF.
traventricular forms of the disease, due to its good In childhood, the diagnosis through imaging penetration into the subarachnoid space [21]. De- demonstrates two factors that are different from the spite treatment with PZQ and ABZ, however, a large disease in adults. The first is the number of lesions: number of patients will require surgical treatment only a small group presents with an intact parasite, to treat hydrocephalus or remove isolated cysts the vesicle; also, most images are from the acute phase (Fig. 5). Patients presenting with compression of cra- of the disease. Secondly, increased intracranial pres- nial nerves, brain tissue, or spinal cord are also sure in infancy is due to cerebral edema from the in- amenable to surgery.
flammatory reaction and not to hydrocephalus sec- Three mechanisms may produce increased in- ondary to ventricular obstruction, the latter being tracranial pressure: diffuse brain edema, hydro- common in adult patients.
cephalus, or mass effect (pseudotumoral form).

Chapter 17 • Hydrocephalus in Neurocysticercosis and Other Parasitic and Infectious Diseases
complished. However, if the cysticerci lie in thecisterns and their degeneration process has al-ready started, complete removal may be difficultor even impossible.
Hydrocephalus can be identified in 15%-30% of thecases with neurological symptoms [42, 51]. in themajority of cases it derives from chronic basalarachnoiditis or meningeal fibrosis. A small per-centage of cases may be due to intraventricularcysts. It is believed that the larvae invade the ven-tricular system through the choroid plexus. Hydro-cephalus corresponds to 90.5% of the cases of in-tracranial hypertension treated with surgery. In- volvement of the ventricular system is ordinarilyassociated with higher mortality and morbidityrates than is the intraparenchymal form of the dis-ease [4, 7, 42, 60]. There is still no consensus in theliterature as to the best kind of treatment. On thewhole, there are three types of treatment: drug ther-apy, which has little or no efficacy in this form of thedisease; ventricular shunts; and surgical removal ofcysts (Fig. 6).
Hydrocephalus may be produced by mechanical obstruction of the CSF pathways by cysts (Fig. 7), in-flammatory reaction caused by cyst degeneration, oran association of both factors. Migration of the cystswithin the ventricles may lead to the intermittentheadaches that characterize Bruns syndrome. Many Fig. 5 a, b. Axial CT scans. a Blockage of temporal horn by
authors recommend ventricular shunts as the first or ependymitis. a Postoperative follow-up after endoscopy
definitive form of treatment [7, 14, 15].
Ventriculoperitoneal shunts are the treatment of choice for those patients who present with inflamma-tory obstruction of the ventricular system and hydro-cephalus. As a rule, the patients exhibit a good recov- Diffuse Brain Edema
ery. However, mechanical and inflammatory compli- This form is found in 2.8% of the cases that presentincreased intracranial pressure. It is seen in cases ofextensive infestation, cysts, inflammatory reaction, and diffuse brain expansion.Treatment is mostly clin-ical, but in intractable cases lumboperitoneal shuntsare indicated. In extreme cases, decompressive cran-iotomies may be performed in a heroic attempt tosave lives.
Giant cysts may be located in the brain parenchy-ma or in the cisterns and are easily identified byimaging studies. If located within the parenchy-ma, complete removal of the cysts is readily ac- Fig. 6. Treatment algorithm for patients with hydrocephalus

Fig. 7. a FLAIR MRI revealing a giant intraventricular cys-
Fig. 8. Axial enhanced T1-weighted MRI. Clusters of cys-
ticercus. b Postoperative T1-weighted MRI. c Cysticercus
ticerci arising from the sylvian fissure. Note the normal ven- cellulosae endoscopically extracted tricular size. b Axial unenhanced T1-weighted MRI,postop-
erative follow-up after endoscopy
cations are prevalent among these patients, with a Pitfalls in Surgical Treatment
high incidence of ventriculitis, meningitis, and ob-struction of the catheter by the cyst. Colli et al. [16] re- Viable intraventricular cysts may shift position fre- port an 82% (46 cases) shunt revision rate in a study quently, moving from the lateral ventricles to the third of 56 patients with neurocysticercosis treated by ven-tricular shunts. In those cases in which ependymitis and fourth ventricles. A recent imaging study, prefer- caused ventricular loculation, an endoscopic proce- ably one obtained during the immediate preoperative dure followed by a ventricular shunt showed good re- period, should allow detection of any cyst migration sults. Free intraventricular cysts, even those located and thus help with the surgical strategy, hopefully pre- inside the third and fourth ventricles and basal cis- venting cysts from being overlooked during surgery.
terns, are easily removed by endoscopic procedures.
Neurocysticercosis is a chronic inflammatory diseasein which there may be communicating and noncom- municating hydrocephalus (Fig. 6).
Cisternal forms with cranial nerve compression It is estimated that 2.4 million people throughout the (Fig. 8) and spinal forms with spine compression have world have cysts from neurocysticercosis in the ven- been described.
tricular cavities [42,70]. The cysts' lack of vasculariza- Chapter 17 • Hydrocephalus in Neurocysticercosis and Other Parasitic and Infectious Diseases
tion and mobility allow easy handling and easy re- intraventricular cysts [4]. The advantages of neuroen- moval in the absence of ependymitis. Large cysts with doscopy are numerous in comparison to craniotomy.
scolex in their interior need to be completely re- Neal in 1995 [40] reported the removal of a cyst of the moved. Even if the cyst ruptures during the proce- posterior portion of the third ventricle, using a com- dure, there is no associated ventriculitis. In the event bination of rigid and flexible endoscope. Irrigation of ependymitis with multiple intraventricular locula- using positive pressure may be another tool to help tions, endoscopy may allow communication between mobilize and aspirate the cysts. In our experience, out various cavities and placement of a single ventricular of 310 patients who underwent endoscopic proce- shunt system. Endoscopic third ventriculostomy is dures, in 20 cases (7.4%) it was for treatment of hydro- typically performed when there is a noninflammato- cephalus associated with the disease. Bergsneider et ry CSF blockage at the level of the aqueduct or fourth al. [9], while studying ten patients with hydro- ventricle (Fig. 6). Once an inflammatory process at cephalus due to neurocysticercosis, concluded that the level of the basal cisterns has occurred, its useful- endoscopic procedures should be considered as the ness is limited. In cases presenting the parenchymal first treatment option. Only three of their patients re- tumoral form of the disease, endoscopy is useful in quired a shunt afterwards.
the removal of cysts and verification of other cystsnot detected by imaging studies. In the severe race-mose form, in which numerous cysts located within Outcome of Hydrocephalus Due to
the interpeduncular cistern may present mass effect and symptoms such as altered consciousness, visualand vegetative changes, endoscopic opening of the tu- Given that hydrocephalus in neurocysticercosis can ber cinereum can allow removal of these cysts and be attributed to various mechanisms, it may be said improvement of the symptoms.
that the outcome will depend on its etiology. Intra- Surgical approach to the lateral or third ventricles ventricular cysts can be treated using endoscopic through a transcallosal or transcortical-transventric- techniques or a direct approach, as for cysts of the ular approaches is recommended for the treatment of fourth ventricle (Fig. 9) or of the periaqueductal re- Fig.9. a,b Axial and sagittal T1-weighted MRI.Fourth ventricular cysticercus and scolex.c,d Endoscopic views of the floor of
the third ventricle. MB, mammillary bodies; Aq, cerebral aqueduct; PC, posterior commissure. Note the cyst appearing inside
the fourth ventricle. e Endoscopic view of the cysticercus being extracted. f Sagittal T1-weighted MRI, 3-month follow-up
ing human tapeworm infection would be an alter-native control technique. The economic cost oftreating a case of tapeworm intestinal infection is150 times smaller than the cost of the same medica-tion used to treat neurocysticercosis [47]. At thepresent time there are two kinds of strategies rec-ommended by the World Health Organization: thefirst, for short term results, is based on widespreadtreatment of tapeworm infection and foci of trans-mission; the other, aimed at long-term results, fo- cuses on the development of breeding and inspec-tion techniques for pork, adequate sanitary mea- Fig. 10. Sagittal T1-weighted MRI. Mesencephalic hydatic
sures, and actions to detect and treat humans infected by tapeworms [47].
gion (Fig. 10). Communicating hydrocephalus result-ing from inflammatory blockage of the basal cisterns Other Parasitic Diseases Responsible
and treated by ventricular shunts (Fig. 6) may presenta higher incidence of complications [13]. Recurrent inflammatory reactions with CSF pleocytosis and in-creased protein levels due to the rupture of small in-traventricular cysts is probably one of the causes of these complications [13]. It is known that drug thera-py for neurocysticercosis is far from ideal and for the Histoplasma capsulatum is a dimorphic fungus that intraventricular forms of the disease is not efficacious exists as a mycelial form at ambient temperature and at all [63]. In a series that studied large groups of pa- as a yeast form in mammals. Its distribution is univer- tients, forms of neurocysticercosis considered hyper- sal, being endemic in certain regions of the United tensive comprised 20%-36% of the cases [48, 59, 66] States and Latin America [75]. The fungus exists in the and usually resulted in the worst outcome. Stepien soil of endemic areas, especially in dusty places where [59] reported on 43 patients who presented hydro- the soil contains bat or bird feces, such as for instance cephalus. There was improvement in only 12 cases a hen house [30]. The initial infection is due to spore (28%); 29 patients died (67%). In a study from the city inhalation. In endemic areas, almost the entire popu- of Ribeirão Preto (Brazil) of 500 patients in a period lation is infected and subject to multiple cases of re- of 23 years [66], 68 (13.6%) underwent some form of infection [72, 76].
CSF shunt diversion or surgical removal of cysts. Out Disseminated chronic histoplasmosis is a rare of 74 patients classified as having a pure hypertensive event, its incidence estimated at 1 per 100 000 to 1 per form of the disease, 21 (28.4%) died. Canelas [14] not- 150 000 infected individuals per year [30]. Sympto- ed that of 63 patients who underwent a surgical pro- matic CNS involvement is believed to occur in 10%- cedure, 28(44.4%) died. Takayanagui [64] pointed out 25% of the cases of disseminated histoplasmosis [18, that, of his series of 56 patients that presented with 45, 49, 74].
signs of increased intracranial pressure, 12 (21.4%) Shapiro classified the lesions of histoplasmosis of died and 12 developed incapacitating neurological se- the CNS as follows: (1) miliary granuloma; (2) histo- quelae. Studies concerning the intellectual develop- plasmoma; (3) meningitis/ventriculitis, the most fre- ment of these patients are extremely difficult, as quent CNS presentation, affecting preferentially the pointed out by Scharf [48], for each patient has a dif- skull base meninges; (4) spinal compression [30, 50].
ferent individual outcome depending on the lesions, The diagnosis of histoplasmosis is becoming more the number of parasites, the duration of the infesta- and more common due to an increase in the number tion, and the immunological response of the host.
of immunocompromised patients due to AIDS or im-munosuppression.Ventriculitis can progress to hydro-cephalus, requiring a CSF shunt. In most cases, many shunt revisions are necessary. In other cases, a parenchymal lesion is detected and a biopsy suggest- Control of neurocysticercosis demands attention ed. Histoplasma capsulatum should be considered in to hygiene habits and environmental sanitation.
the differential diagnosis even in cases of communi- Widespread medical treatment aimed at eradicat- cating idiopathic hydrocephalus (no associated Chapter 17 • Hydrocephalus in Neurocysticercosis and Other Parasitic and Infectious Diseases
meningitis or ventriculitis). A common factor among 3. Agapajev S, Alves-Moreira D, Barriviera B. Neurocysticer- all cases, irrespective of the clinical presentation, is the cosis:treatment with albendazole and destrocloropheri- insidious clinical course, characterized by numerous nami. Trans R Soc Trop Med Hyg 83:377-83, 1989 admissions to the hospital, a number of times because 4. Apuzzo MLJ, Dobukin WR, Zee C, et al. Surgical consider- ations in treatment of intraventricular cysticercosis. An of a shunt revision, with no etiological diagnosis.
analysis of 45 cases. J Neurosurg 60:400-407, 1984 The authors have treated eight cases of histoplas- 5. Aristotle. Historie des Animaux, vol III, book VIII, para XXI.
mosis, one being in a 12-year-old patient who had al- Paris, Societé d'Editions Les Belles Lettres, pp 48-49, 1969 ready undergone 28 shunt revisions and an erroneous 6. Bamberger DM. Successful treatment of multiple cerebral tuberculosis treatment. Another patient had had 16 histoplasmomas with itraconazol. CID 28:915-916, 1999 shunt revisions. After treatment the shunt complica- 7. Bandres JC, White AC, Samo T, Murphy EC, Harris RL. Ex- tions disappeared. One patient underwent an endo- traparenchymal neurocysticercosis: report of five casesand review of management. Clin Infect Dis 15:799-81, 1992 scopic third ventriculostomy that obliterated 3 8. Bérard H, Astoul PH, Frenay C, et al. Histoplasma dis- months later.
séminée à Histoplasma capsulatum avec atteinte cérébrale Another common characteristic shared by these survenue 13 ans après la primo-infection. Ver Mal Resp cases are the CSF findings. They are characterized by 16:829-831, 1999.
a modest increase in cell number, usually below ten 9. Bergsneider M,Holly LT,Lee JH,King WA,Frazee JG.Endo- cells, mostly due to lymphocytic/monocytic infiltrate, scopic management of cysticercal cysts within the lateral and modest hypoglycorrhachia or normal glucose and third ventricles. Neurosurg Focus 6(4):article 7, 1999 levels; protein content is always related to the phase of 10. Boppana S, Pass RF, Britt WS. Symptomatic congenital cy- tomegalovirus infection: neonatal morbidity and mortali- the disease. During recurrence episodes, levels are ty. Pediatr Infect Dis J 11:93-99, 1992 more elevated and protein/cell dissociation is more 11. Boudawara MZ, Jemel H, Ghorbel M, et al. Les kystes hyda- evident. Intraventricular protein levels are usually tiques du tronc cerebral. A propos de deux cas. Neu- above 1 g and may continue to rise even if external rochirurgie 4:321-324, 1999.
ventricular drainage is instituted.
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Please confirm you mean the whole of southern Africa, not just South Africa. "Natives" is a bit of a
problematic word - it would be better to find an alternative. Are you referring to all poor black popu-
lations, whether urban or not, or just those living a more traditional rural life outside the towns?
"Usually people are infected by eating contaminated pork; however, immune-suppressed persons may
become infected by contaminated pork" - presumably there is supposed to be a difference, since you
say ‘however' instead of ‘and', but what is it? Please clarify.
Please confirm "tissue" for "tecidual", which does not exist in English. Occurs again.
Please confirm "phase".
If you are giving anticonvulsant and cysticercocidal drug therapy, the patients cannot be said to be
drug-free. What are you intending to say here? That they became drug-free, rather than having chron-
ic drug treatment?
"To withdraw slowly" - does this mean "in order for the ICP to go down slowly", or does it mean the
dexamethasone is slowly tapered off at the end of treatment?
"Despite treatment with" replaces "despite the use of ". The sentence now suggests that patients may
have to undergo surgery despite having been treated with the drugs, rather than suggesting that, al-
though some patients can be treated with the drugs, others have to undergo surgery. Please confirm
the change is correct.
What is "clinical"? Medical?
[Q 10] Please confirm this is what was meant by "positivity".
[Q 11] Please give an abbreviated form of this journal title in accordance with Index Medicus style.
[Q 12] Same again, please.
[Q 13] Same again, please.
[Q 14] Please confirm legend for Fig. 6 (treatment algorithm).

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