Unusual MR manifestations of neurocysticercosis

Racemose neurocysticercosis: a case series

Neurocysticercosis (NCC) is a common parasitic condition of the central nervous system in certain parts of the world. The racemose variety of NCC is distinct from the commonly seen parenchymal form. It frequently infiltrates the basal cisterns and Sylvian fissures. Imaging plays a vital role in the diagnosis; however, as their signal intensity is similar to cerebrospinal fluid and due to the absence of enhancement in most cases, imaging diagnosis is often difficult on the conventional MRI sequences. Here, we present five cases of racemose NCC to emphasize the importance of a heavily T2-weighted sequence (Fast Imaging Employing Steady-state Acquisition) sequence in the diagnosing this entity.

Endoscopic endonasal approach for isolated subarachnoid neurocysticercosis in basal cisterns and its complications: illustrative case

BACKGROUND

Neurocysticercosis (NCC) is an infectious parasitic disease in which humans are the middle host in the life cycle of Taenia solium. It is currently considered to be a neglected tropical disease. According to their location, cysts can cause epilepsy, hydrocephalus, arachnoiditis, and intracranial hypertension. The subarachnoid is the rarest and most morbid form among all forms of NCC presentation.

OBSERVATIONS

The authors report an odd case of subarachnoid NCC (SUBNCC). It was treated with expanded endoscopic endonasal surgery. Unfortunately, the patient developed a high-output nasal leak and meningitis after cyst removal, which demanded additional surgical procedures. Nonetheless, the patient showed a good clinical outcome after surgical interventions.

LESSONS

Endoscopic endonasal approach of SUBNCC can be safe and curative. Neverthless, the presented report shows that severe complications can arise from the procedure. The authors hypothesized that placing an early cerebrospinal shunt would reduce the patient’s morbidity before difficulties arose.

Conglomerate Ring-Enhancing Lesions are Common in Solitary Neurocysticercosis and do not always Suggest Neurotuberculosis

Background and Purpose:

Differentiating between neurocysticercosis (NCC) and neurotuberculosis has serious therapeutic implications and this distinction relies heavily on neuroimaging. Few case reports discuss the conglomeration of ring-enhancing lesions (RELs) in patients with solitary NCC. The aim of our study is to describe the imaging findings of conglomerate RELs in a cohort of patients with solitary NCC, emphasizing the frequency of conglomeration.

Materials and Methods:

This retrospective study included 100 patients with solitary NCC. Two neuroradiologists analyzed contrast-enhanced computed tomography (CT) images regarding morphology, enhancement pattern, location, number of lesions, and degree of perilesional edema. The solitary lesions were classified as solitary discrete RELs (SD-RELs) when a well-defined lesion was seen and solitary conglomerate RELs (SC-RELs) when two or more ring lesions or ring/rings plus disc lesions were present contiguously. Follow-up CT scans were evaluated for the resolution of lesions and surrounding edema.

Results:

Out of 100 patients, 42 were SD-RELs and 58 were SC-RELs. No statistically significant difference was found between both groups in terms of age of presentation, clinical presentation, lesion size and location, and degree of perilesional edema. Larger lesions (>10 mm) were more likely to show scolex and were associated with greater degree of edema in both subgroups. During follow-up, 13 patients had new lesions (SD-RELs-5, SC-RELs-8). In SD-RELs, follow-up lesions were in the same location in four patients and new location in one; and in SC-RELs, lesions were in the same location in seven and in new location in one case.

Conclusion:

Conglomeration of RELs is a common finding in patients with solitary NCC.

Transventricular neuroendoscopic excision of giant racemose subarachnoid cysticercosis

PURPOSE

Subarachnoid cysticercosis, an uncommon form of neurocysticercosis, can occasionally grow to giant size causing mass effect and obstructive hydrocephalus. These often require surgical excision to relieve the mass effect and re-establish the cerebrospinal fluid (CSF) pathways.

CLINICAL PRESENTATION

The authors report a rare case of giant anterior interhemispheric racemose cysticercosis with extension to the region of septum pellucidum causing obstructive hydrocephalus.

INTERVENTION

Due to the proximity of the cysts to the dilated ventricular system, a frontal transventricular endoscopic approach was preferred over a conventional microsurgical or endoscopic-assisted microsurgical approach. Most of the cysts could be successfully resected from the region of septum pellucidum and the anterior interhemisphere. The patient did not require a CSF diversion procedure in the postoperative period.

CONCLUSION

Depending on the location and nature of the lesion, a transfrontal transventricular endoscopic approach can be successfully utilized to approach lesions in the anterior interhemispheric region.

Giant parenchymal cysticercosis with unusual imaging features

Giant neurocysticercosis is a relatively rare condition. A 40-year-old woman presented with left focal seizures and progressive left hemiparesis. A CT scan of the brain showed multiple hypodense lesions in the right cerebral hemisphere with no contrast enhancement or perilesional edema. MRI showed multiple hypointense lesions in the right perisylvian area. At surgery, the lesion was found to be a single large parasitic cyst measuring approximately 5.0 x 4.5 x 5.0 cm and the same was excised. Histopathology showed a solitary cysticercus cyst with scolex. The patient made an uneventful recovery. This imaging appearance of giant neurocysticercosis is very unusual and only two similar instances have been reported thus far.

Giant neurocysticercosis cyst in the cerebellar hemisphere

A 67-year-old man presented with dizziness, nausea, and ataxia. Magnetic resonance imaging showed a large (5.5 x 4 x 4 cm) cystic lesion in the left cerebellar hemisphere with internal septation, a mural nodule, and thin rim enhancement. Cystic cerebellar tumor such as hemangioblastoma was initially suspected. Following surgery, the cyst was identified as cerebellar neurocysticercosis. Neurocysticercosis is the most common parasitic disease of the central nervous system but is occasionally misdiagnosed as tumor because of the varying neuroimaging presentation. This case shows that neurocysticercosis should be considered in the differential diagnosis of giant cystic lesions in the cerebellum as surgical intervention may be unnecessary.

Myocysticercosis: experience with imaging and therapy

OBJECTIVE

To compare computed tomography (CT) and B-scan ultrasonography (USG) in the diagnosis and to study the efficacy of a combination of oral albendazole and prednisolone in the management of myocysticercosis.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

Twenty-six consecutive patients with myocysticercosis.

INTERVENTION

Diagnostic imaging was performed by CT scan and USG in 24 and 22 patients, respectively; serial USG was obtained in 7 patients receiving treatment. All patients received oral albendazole (15 mg/kg body weight per day) and prednisolone (1.5 mg/kg body weight per day) for 4 weeks.

MAIN OUTCOME MEASURES

Presence of scolex on CT scan compared to USG and clinical response to medical therapy were the main outcome measures. Recovery was defined as complete resolution of the scolex or of the main presenting clinical feature.

RESULTS

Presence of scolex on CT scan (11 of 24) and USG (11 of 22) was not different (P = 1.0; chi-square test). Recovery was seen in 24 (92%) of 26 patients receiving medical treatment. On serial USG of patients receiving treatment (n = 7), cysts with scolex were seen to progress to a cyst without scolex before final resolution. Time to recovery on treatment (0.5-35 months) correlated with the duration of symptoms at presentation (correlation coefficient r = 0.56, P = 0.003, linear regression analysis), but not with positive serum enzyme-linked immunosorbent assay for anticysticercal antibodies (P = 0.57, log-rank test) or the presence of scolex (P = 0.52, log-rank test).

CONCLUSIONS

Treatment with a combination of oral albendazole and prednisolone is effective in the management of myocysticercosis. Imaging methods CT and USG are equally effective in identifying the cyst and the scolex; serial USG is useful in studying the temporal sequence of therapeutic response. The longer recovery time correlating with the duration of symptoms may indicate the chronicity of the inflammatory changes requiring longer time for recovery.

MRI of CNS parasitic diseases

This article reviews MRI findings of parasitic diseases of the central nervous system (CNS), with emphasis on neurocysticercosis, which is by far the most common CNS parasitic infection worldwide. MRI findings of neurocysticercosis are various, depending on the location (parenchymal, cisternal, ventricular, and spinal forms), and temporal evolutional stages (vesicular, colloid vesicular, granular nodular, and nodular calcified stages) of the worm. Classical findings of each location and stage are presented. Characteristic MRI findings of cerebral toxoplasmosis frequently seen in patients with acquired immunodeficiency syndrome (AIDS), paragonimiasis, and sparganosis that have most commonly been reported in East Asia are also illustrated. MRI is superior to CT scan in the evaluation of most CNS parasitic infections and is nearly diagnostic, particularly in endemic areas. Contrast-enhanced study is essential not only for specific diagnosis of the disease, but also for assessment of the inflammatory activity.

[Depressive disorders associated with neurocysticercosis: prevalence and clinical correlations]

OBJECTIVE

To determine the frequency and features of psychiatric morbidity in a cross-section of 38 outpatients with neurocysticercosis.

METHODS

Diagnosis of neurocysticercosis was established by CT scan, MRI and CSF analysis. Psychiatric diagnoses were made by using the Present State Examination and the Schedule for Affective Disorders and Schizophrenia. Lifetime version; cognitive state was assessed by Mini-Mental State Examination and Strub & Black's Mental Status Examination.

RESULTS

Depression was the most frequent psychiatric diagnosis (52.6%) as shown by PSE. Active disease and intracranial hypertension were associated with higher psychiatric morbidity, and previous history of mood disorders was strongly related to current depression.

CONCLUSIONS

Depression syndromes are frequent in patients with neurocysticercosis. The extent to which organic mechanisms related to brain lesions may underlie the observed mental changes is yet unclear, though the similar sex distribution of patients with and without depression, as well as the above mentioned correlations, provide further evidence of the role played by organic factors in the cause of these syndromes. The results of this study are discussed in the light of the data available for other organic psychiatric disorders.

Psychiatric manifestations of neurocysticercosis: a study of 38 patients from a neurology clinic in Brazil

OBJECTIVE

To determine the frequency and features of psychiatric morbidity in a cross section of 38 outpatients with neurocysticercosis.

METHODS

Diagnosis of neurocysticercosis was established by CT, MRI, and CSF analysis. Psychiatric diagnoses were made by using the present state examination and the schedule for affective disorders and schizophrenia-lifetime version; cognitive state was assessed by mini mental state examination and Strub and Black's mental status examination.

RESULTS

Signs of psychiatric disease and cognitive decline were found in 65.8 and 87.5% of the cases respectively. Depression was the most frequent psychiatric diagnosis (52.6%) and 14.2% of the patients were psychotic. Active disease and intracranial hypertension were associated with higher psychiatric morbidity, and previous history of mood disorders was strongly related to current depression. Other variables, such as number and type of brain lesions, severity of neuropsychological deficits, epilepsy, and use of steroids did not correlate with mental disturbances in this sample.

CONCLUSIONS

Psychiatric abnormalities, particularly depression syndromes, are frequent in patients with neurocysticercosis. Although regarded as a rare cause of dementia, mild cognitive impairment may be a much more prevalent neuropsychological feature of patients with neurocysticercosis. The extent to which organic mechanisms related to brain lesions may underlie the mental changes is yet unclear, although the similar sex distribution of patients with and without depression, as well as the above mentioned correlations, provide further evidence of the part played by organic factors in the cause of these syndromes.

Neurocisticercose no estado do Rio Grande do Norte: relato de oito casos

Os autores apresentam o estudo de oito pacientes com neurocisticercose encefálica no Estado do Rio Grande do Norte. Fazem comentários sobre a incidência da parasitose e referem as convulsões como o achado clínico mais freqüente, seguido pela cefaléia. O exame neurológico foi anormal em cinco dos oito pacientes. O diagnóstico foi baseado em achados da tomografia computadorizada em sete pacientes e do líquido cefalorraquidiano em três.

Parasitic infections of the central nervous system in children. Part III: Space-occupying lesions

In the last part of this three-part review of parasitic infections of the central nervous system in children, we consider parasites which due to their size, distribution, or the nature of the host response, tend to cause focal lesions in the brain and spinal cord and therefore present as space-occupying lesions which occasionally mimic malignant tumors. As in Parts I and II, infections are grouped according to their predominant geographic area. Such infections include cysticercosis, one of the more common and important infections of the central nervous system.

Central American mesencephalopathy

A 31-year-old Hispanic laborer sought medical attention for a four-day history of posterior headaches and double vision. The headache spontaneously resolved, but the patient continued to experience vertical diplopia. The neuro-ophthalmic exam revealed minimal anisocoria and subtle deficits of vertical motion of the left eye. MRI scanning demonstrated a lesion within the midbrain on the left side. Lumbar puncture revealed cells consisting primarily of lymphocytes and eosinophils. Both serum and cerebrospinal fluid revealed glycoproteins indicative of a cysticercosis infection. The patient was treated with Praziquantel and steroids with improvement of his oculomotor function.

Human cysticercosis: parasitology, pathology, clinical manifestations and available treatment

Human cysticercosis is a global health problem and neurocysticercosis a serious clinical syndrome. The diagnosis of neurocysticercosis can now be made with a high degree of accuracy by scrutiny of clinical signs and symptoms in combination with X-ray, computed tomography or magnetic resonance imaging, serological tests and laboratory examinations. Differential clinical diagnosis with tumor, and vascular and inflammatory conditions, may however, prove difficult in nonendemic areas. The management of cysticercosis has been radically changed by the advent of effective chemotherapy. Both the heterocyclic pyrazinoisoquinoline compound, praziquantel and the benzimidazole carbamate, albendazole, have now been extensively tested and successfully used for treatments of neurocysticercosis, usually in combination with corticosteroids. The definition of appropriate criteria and guidelines for the use of chemotherapy, may however, require further research. Surgical interventions continue to play an important role in certain clinical presentations. Recent advances in immunological research hold realistic promise for the development of a vaccine against Taenia solium.

Neurocysticercosis--a review of 231 cases

Two hundred thirty-one cases of neurocysticercosis are reviewed. Diagnosis was established by cerebral computed tomography during a seven-year period (1983-1989). One hundred and fourty-four (62%) presented with symptom-related disease (symptomatic neurocysticercosis and in 87 the diagnosis was incidental (asymptomatic neurocysticercosis). In symptomatic neurocysticercosis the parasitosis was considered inactive in 115 cases and active in 29. Seizures occurred in 135 patients (96% of the symptomatic neurocysticercosis). In the active form we also found: meningitis (n = 15), intracranial hypertension (n = 12), hydrocephalus (n = 10) and arteritis (n = 2). Treatment included praziquantel (n = 21), albendazole (n = 4), dexamethasone (n = 18) and surgery (n = 10).