51 yr old male presented with abnormal behaviour.

A. Hydrocephalus with transependymal seepage of CSF.
B. Parenchymal calcification.
C and D. Multiple multiloculated CSF intensity lesions in bilateral sylvian fissures and suprasellar cisterns with no post contrast enhancement.

RACEMOSE NEUROCYSTCERCOSIS

DISCUSSION

Racemose neurocysticercosis

Invasive parasitic infection of the central nervous system caused by the larval stage of the tapeworm Taenia solium.
Most frequent cause of acquired epilepsy in the developing countries.
Parasitic infestation is endemic to South and Central America, Southeast Asia, China, and Sub-Saharan Africa.
Depending on the site of involvement, they are classified into intraparenchymal, extra parenchymal (subarachnoid-cisternal, meningeal, intraventricular) and mixed types.
The racemose variant of extraparenchymal NCC is characterized by the presence of multilobulated confluent cysts within the basal subarachnoid space that appear “grape-like” both radiographically and pathologically.
Clinical presentation can be variable.

Clinical manifestations of Racemose NCC

RADIOLOGICAL INVESTIGATIONS

Computed tomography (CT)

Sensitivity and specificity of more than 95% in the diagnosis of the parenchymatous form of neurocysticercosis.
Lower sensitivity and specificity for diagnosing the ventricular and cisternal forms.
Helpful in detecting calcifications.

MRI

The cisternal or ventricular forms of neurocysticercosis are readily visualized in MRI.
The cysts are usually larger than in the parenchymal forms and have a multilocular appearance, tend to displace neighboring structures, and behave as lesions with a mass effect.
The signal intensity is similar to that of the cerebrospinal fluid.
Normally do not show significant contrast enhancement; may show peripheral enhancement
Cysticerci usually do not contain scolices. If a scolex is seen, it is almost diagnostic/pathognomonic.
Conventional MR sequences such as T1- and T2-weighted images and fluid-attenuated inversion recovery images may miss intraventricular/cisternal neurocysticercosis cysts.
Three-dimensional (3D), very heavily T2-weighted sequences, such as constructive interference in steady state or fast imaging employing steady-state acquisition, are good sequences for evaluating intraventricular cysts.
Another MR sequence that is also useful is the 3D spoiled gradient recalled echo sequence, which provides T1 information.

DIFFERENTIAL DIAGNOSIS

Diagnosis

Positive hydatid serology will further be supporting evidence.
Serological tests (enzyme-linked immunoelectrotransfer blot assay, enzyme-linked immunosorbent assay) that detect anticysticercal antibodies in serum or CSF inherently lack specificity or sensitivity, thereby precluding their reliability in isolation.
MRI is the primary diagnostic modality used for the detection of cysticercus lesions and their secondary complications.

Treatment

Medical management with cysticidal agents, corticosteroids, and antiepileptic drugs
Surgical management to remove the cyst or to insert a shunt to treat hydrocephalus.

REFERENCES

Mahale RR, Mehta A, Rangasetty S. Extraparenchymal (Racemose) Neurocysticercosis and Its Multitude Manifestations: A Comprehensive Review. J Clin Neurol. 2015 Jul;11(3):203-211. https://doi.org/10.3988/jcn.2015.11.3.203
Sharma S, Singh A, Mani VE, Mishra SC, Chaturvedi P, Jain S, Kumar S, Jain N. Racemose neurocysticercosis: a case series. BJR Case Rep. 2024 Jan 19;10(1):uaae001. doi: 10.1093/bjrcr/uaae001. PMID: 38352260; PMCID: PMC10860505.
Krupa K, Krupa K, Pisculli ML, Athas DM, Farrell CJ. Racemose neurocysticercosis. Surg Neurol Int. 2016 Feb 5;7:12. doi: 10.4103/2152-7806.175881. PMID: 26958418; PMCID: PMC4766808.
https://www.ajnr.org/ajnr-case-collections-diagnosis/racemose-neurocysticercosis.

Dr. HARSHA CHADAGA
SENIOR CONSULTANT RADIOLOGIST AND HOD OF RADIOLOGY
MANIPAL HOSPITAL , YESHWANTHPUR, BENGALURU

Dr. VINEETH BABY
FELLOW IN CROSS SECTIONAL IMAGING
MANIPAL HOSPITAL , YESHWANTHPUR, BENGALURU