Neurocysticercosis- cause, symptoms, diagnosis & treatment

Neurocysticercosis is brain infestation by eggs of Taenia solium (ie, pork tapeworm), usually due to contamination of food by people with Taeniasis. In developing countries, Neurocysticercosis is the most common parasitic disease of the nervous system and is the main cause of acquired epilepsy.

Sign and symptoms of Neurocysticercosis:

1. Epilepsy: Most common presentation (60-70%)
2. Headache, dizziness
3. Stroke
4. Neuropsychiatric dysfunction
Abnormal symptoms depends on where the cyst is located in the nervous system and include the following:
-Cognitive impairement
-Dysarthria
-Extraocular movement palsy or paresis
-Hemiparesis or hemiplegia
-Hemisensory loss
-Movement disorders
-Hyper/hyporeflexia
-Gait disturbances
-Meningeal signs

Diagnosis of Neurocysticercosis

Imaging

1. CT Scan- findings depending on the stage of evolution of the infestation:

Imaging depends on stages
Vesicular stage : Hypodense, nonenhancing lesions
Colloidal stage: Hypodense/isodense lesions with perilesional edema
Nodular-granular stage: Nodular-enhancing lesions
Cysticercotic encephalitis: Diffuse edema, collapsed ventricles, and multiple enhancing parenchymal lesions
Active parenchymal stage: Scolex within a cyst may appear as a hyperdense dot
Calcified stage: When the parasite dies, nodular parenchymal calcifications are seen.

2. MRI of Brain- is choice for neurocysticercosis,

Findings on MRI include:
Vesicular stage:  T2 hyperintense scolex seen, with no edema
Colloidal stage: Cysts are hyperintense with surrounding edema
Nodular-granular stage: The cyst wall thickens and retracts, lesser edema, and nodular or ring enhancement is present

Lab studies

Stool examination: 10% of Neurocysticercosis patients have Taeniasis
Brain biopsy: Rarely neede

MANAGEMENT (Neurocysticercosis Treatment)

Treatment is primarily against the symptoms
-Anticonvulsants - phenytoin, leviracetam- duration of the treatment remains undefined
-Steroids is recommended before the use of anticysticercal drugs
-Antiparasitic treatment-  Albendazole mainly for 21 days

Surgical Interventions needed rarely

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Hydrocephalus due to an intraventricular cyst- shunt requires
Multiple cysts in the subarachnoid space  Urgent surgical extirpation

Prognosis of Neurocysticercosis

Prognosis is usually good, but the duration of antiepileptics are undefined.